LISA User Guide
Contents
1. The electro magnet position is given by two screws in slots gt Photo des deux vis de l lectro aimant dans deux positions extremes The tuning procedure is simple Puta cover on the telescope light entrance C INSTRUMENTS LISA a User Guide DCOO12A 60 67 Enlight the calibration window with white light ideally tungsten lamp If you have the calibration module use the flat lamp Untighten the electro magnet screws do not remove them Take a spectrum and evaluate the homogeneity of the spectrum along the slit The change is not obvious in the pictures below but it is more visible in live Spectrum too high Spectrum OK Spectrum too low I Sshelyak LISA User Guide DCO012A 61 67 Once you have found the optimal position tighten the two screws Your LISA is ready for calibration spectra acquisition 11 7 Appendix G Aligning the guiding mirror The guiding section of the LISA is made to control that star light comes into the spectrograph through the slit To work in good conditions it is key that the telescope axis is seen in the middle of the guding image The position of the slit is not tunable in the LISA the mechanical precision of the parts is enough to ensure that slit is right aligned with the 2 adaptor s axis then with the telescope However the optical path for guding image is quite complex and we must tune t2. INSTRUMENTS KA Shelyak Instruments Les Roussets 38420 Revel France Phone 33 476 413 681 http www shelyak com Email contact shelyak com LISA User Guide DCO012A Ref DCO012A 1 67 February 2011 Table of Content de MA OCR O sts canr sng eau wa raancetenecaacemsan aces aa naataeslewanaasee EE EEA ERE A EEES 4 DOU OF UNS OX a a a en ES 5 I OV VIEW OF Ue SR a a a 5 Cee Palomas lo eg a lag g ae een 5 3 2 CallOraunG the SPec anirien a T a S 7 3 3 Features SC performance s sssssssssrssrsrrsrrnnrsnrsnrenrsnernrnnrrnrrnrrnernrenernrrnernrrnrrnrrrrrnrrrernnn 10 3 4 Accessories optional elements sssssssssssnsssnnsssenssnnnsunsnssnsnnonsnronensenssnnnsunsnnrenesssnene 10 4 MeCNAnIE MIA LS RAC ana aan aan nada ae da ae ane da na aides dd nel 10 4A 1 1 Telescope IEC PAR de ao am ee dada ba ro 10 1 2 CED camera IMG IACe aan ane das een aa ab een cn 12 4 1 3 Guiding camera interface seen ecnenenennenenseuen 13 SAUNG SCA 13 Dal Setup your guiding Came a PR reo A a A 14 Didi TASCA O N ea A E E EEEO 14 5 1 2 GUIdinNg camera OS ae aa a ai one an 14 5 2 SEU your ACQUISITION CAMI FAL 222880 share dates Dis rendaient ancien 16 En A CS LE o p E E cos 16 Pe FOUE E AAE A E E a 19 Sa AINO a aN aE E EEEE 20 5 4 Checking the calibration screen ssssesssrnnssrensnrsrrnrrrrnnnrrnnrnrnnsnrerenrenrnrrnennrrrnnenrnnrnenn 22 Ty OR E A E 25 6 1 Operation to be done during da
3. Cambridge Astrophysics Series A reference book on the subject graduate level waxmemASstrophysics of gaseous nebulae and AGN ee Donald E Osterbrock amp Gary J Ferland AGraduate level book Specific subjects books CATACLYSMIC Cataclysmic Variable Stars Coe Hellier Excellent book on this subject including list of variables to take with your own spectrograph Non stable stars 1957 Georges H Herbig sAsteroseismology across the HR diagram fee Michael J Thompson Very interesting article compilation on this subject graduate level Articles can also be found on Abstract Data Services Asteroseismology Conny Aerts Jorgen Christensen Dalsgaard Donald W Kurtz ed Springer Written by professionnal experts in this field this recent book is a graduate sewe level but include some excellent and understandable parts including a great introduction to the subject lt LSshelyak LISA User Guide DC0012A 40 67 Asteroseismology den w ntroduction to close binary MUR W Hilditch Epsilon Aurigae a mysterious star system effrey L Hopkins amp Robert E Stencel 2009 Written before the 2009 2010 eclipse this book covers the knowledge on __ this very interesting system 27y periodic variable upernovae and stellar wind in interstellar medium Tatiana A Lozinskaya _ RR Lyrae Horace A Smith ed Cambridge Astrophysics Series 27 LA little bit disa
4. LISA User Guide DC0012A 25 67 8 Spectroscopy introduction 8 1 Inthe beginning Spectroscopy really started around 1666 when sir Isaac Newton dispersed sunlight with a prism But it s in 1802 that William Wollaston discovered dark absorption lines lines studied later by Joseph von Fraunhofer who published a catalog of several hundred of those lines in 1815 We now have classified thousands of absorption lines in the solar spectra In 1849 L on Foucault studied emission lines produced by a Sodium lap Gustav Kirchoff and Robert Bunsen identified the same lines in the solar spectra in 1857 solar spectra with a Lhires III O Garde 8 2 Different types of spectra Spectrography analyses light from sources away from us It allows the study if the chemical composition temperature pressure and movement r LISA User Guide DC0012A 26 67 INSTRU ENTS There are three types of spectra following the Kirchoff law 1 Continuous spectra it is emitted by any solid or gazeous body under high presure and high temperature Stars are under first approximation like black body whose continuous spectra has a shape which depends on its surface temperature 2 Absorption line spectra a low pressure low temperature gaz crossed by a continuous light absorbs some photons Spectra then shows dark lines in front of the continuous spectra 3 Emission line spectra a low pressure high temperature gaz emits a light ma
5. O AN ee ee E 33 8 6 Chemical composition and metallicity sesssnsnssnssssnsnsssnnsssenssnnnnnesssssnsnenensnsnnnanesnenene 33 Bai DODDICE EN C rrain n A a mannan 34 o ONCLUSION a E EE E EEEE E ER 34 Do TFOUBIESMOOCING SUD DON recseg rr ran EEA E EE 35 ci LSshelyak NEUI LISA User Guide DC0012A 2 67 iO Fei eh C OG avcnavaandoasucuvecen acncucatwacanhenteaubedes semua acwucacarkennetanaacaueasamrendansuagesenereaes 36 OS en nee Sea E A D ee et da 36 EOF WWD INKS SR a ae a E tn a 50 10221 CCI n SRE ER EE R E AOE 50 TO 2 ONNI ee nn 50 LL ADDON I Cee eee er ee cr ee re en E 51 11 1 Appendix A Add Automatic Calibration Module 51 11 2 Appendix B Opening closing the LISA sssssssssssssnssssnsssnnsssenssnnnsusnenenenensnnranennenene 57 LL Appendix C Switching from VIS tO IR en 68 11 4 Appendix D Switching from IR to VIS 72 11 5 Appendix E Tuning the grating angle ssssessssssssnssnssssnsnsnnsssenessanesnnnsnenensnnrnnerernene 72 11 6 Appendix F Tuning the calibration screen sense 75 11 7 Appendix G Aligning the guiding MirrOr sssssssssssssrsnsnrsrenrsrrnrsrrnnrrenrenrerenrerenrrnnrnrnne 77 11 8 Appendix H Focusing amp aligning the collimator RS 80 Pio Appendix I Factory tuning DrOCCSS aa ERNE 82 ci LSshelyak NEUI LISA User Guide DC0012A Se 1 Introduction This document will help you to use your LISA high luminosity low resolution spectrograph We consider tha
6. further release of this user guide 10 1 Books Note see our web site for a more complete list of bibliography http www shelyak com dossier php id_dossier 35 amp lang 2 First check the link http www ursusmajor ch astrospektroskopie richard walkers page index html Scroll down the web page to get the english version of Richard Walkers free book on spectroscopy An excellent first read Here is a list of several book which are related to Spectroscopy Some of them are must have in your private library Historical Books Astronomical spectrographs history ohn B Hearnhaw ed Cambridge While the book is thin and expensive it is a must have for those interested in spectrograph s history Very well documented Mieke The analysis of starlight ag WOhn B Hearnhaw ed Cambridge Ai Out of print book A reference for anyone interested in spectroscopy in S general and history in particular State of the art book with detailed reference s list A must have pectroscopic astrophysics contribution of Otto Struve Georges H Herbig _ Very interesting compilation of article to get an overview of astrophysics in Jearly twentieth century Articles can also be found on Abstract Data Services but they are all followed by an update of the knowledge in the 1960 s lt LSshelyak LISA User Guide DCO012A 31 67 Spectroscopy books Stars and their Spectra an introduction to the spectral sequence Jam
7. http astrosurf com buil us book2 htm CDS Strasbourg http http cdsweb u strasbg fr This is THE reference for any astronomical object Look for key information browse through hundreds of catalogs and link to professional work done on any specific object ADS http adsabs harvard edu abstract_service html This is THE reference where to find for professional articles Thousands articles are scanned and available to the amateur community through that link 10 2 2 Software Iris http www astrosurf org buil us iris iris Atm RLhires http astrosurf com buil rlhires tuto1 htm VisualSpec http astrosurf com vdesnoux Audela http audela orgq dokuwiki doku php id fr start SpcAudace http bmauclaire free fr spcaudace lt LSshelyak LISA User Guide DC0012A 45 67 11 Appendix 11 1 Appendix A Add Automatic Calibration Module Calibrating precisely the spectrum is key to use it for scientific application An optional calibration module can be added on the LISA to remotely control the instrument This calibration module contains both halogen for flats and neon for wavelength calibration lamps Here is how to proceed to install it Remove the screw on LISA side same side as the calibration window Remove the calibration window cover Take the calibration module and insert the plug into the LISA connector for calibration screen activation Adjust the calibration module onto
8. make sure to use longuer distance between the LISA and the focal reducer to get the required F 5 input to the spectrograph Secure it so it can t fall down Check the total weight capacity of your mount if needed Align the spectrograph in order to have the slit parallel to the RA movement If you plan to observe low on southern horizon it may be worthwhile to align on the Dec movement as the turbulence is mainly toward that axis and the refraction effect is also on the vertical axis And of course balance your overall setup very carefully 6 1 2 Check Fine tune adjustments focus guiding focus LISA acquisition focus telescope During dawn time or using a lamp in front of the telescope check the position of the slit on your guiding camera Record this position on your guiding screen Check the focus by taking a calibration Neon spectrum Measure the FWHM Full Width Half Max of a line near your camera chip center to ensure it close to what you had during the instrument setup 6 2 Standard acquisition procedure 6 2 1 CCD master frames Thermal Offset Dark Bias Dark Exposure t Exposure 2t Exposures t Osec shutter ttt closed LISA User Guide DCO012A 20 67 TMHSTRUPENTS If you use a CCD camera each image will be affected by the electronic Several defect can actually be removed using Bias and Dark frames To avoid negative signal digital conversion CCD manufacturers add a fix offset
9. on the analog signal which is called Offset or Bias Any data readout from the CCD chip include this offset This offset is fairly stable and once you have a master Bias frame you can keep it for long time You can make one again once per year approximatly It is also not too much temperature dependant Because it is very stable you can improve your data by taking a long series of bias frame around 100 exposures and perform a median average to create a mooth master bias frame for your camera Median average is better than a simple average as it will totally remove out of the ordinary defect on some of your images such as cosmic rays for example CCD chip have a tendancy to build electrons over time specially at high temperature This temperature dependant effect is called thermal noise The thermal noise is included in dark frames which are exposures taken with the camera shutter on the offset is also included in Hot pixels are individual cells that are particularly sensitive to this thermal noise and tend to saturate quickly during long exposure Those hot pixels will have to be processed separately usually replaced by the average of the surrounding pixels An interesting property of thermal noise is that it is linear to the exposure time For exemple a thermal noise of a 2sec exposure is twice the thermal noise of 1sec exposure This means that you can extrapolate any shorter thermal noise frame from a master thermal noise frame with
10. screen We have seen in practice that the LISA spectrograph is rather stable Still to get the maximum accuracy in calibration it is sometimes critical to be able to perform calibration while the LISA spectrograph is mounted at the telescope For this a small window is available on the side opposite side of the slit In addition a small white screen can be moved electrically in front of the slit 1 LSshelyak NEUI LISA User Guide DC0012A 17 67 See i gt M A N iair VA Ht if LH DAY Le Es Pip 1 A H y S ar q a AR QE gt 2 LEZ p Eh kd S Hota ET EH Ma y E gn A if j Sit EA j H AN 1 A AN y gt ne F tin es a L o a aS if _ i You should check that calibration screen works properly before installing the spectrograph on the telescope For that plug a 12V power supply You should hear a click sound that confirms the electromagnet is Ok By looking from telescope light entrance you can see the screen moving in and out when you supply and remove 12V Note that an electronic board is inside the LISA spectrograph to send a short pulse to activate the screen then reduce the voltage to prevent heat dissipation Untighten partially the two screws of the calibration window cover INSTRUMENTS LISA User Guide a DCOO12A 18 67 Remove the cover by rotating and pulling it You can see the calibration window c
11. the slit image is perfectly focused Be careful this process is valuable only if your optical device have been focused at infinite first C INSTRUMENTS LISA Es User Guide a DCOO12A 65 67 Slit not focused Slit focused Once the optimal position is found tighten back the collimator screw To make the instrument properly aligned we then must tune the collimator axis towards the slit center We use an autocollimation process to do it Put all your setup in a dark room very dark Enlight the slit with an intense lamp for instance white LED just in front of the slit Puta mirror against the collimator holder Look at the slit image close to the slit itself When the alignment is correct both slit and slit image must be confused To change the alignment untighten the collimator holder and rotate it gently until slit and images are aligned INSTRUMENTS LISA Es User Guide a DCOO12A 66 67 Collimation not good Collimation Ok If you need to give an inclination angle to the holder put a small piece of paper between holder and chassis Once the alignment is optimal tighten back the two collimator holder screws Mount back the grating holder see appendix C Close the LISA see appendix B Tune the grating angle see appendix E Your LISA is ready for observation 11 9 Appendix I Factory tuning process Here is a quick list of all operations that
12. STRUMENTS LISA Es User Guide a DCOO12A 57 67 Defining the best grating angle is necessary for Getting the expected wavelength bandwidth in the CCD surface Getting focused lines in the widest banwdwidth The grating angle is easy to change Remove the side door below the slit zT a gt uh yi wer we Untighten the two screws on the grating holder do not touch to the central screw it is the rotation axis of the folder Caution Do not remove the screws the grating would fall down into the instrument Use the grating lever in the door opening to precisely change the grating angle and tighten back the screws ht Ly pi TAH DIR wera SHE TE shout ak DIH wie SHEL C INSTRUMENTS LISA Es User Guide a DCOO12A 58 67 When you change the grating angle the spectrum will be moved horizontally along wavelength axis in the image Make some tests move the grating lever by a very small angle and look at the effect in the image Train yourself to put a given spetrum line at a given position pixel X in the image The two configurations VIS and IR have of course different grating angles A Configuration VISIBLE We suggest to use aNeon spectrum to tune the angle In this Neon spectrum locate the 5 lines pattern around Ha 6563A and specially the central line of this group 6598A 1 4 E E MMT TE This reference line must be at 2 716mm at the right
13. a parameter in the kappa sigma rejection method or sigma clipping for staking images see COMPOSIT or COMPOSIT2 commands 7 6 Wavelength calibration Extract your Neon calibration spectrum exactly the same way you have extracted your object spectrum specially in terms of geometrical correction and spectrum extraction area Use this Neon spectrum profile to calibrate your object amp reference star spectra by using a non linear wavelength polynomial law 7 7 Instrumental response Divide your reference star spectrum by a spectrum from a catalog of a star of same spectral class amp type Smooth the division to remove all local spikes due to absorption lines amp atmospheric lines The result is your instrumental response which you can save and archive It is not mandatory to make an instrumental response every night but worthwhile to check it s still valid from time to time Divide all your extracted amp wavelength calibrated spectra by this instrumental response to get your final spectral profile ready to be shared with others and or to be analyzed 7 8 Software RLhires is a free software written by Christian Buil to process Lhires III spectra It can actually also be used to process LISA spectra Refer to the on line tutorial for further information RLhires does perform all operations described above in a single package ci LSshelyak NEUI LISA User Guide DC0012A 24 67 There are several softwares that exist which ca
14. ancois cochard shelyak com bit LSshelyak NEUI LISA User Guide DC0012A 4 67 2 Out of the box When you receive the your LISA you should find these elements 3 The LISA spectrograph A tool set if you need to tune the instrument The CCD camera adapter Documentation Depending on your order some optional elements Calibration module IR conversion kit Overview of the LISA LISA is a luminous slit based spectrograph F 5 designed to observe faint or extended targets It is mounted directly on the telescope and includes a guiding feature 3 1 The Basic Elements To optimize the use of your LISA spectrograph it is important that you keep in mind the key principles of the instrument Here is a short description of its interior The LISA is made of two main parts on top there is the guiding unit which includes parts dedicated to calibration see blue section in figure 1 In bottom there is the spectrograph by itself green section in figure 1 Guiding section Se Spectro section Figure 1 guiding and spectro sections Figure 2 is a drawing showing main elements of the instrument There are three mechanical links to external elements the telescope mounting the guiding port and the spectrum aquisition port ci LSshelyak NEUI LISA User Guide DC0012A 5 67 telescope mount Calibration window Guiding optics Guiding mirror reflecting slit Guiding port Grating holder Grating t
15. are good choices 7 Processing This will detail one way to process your spectra There are many other paths to come to the same or very similar results 7 1 Preprocessing This is a very similar step as for any other CCD imaging Most astronomical software include some preprocessing functions and can also create your master Bias or Dark frame The simpliest preprocessing is to substract from each of your object spectra a dark frame taken with the same exposure time and at the same temperature The difference is that you should use a PRNU frame as your flat field or use the high frequency of your Flat tungsten spectrum Simply smooth your Flat spectrum with a gaussian filter and divide your Flat spectrum by this smoothed one to get your high frequency Flat spectrum which can be used as standard CCD imaging Flat field 7 2 Geometry Your individual spectra should be corrected from geometrical distortions A spectrum not fully horizontal ie rotation to perform from the center of the image B spectral lines not vertical ie slant or tilt to correct on your spectrum C spectral lines not straight lines ie smile effect to correct on your spectrum If you properly align your camera step A may not be required Also as spectral line from LISA are fairly straight it is usually not required to do step B or C If you apply any geometrical change make sure to apply the exact same geometrical correction to your calibration frames
16. as well 7 3 Remove background Before extracting your spectra it is critical to remove any background spectra Because LISA is a long imaging slit spectrograph it usually capture your star spectrum but also any other light coming through the slit human light pollution earth atmosphere emission lines such as OI lines which create very nice aurora Those pollution are easy to remove by substracting the background above and below your spectrum 7 4 Combining spectra You can combine your 2D images using an addition or better a sigma kappa addition It is also possible to first extract the spectral profile of each individual spectra and combine the profiles Choice is yours and you can check the difference between the two Somehow we have found the on very faint and noisy spectra combining the 2D image was best but in most of the case combining the profiles were more efficient in the case of LISA spectra 7 5 Extracting spectra The easiest extraction is to take the lines with the highest signals and to sum column per column the ci LSshelyak NEUI LISA User Guide DC0012A 23 67 pixel values The optimal extraction method consists to assign to each pixel when the summation takes place a weighting factor proportional to the amount of the signal in it See papers e J C Robertson PASP 98 1220 1231 November 1986 coded and adapted in the command L_OPTBIN in IRIS software e K Horne PASP 98 609 617 June 1986 cod
17. book The largest star the brightest star the most massive star wen he hundred greatest stars MU ame B Kaler meeJames Kaler writing makes it a general public book He is highlighting 100 stars which are all of some interest e Wourney from the center of the Sun T Yack B Zirker ed Princeton Science Library Excellent book covering our knowledge of our star but also all the mysteries still to resolve and there are a lot Technolo books AOptical Astronomical Spectroscopy SSC R Kitchin MMOne of the reference book for spectrograph builders lt LSshelyak LISA User Guide DCO012A 43 67 Diffraction Grating Handbook Richardson Grating Labotary Some interesting information in this free book useful for instrument eg Duilders Handbook of CCD Astronomy Steve B Howell An excellent but serious book on CCD technology Everything about Signal noise J Shelyak TNSTRUMENTS LISA User Guide DCO012A 44 67 10 2 Web links 10 2 1 General Shelyak Instruments http www shelyak com This is our web site where you can find additional information on your LISA spectrograph more ideas for projects etc ARAS home page http www astrosurf com aras ARAS is an amateur professional group with objective to promote spectrography Spectro L list http groups yahoo com group spectro Christian Buil web site http www astrosurf org buil Christian s Spectro bookmark
18. can also be found on Abstract Data Services Pulsation rotation wind and magnetic field in early B type stars Coralie Neiner hesis on the subject graduate level Articles can also be found on Abstract Data Services and magnetic field in The early type stars Anne B Underhill POOKk to place into context for collectors LISA User Guide DCO012A 38 67 INST RUPE H TS Variables stars books Meee Understanding variable stars meee ohn Percy ed Cambridge 2008 fee ohn Percy wrote several article in Sky amp Telescope This book is an de emexcellent recent overview of variable stars with key tables listing targets for your spectrograph A top book to own in your personal library Q Getting the measure of the stars W A Cooper amp E N Walker J he book is focused on photometry as amateurs were doing very few spectroscopy at that time The book goes through the HR diagram and thighlight where amateur can contribute still the case today ET Variable stars observers handbook Sohn Glasby Old book mainly for historical purpose Observing Variable Stars Roce Gary A Good ed Springer D _ Gaz amp Nebulae books Physics and dynamics of planetary nebulae Grigor A Gurzadyan Obviously translated this is a graduate level book LISA User Guide DCO012A 39 67 TIMHSTRUPENTS es Origin and evolution of planetary nebulae Sun Kwok ed
19. d Cover don t have the same height the splitting line is not in the middle of the instrument Remember that the Chassis is the thinest part and the Cover the thickest LISA function of main screws Function of LISA screws Guding camera Focus lock Calibration screen Electro magnet tuning Guiding spectro partition Grating holder af Slit holder Collimator holder Opening door Focusing amp Grating angle Main mirror holder OPENING Both parts can be separated To do so follow strictly these instructions Remove the LISA from the Telescope lt LSshelyak LISA User Guide DCO012A 48 67 Remove CCD camera and guiding camera Remove 2 screws M3x10mm from the the Chassis side Remove 2 screws M4x10mm from the CCD camera plate side Cover side Untighten 9 screws M3x10mm all around the spectrograph on the Chassis These screw must be left in place no need to remove them completely Remove the two side doors remove one big screw for each and slide the doors towards the CCD camera c She heklyak LISA User Guide DC0012A 49 67 Catch the instrument like on the picture put one thumb in each door opening CCD camera holder towards yourself Slighltly open the instrument keeping both sides parrallels This can be quite difficult the first time do it very carefully If necessary use a small tool like a screwdriver to
20. d for standard adaptors or to mount directly a DSLR with T ring The backfocus of the T mount standard is 54 85mm from flat face to the focus point The tuning range for LISA allow to put the focus plane CCD plane at 5mm of this position CCD camera Guiding camera focus plan INSTRUMENTS LISA User Guide DCO012A 10 67 4 1 3 Guiding camera interface The guiding port is a C mount 1 diameter 32 thread inch backfocus 17 5mm used by several guiding camera and is a standard among video camera 5 Starting amp tuning This is now time to start working with your LISA We ll describe how to install cameras on it tune it and check its behavior is nominal Important all this task can be done during daylight Install yourself in good conditions with a large table and enough light It is preferable to do these operations in relative darkness to prevent any light pollution when the spectrograph is open 5 1 Setup your guiding camera In this section we ll install the guiding camera on the LISA We consider that you know how to use and control it 5 1 1 Installation Untighten the locking screw of the guiding port Remove the guiding camera holder and screw it carefully on the camera There is no tuning at this Stage the lense are put at the right position for the guiding camera by mechanical design INSTRUMENTS LISA Es User Guide a DCO012A 11 67 Slide the camera with its hold
21. de of few radiations characteristics of the atoms that constitutes this gaz Each chemical element has its own line spectra true identity card of its composition and state An important property of those absoprtion and emission spectra is that lines are emitted at the same wavelength that they are absorbed 8 3 Message from light Spectroscopy was extended to the study of stars and nebulae in which new elements were discovered Sir Norman Lockyer and Jule Janssen discovered in 1868 during a solar eclipse a new element which has been isolated on Earth in 1895 Helium Johann Balmer developed an empiric formula in 1885 for the position of hydrogen emission line Ha Hb Hg This formula was extended to other elements by Johannes Rydberg But it s Niels Bohr who brought in 1820 a theory to the spectral line process The Bohr model is based on quantum theory and electronic clouds around atomic nucleus Astronomy faced a revolution an evolution toward Astrophysics The language of light was just decrypted Coded light is rich of lof of information e on effective temperature at the surface Wien law e on radial rotation and expansion movement Doppler effect e on stellar density and pressure e on chemical composition Wye LISA User Guide DC0012A 27 67 TNSTRUMENTS 8 4 Effective temperature and spectral types Stars are almost like black bodies They emit energy at all wavelengths with a continuous spectra Its sha
22. ed and adapted in the command L_OPTBIN2 in IRIS softare From IRIS documentation The Robertson s algorithm L_OPTBIN command is applicable only when the detector columns are perfectly aligned perpendicular to the dispersion direction If it is not the case at the acquisition time a post operation consist for example to apply the TILT command Although L_OPTBIN is still useful because it is robust and fast method and yields good results if such a small misalignment is present The Horne s algorithm L_OPTBIN2 command is very time consuming fit of many low order polynomials along the spectrum It work for tilted or distorded spectra But attention this algorithm cannot be used if variation in the fraction of starlight falling onto pixels have a more complex form than can be fitted with low order polynomials So generally we prefer use the Robertson algorithm and manual geometric correction of the spectrum command SLANT TILT SMILE For this two commands it is necessary to give estimation of the mean sky level in ADU Analog Digital Unit or Counts But very important before application of L_OPTBIN or L_OPTBIN2 the sky is removed of the processed image use L_SKY L_SKY2 L_SKY3 The following parameters are the electronic gain of the camera in electrons ADU and the readout noise RON of the CCD camera in electrons A final parameter kappa is a coefficient for adjust cosmic or hot spot rejection process similar to the kapp
23. er in the LISA Put the camera parallel to the LISA chassis Put it roughly at the same position as the picture 5 1 2 Guiding camera focus Put a diffuse paper in front of the telescope mount or move the telescope mount towards some difuse light Take a guiding image choose the exposure time to prevent any saturation You should see an horizontal line eventually very large This line is the slit Move slightly the camera in order to get the best focus You ll see that when you turn the camera the slit rotates on the screen It must be put horizontally Wrong position of the guiding camera Good position of the guiding camera lt PShelyak LISA User Guide DC0012A 12 67 Tighten the top screw to lock the guiding camera in position At the end you should have this image on the computer screen Do not remove the guiding camera from the LISA until you install it on the telescope If you have to remove the camera from the LISA you will have to re focus it The guiding mirror alignment have been done in our factory before shipment Then the slit should be right in the middle of the image vertically If this is not the case you may retune this point It is described in appendix D Not acceptable too low Correct alignment Not acceptable too high 5 2 Setup your acquisition camera In this sec
24. es B Kaler While this book is getting old and some would prefere Spectral Classification from Richard Gray James Kaler book on spectral classification is of easier access for amateurs One of the top book to have in your personal library Spectral Classification Richard O Gray amp Christopher J Corbally 2009 A recent and complete book on spectral classification It superseeds somehow Jaschek amp Jaschek book on the same subject One of the top mal OOK to have in your personal library STELLAR CLASSIFICATION Observation and analysis of Stellar Photospheres Le an David F Gray 2 PSone of the top book to have in your personal library Graduate level with Wa alot of figures spectra and exemples aInterpreting Astronomical Spectra NTERPRETING mm Emerson While a little bit old this book contains soe very interesting references Superseeded by David Grays stellar photosphere book D Emerson tellar Spectroscopy Peculiar Stars Hack amp Struve Small but very interesting book with exemples and ideas for your own spectrograph to work on Second part Stellar Spectroscopy Normal Stars Hack amp Struve Small but very interesting book with exemples and ideas for your own spectrograph to work on First part LISA User Guide DCO012A 32 67 INSTRUMENTS The behavior of chemical elements in Stars Carlos Jaschek amp Mercedes Jaschek as his books lists per element
25. he guiding mirror to make the center of the slit in the middle of the image The simplest way to tune the mirror angle is to use the tuning slit with one 19um hole right in the middle This devices makes very visible where is the center of the slit which is aligned with the telescope axis The guiding mirror is mounted on a holder that can be moved with 4 screws accessible from the telescope light entrance the guiding mirror cannot be tuned when mounted on the telescope INSTRUMENTS LISA User Guide a DCOO12A 62 67 The central screw is a rotating axis don t remove it Here is the procedure to tune the guiding mirror Install and switch on the guding camera The slit must be well focused and horizontal Untighten the two external screws The following pictures show how the guiding mirror holer is made Rotate the mirror holder around its axis the slit position will move horizontally C hal 112 INSTRUMENTS LISA Es User Guide a DCOO12A 63 67 You can also tune the vertical position of the slit in the image by tightening one of the headless screws These screws are made to give an angle to the mirror holder gt Note in the last picture on the right slit in too low position there is a mark on top side of the screen This mark is made to show the center of the slit In some cases it can be useful to find where is the
26. ide to send calibration light in the isntrument A white screen controlled by an electro magnet can be moved to send calibration light to the slit The electro magnet is supplied by an electronic circuit which prevents any heat dissipation When this screen is in front of the slit it prevents star light to enter in the spectrograph Then you can make calibration acquisitions even when the telescop is pointing a star In the drawings hereafter you can see the light opening on the spectro side yellow the mobile white screen the electro magnet and the electronic PC board green _ 3 LS Yo LA li AS Sr HH 3 i SR D i k A HC By Y INSTRUMENTS LISA User Guide a DCOO12A 7 67 An optional calibration module is available it enlights the calibration window with white light halogen lamp for flats and Neon lamp for calibration 3 3 Features amp performance Visible mode spectral domain 400 700nm Near IR mode spectral domain 650nm 1um CCD cameras usually limit around 950nm Resolving power 600 1000 depends on slit and mode Slit 15um 19um 23um or 35um optional slit 19um hole 50um 75um 100um slit Slit length is 4mm Backfocus telescope 41mm distance from the top flat face of the LISA to the slit Backfocus CCD camera T mount standard 54 85mm Backfocus guiding camera C mount standard 17 5mm Connecteur 12V de calibration 2 5mm positive
27. in the center c INSTRUMENTS LISA User Guide a DCOO12A 8 67 3 4 Accessories optional elements Shelyak Instruments can provide you with some optional elements to complete your LISA setup Calibration module see above IR conversion kit to change the observed bandwidth to 600 950nm Several CCD camera adapters Eyepiece holder For any other specific need do not hesitate to contact us 4 Mechanical interfaces 4 1 1 Telescope interface LISA front plate includes a standard T mount thread M42x0 75mm Backfocus is 41mm distance from the top flat face of the instrument and the slit position For your convenience the LISA is shipped with a M42 2 adaptor This is the simplest way to mount it on a telescope INSTRUMENTS LISA User Guide DCO012A 9 67 4 1 2 CCD camera interface The acquisition CCD camera is mounted on the camera interface LISA is shipped with an adaptor for QSI cameras ws body profile Depending on your camera we can provide different adaptors Most CCD camera have a T mount thread and this is the best way to attach it on the LISA All Lhires III CCD camera adaptors are compatible for your LISA spectrograph as both instruments have the same spectrum port backfocus LISA adaptor have two threads Internal thread is M35x1mm It is used for Shelyak adaptors such as the QSI one External thread is T mount standard M42x0 75mm 54 85mm backfocus It can be use
28. isible and Infra red The standard configuration is Visible You can switch IR configuration using the IR conversion kit provided as an option by Shelyak Instruments There are three differences between VIS and IR configurations The grating is different VIS is blazed at 500 nm IR is blazed at 1000nm There is a blocking filter after the slit in the IR configuration to prevent any second order spectrum mixed with the IR part of the first order The CCD camera spacer makes an angle of 4 with the spectrograph face to ensure a good focus on a large spectra range C INSTRUMENTS LISA Es User Guide a DCOO12A 53 67 To switch from VIS to IR configuration follow these instructions A Changing the grating Open the LISA see appendix B Untighten the two external screws of the grating holder in LISA Keep in place the central screw it is used as a simple rotating axis DIN HE Ce P en i ERP a ER Maintain securely the grating holder when removing it Take care to never put the finger on the grating surface it would be definitely destroyed F Remove the grating lever from the holder 2 screws aa TT im j j T a ULA Bk LE En DS Jot i WPA i ia af era i w To F F gall 7 is DE i el 1 i KAI r A ur Au gt M de EP LE 1 t l ve a re t dl i y lt k r 1 JD NeLyer LISA User Guide DC0012A 54 67 Take the IR grating from the conve
29. lamp with Argon Energy saving lamp 6 2 3 Object frames It is recommended to take more than one single exposure to be able to combine your individual exposures into a single one This will allow to remove for exemple cosmic rays from some exposures A good combination is the sigma kapp addition which basically adds all frames pixel by pixel except the one with pixel value out of the ordinary In mathematical terms we do not include pixel values outside a k sigma of the lot Some software can do a first pass to remove some pixels really far from the average and a second pass to remove some other ones For a sigma kappa addition to work you would need several exposures about 7 to 11 of those Of course you do not want to cut your overal exposure time in too many frames as it not only adds overhead CCD read out time but also add read out noise on your final image In general it is a good habbit to divide your overal time by about 7 frames and to not have single exposure more than 15minutes But this is a general rule and you can of course adapt to your own need Exemple of object spectrum M42 Orion nebula the trail is the star spectrum the vertical lines are emission from the nebula WYO LISA User Guide DC0012A 22 67 INSTRUMENTS 6 2 4 Reference star spectrum During the night take spectra of a reference star Typically a non variable non binary A type star with mainly balmer lines Vega and Regulus
30. lear window 10mm diameter You can inject some light through this window tungsten lamp neon lamp energy saver lamp and take an image you ll have the spectrum of this calibration lamp This spectrum must be roughly homogeneous along the slit If this is not the case you could improve the electro magnet tuning see appendix F For instance here is Halogen lamp spectrum made through the calibration channel At the end replace the cover and tighten smoothly the two screws Shelyak Instruments can provide an optionnal device to get white halogen and neon light in order to remotely control the LISA Mounting this device is described in appendix A lt LSshelyak LISA User Guide DC0012A 19 67 6 In the field Once you ve made all adjustments of the instrument you re ready to acquire your first star spectra This section describes the operations to do at every observation 6 1 Operation to be done during daylight As often in spectroscopy part of the preparation operations can be done during daylight it s even preferable We consider that your telescope is ready and you CCD camera as well 6 1 1 Mounting the LISA on the telescope Be sure that the instrument is strongly attached to the telescope using the 2 50 8mm and if required a focal reducer or a barlow to bring your telescope F ratio to F 5 If you have a Schmidt Cassergrain Telescope you could use a F 6 3 focal reducer and a SCT T adapter
31. lis Part of Springer serie on Astrophysics Like most books of the serie the Yee subject is briefly reviewed but in a simple manner which several shall like ntroduction to the study of stellar structure S Chandrasekhar An interesting book to take into the historical context of that time ET ATMOSPHERES tellar atmospheres Mihalas Old book but still a reference to place into the context of his time lt LSshelyak LISA User Guide DCO012A 35 67 Theory of stellar pulsation ohn P Cox ed Princeton University Press his book has been a key reference at that time A little bit old now New perspectives on stellar pulsation and pulsating variable stars IAU139 ames M Nemec amp Jaymie M Matthews Graduate level compilation of article from International Astronomical Union colloguium 139 Some would prefere more recent work such as annee s Asteroseismology across the HR diagram Articles can also be found on Abstract Data Services Tonnes he Physics of Stars B C Phillips ed Wiley Graduate level book An introduction to the theory of Stellar Structure and Evolution tes IDina Prialnik 4 Graduate level book with an interesting high level first chapter Includes Wee also the maths for spectroscopic binaries study dvanced stellar astrophysics tee William K Rose Astrophysics Graduate level book Ae Foundations of Astronomy wan Michael S Seeds of Enclypedia type b
32. long exposure assuming you have mapped the hot pixel properly This is done by doing a median average of a a long exposure dark frame serie at least 7 frames if possible more Most astronomical software require both the biad frame and the dark frame to pre process your image The thermal noise is of course embeded in the dark frame Be very careful as the thermal noise thus the dark frame is very sensitive to temperature Make sure to use a Dark frame taken with the same temperature as your spectra If your camera doesn t have a temperature regulation you should take dark frame close to the time you expose your spectra Some software can still extrapolate a proper thermal noise map based on the area of your chip with no signal which is very easy in the case of LISA spectra You do not have to rebuild your dark frame every night ou can create your library of dark frames taken at different temperatures and use it for several months Last but not least is the Pixel Response Non Uniformity PRNU which is often measured by taking an uniform field flat field with your camera and telescope in imaging You could do the same by putting a diffuse paper or even a camera lens in front of your camera In practice the spectral flat see below will be sufficient 6 2 2 Calibration frames Calibration frames should be taken at least one per night You can do one in the evening after having let the spectrograph cool down and one in the morning to e
33. m 8 6 Chemical composition and metallicity Two stars of same class and same type have a different history a different genealogy We note Z the metallicity or the ratio of atom different than hydrogen and helium One can position each star on a 3 dimension HR Z diagram temperature luminosity and metallicity We classify sars in two populations 1 Population I stars rich in metal ie non hydrogen or helium atoms often second or third generation stars Part of their matter has been created during the explosion of a supernova Our Sun and matter that constitutes us is a good exemple 2 Population II stars poor in metal very old We can find them typically in globular clusters ci LSshelyak NEUI LISA User Guide DC0012A 28 67 8 7 Doppler Effect Doppler effect explained by Christian Doppler in 1842 is a wavelength shift between emitted light and received light when object and observer are moving from each other If they approach themselves shift is toward blue if they are moving away it is toward the red such as the redshift of galaxies Doppler effect allows to measure radial velocity rotational speed and expansion speed It is the key to study binary systems and it has been the key of the discovery of the first exoplanet in 1995 Line profiles are also modified by wave movement at the surface of stars Asterosismology allow to better understand the internal structure of stars Even if one can t see the star
34. move the big screws one per door and slide them gently towards the camera C INSTRUMENTS LISA Es User Guide a DCO012A 14 67 Untighten the white plastic screw on the side This screw is to lock the main optics in position You can now move the LISA main optics with one finger in each door opening Take regular images with the camera and rotate the lense in the direction that improves the focus Bright lines must become thiner and thiner brighter and brighter Once you have found the approximate position for the lense optimal focus take some time to fine tune it The most efficient way is to measure the Full Width Mid Height FWMH and make it the smaller possible You can calculate the theoritical FWHM of lines for your setup The line in the image is the image of the slit multiplied per 0 68 Optimal width is to have lines of about 2 5 pixels wide Let s take an example in our configuration the slit is 35um The CCD pixels are 9um large The slit image will be 35 x 0 68 23 7um which is 2 6 pixels 23 7 9 This means that in the optimal focusing position the FWHM should be about 2 6 pixels wide In practice this optimal case will be hard to get a FWHM less than 3 pixels 25 more than ideal is a good result To get to this resolution the accuracy required on the lense rotation is about 1 10th of a turn 1 10mm Tighten the plastic screw main lense locking Do not remove the CCD camera from
35. n be used to do preprocessing and basic geometry correction IRIS is a free software written by Christian Buil that includes lot of spectroscopy specific functions Its limitation is around unsigned 16bits files as IRIS works with signed 16bits files AudeLA is a powerful open source ie free package that includes telescope control and autoguiding on a star but also on a slit and all functions to process your spectra RSpec is a spectroscopy dedicated software which is limited in terms of functionnality but works real time making spectroscopy very fun It is a great software for educational purposes or to discover spectroscopy VisualSpec is a free software dedicated to spectroscopy It doesn t preprocess files but you can use AudeLA for this but you can extract profile and wavelength calibrate your spectra Most importantly VisualSpec does include a lot of functions to analyse your spectra either manually or through a batch VisualSpec includes an extensive user documentation which you can easily refere to Note While several paths can reach the same goal we recommend you to use the RLhires all in one package to extract your spectra and VisualSpec to analyse them IRIS http astrosurf com buil iris RLhires http astrosurf com buil rlhires tuto1 htm VisualSpec http www astrosurf com vdesnoux AudeLA http audela org dokuwiki doku php id fr start SpcAudace AudeLA module http bmauclaire free fr spcaudace LSshelyak NEUI
36. nsure calibration didn t change during the night If you take only one calibration set it is recommended to do it in the middle of the night Whatever your process is use the same one consistantly for all your observing sessions Calibration set consists of two calibration series A Flat spectra which is a spectrum a the tungsten lamp in front of the slit or the spectrograph put a diffuse paper in front of your telescope and a 200W hallogen lamp for exemple Of course you can also use the tungsten inside the optional calibration unit This flat will be mainly used to get high frequencies pixel non uniform response caused by dust on the CCD front glass for exemple or overall instrumentation vigneting ci LSshelyak NEUI LISA User Guide DC0012A 21 67 Make sure to take a long serie about 15 exposures of flat spectra as the processing will divide your spectra by this flat The signal has to be as high as possible without any saturation B Wavelength calibration spectrum is an emission spectrum from a lamp We usually use a Neon for such calibration knowing that there are not a lot of blue lines in such lamps You can also use Argon lamps if you have one of those they can sometimes be found in home lamp shops Take three exposures each time to do a median of them and remove any single exposure defect Here are some exemple of calibration including the Neon hich is within the optional calibration unit Neon LR Decorative
37. of the CCD chip center Let s take an example We use a QSI583 camera 3326x2504 pixels 5 4um The CCD center is at pixel 1663 3326 2 2 716mm is 503 pixels 2716 5 4 Then ref line must be at pixel 1663 503 2166 Here is the positionning you must have when grating angle is properly tuned we ve shown here several common CCD chips EE E SR KAF400 768 x 512 pix 6 91 x 4 6 mm pixels 9 pm KAF1600 1536 x 1024 pix 13 8 x 9 2 mm pixels 9 um KAF3200 2184 x 1472 pix 14 85 x 10 26 mm pixels 6 8 um QS1583 KAF8300 3326 x 2504 pix 17 96 x 13 52 mm pixels 5 4 um EOS 50D 4572 x 3168 pix 22 3 x 14 9 mm pixels 4 7 um LISA User Guide DC0012A 59 67 INSTRUMENTS B Configuration INFRARED This configuration must be detailed soon 11 6 Appendix F Tuning the calibration screen The calibration screen is made to enlight the slit with calibration light sent through the calibration window The position of the calibration screen is tunable by moving the electro magnet which control it If the calibration screen is not properly tuned the calibration spectra will not be perfectly homogeneous transversal direction You can see the calibration screen from the to opening of the spectrograph telescope light entrance If you activate the screen plug a 12V power supply in the connector you ll see the calibration screen moving from release to active position
38. ook covers in general all subjects including astrophysics All STRON lt LSshelyak LISA User Guide DC0012A ie The stars their structure and evolution R J Tayler ed The Wykeham Science Series for schoold and universities j 4 Almost an historical book to place into context Fhelgak 4h THE WYKEHAM SCIENCE SERIES SED toc schools and uriversities NASA CNRS monographs by spectral types In 1980 s NASA amp CNRS published a monograph series on nonthermal phenomena in stellar atmospheres Those make an excellent overview of the science knowledge of the stars at that time Introduction is translated in french O stars and Wolf Rayet stars B stars with and without emission lines NASA SP 456 Anne B Underhill A type stars FGK stars and T Tauri stars M type stars NASA SP 492 Johnson lt LSshelyak LISA User Guide DC0012A ie Early Type stars books Pulsation Rotation and Mass Loss in Early type Stars Balona Henrichs Lecontel __ Graduate level compilation of articles of the International Astronomical Union Symposium 162 Articles can also be found on Abstract Data Services im Early emission line stars C R Kitchin ed Adam Hilger Ltd Bristol Book to place into context for collectors tars with the B e phenomenon Michaela Kraus amp Anatoly S Miroshnichenko Graduate level but with excellent general overview of B e in first articles Articles
39. pe is a Planck curve whose maximum is directly linked to the effective temperature of the surface stellar atmosphere this is the Wien law 10000K vt 3000K 3000K 5500 6500 7500 8500 Continuous spectra of several black bodies Our Sun has an effective surface temperature around 6000K visible stars to us have temperature between 3000K and 30000K Stars are classified based on their temperature with historical letters O B A F G K M Stars with O type are the hottest while M type are the coolest We memorize this sequence with the famous Oh Be A Fine Girl Guy Kiss Me Types R S and N have been added later one Right Now Sweetheart Annie Jump Cannon was one of the most famous assistant of Edward Charles Pickering in Harvard She was an expert in stellar classification For the Henry Drapper catalog she classified more than 300000 stars an example of productivity 8 5 Spectral class If the spectral type is a characteristic of the surface temperature a more precise classification should take into account their luminosity In Yerkes William Morgan Philip Keenan and Edith Kellman MMK established a classification I to V which takes into account the shape of some absoprtion lines characteristics of gravity forces Class I stars are super giants while class V like the Sun are sub giants stars Astrophysists position stars on a graph based on their temperature and luminosity This is the Hertzsprung Russell diagra
40. pointing and graduate level book on RR Lyrae stars Cataclysmic Variables Stars Brian Warner ed Cambridge Astrophysics Series 28 Excellent but graduate level book on the subject F ka TT Protostars and planets V Bo Reipurth David Jewitt amp Klaus Keil g Articles can also be found on Abstract Data Services lt LSshelyak LISA User Guide DCO012A 41 67 Tenth anniversary of 51 Peg b eee UC Arnold Francois Bouchy amp Claire Moutou ed Observatoire de Haute D Provence Frontier Group 2005 Une bonne revue des connaissances et des questionnements dix ans apres Bla d couverte de la premi re exoplan te 51 Peg b Books on Physics Atoms Stars and Nebulae Lawrence H Aller Atomic spectra and atomic structure seiGerhard Herzberg Gerhard ter Excellent book on how it works at atomic level The spectra and structures of simple free radicals an introduction Lsato molecular spectroscopy mace Oerhard Herzberg This book is the follow up of Atomic spectra and atomic structure and covers a more complex subject how spectroscopic lines are formed in molecular structures Miscellaneous books Teaching of Astronomy si 7 AU Colloquium 105 3 Cover most aspect of education and teaching in astronomy lt LSshelyak LISA User Guide DCO012A 42 67 Extreme Stars ame B Kaler ed Cambridge Exem James Kaler writing makes it a general public
41. rsion kit Remove carefully the protection cover by untighting the screw CHRIS Put the cover on the VIS grating holder tighten the screw Put the lever on the IR grating 2 screws Respect the direction of the lever like on the picture 4 eee EN j ry a Put the IR grating in place onto the chassis Put the lever at the approximate position given on the picture Close the LISA see appendix B Put the VIS grating holder in a safe place B Installing the blocking filter Remove the slit from the LISA two screws INSTRUMENTS LSshelyak LISA User Guide DCO012A 55 67 Install the blocking filter on the opposite side of the slit Take care to not damage the slit by itself don t put it on the table en the part in hand Pid we F2 pr i I TT ji LA i Fe M H E Put 2 screws with plastic rings on must be fixed but not damaged Reinstall the slit in the LISA C Changing the CCD camera spacer Shelyak IMS TRUPENTS Ez y FL 5 Pe rf ee j P F each side of the filter Tighten them sligthly the filter FT Remove 4 screws from the CCD camera holder You ll get the CCD camera holder by itself threaded part and the spacer Install the inclined spacer on the LISA with 4 screws M4x10mm The orientation must be as on the picture LISA User Guide DCO012A 56 67 D Tuning Once all abo
42. slit and its center Once you have found the optimal position hole or center of the slit in the middle of the guiding image tighten back the two external screws Your LISA guiding mirror is tuned INSTRUMENTS LISA User Guide a DCOO12A 64 67 11 8 Appendix H Focusing amp aligning the collimator The collimator tuning focus and alignment is made in our factory before shipping But you can for any reason want to check or tune it again this section explains how to do it Be careful this is a complex operation which must be done only by experienced user To work in good conditions the grating must be enlighted by a parallel light beam This parallel beam is made thanks to the collimator doublet the doublet must be perfectly focused on the slit To make this operation you must use the tuning slit provided as an option by Shelyak Instruments with a 19u hole in the center Focusing the doublet can be done this way Open the LISA see appendix B Remove the grating holder and put it in a safe place see appendix C Use any optical device focused at the infinite It can be a telescope finder used visually or the guiding camera with lense focused at the infinite this is our practice at Shelyak Instruments Look with this optical device through the collimator doublet towards the main mirror Align it properly to see the slit Untighten the doublet screw Rotate the doublet until
43. start the opening you can slide it between two sides Take care to not damage the painting The LISA is now open Be very careful with the optical elements they are very fragile Think to protect them against dust and finger prints INSTRUMENTS LISA User Guide DCO012A 50 67 CLOSING Of course closing the LISA is exactly the same operation in the opposite order Take the Chassis in left hand and the Cover in right hand Catch them by putting the thumb in door opening Present them with precision well parrallelly fitting Engage the Telescope plate and the CCD plate first check they are exactly at the right position Slide both sides together until the box is closed Check all area is properly positionned all C Shelyak LISA User Guide DCO012A 51 67 around the spectrograph Put the plastic screw main lense lock Put 2 screws M4x10mm on the telescope plate side Put 2 screws M3x10mm on the LISA side C INSTRUMENTS LISA Es User Guide a DCOO12A 52 67 Tighten all these 6 screws At the end tighten all nine screws around the spectrograph Finally close the side doors p uel Your LISA is back ready for observation Depending on what you changed when you opened the instrument you may have to re tune some parts of the instrument 11 3 Appendix C Switching from VIS to IR The LISA can be configured in two modes V
44. strophysics D Tome 1 basic stellar observations and data Tome 2 stellar atmosphere Tome 3 stellar structure and evolution Introduction to modern Astrophysics Bradley W Carroll amp Dale A Ostlie A thick but excellent reference book Almost every aspects of astrophysics lare covered and the book includes tons of exercises unfortunatly without answers A must have in your library Astrophysics of emission line stars eee KOgure amp Leung ed Springer 2009 MS A new and very detailed book on all emission line stars Wolf Rayet Be T alles Tauri Includes several tables with key targets for our spectrographs An excellent book lt LSshelyak LISA User Guide DCO012A 34 67 ree Stellar evolution and nucleosynthesis 7 eaSean G Ryan Andrew J Norton ed Cambridge Graduate level book but an excellent course support which includes mlexercises and solutions eaStars and stellar evolution aig PAK S de Boer amp W Seggewiss ed EDP 2 Overview of the subject Interesting mainly as first book on stellar See astrophysics m Astrophysics is easy an introduction for the amateur astronomer Mike Inglis MPart of Springer serie on Astrophysics This book lack of practical very hard mato find a spectrum in the book but the explanations are crystal clear and this by itself makes this book valuable Observer s guide to Stellar Evolution gam Mike Ing
45. surface visually their light brings us a message full of learning 8 8 Conclusion Spectrography is like archeology or a criminal case study With clues included in spectra the astrophysist tries to go back to the root of the phenomena Almost all professional observations are done today in spectrography Large telescope are equiped with powerful spectrographs to analyse large spectral domain and several targets at once But now spectrography is evolving within the amateur astronomy community High resolution spectrography the message from the stars is now accessible to you with your Lhires III LSshelyak NEUI LISA User Guide DC0012A 29 67 9 Troubleshooting Support For any issue with your Lhires III contact us at Phone 33 476 41 36 81 Mobile 33 689 92 74 23 eMail contact shelyak com Web http www shelyak com Address Les Roussets 38420 Revel France You can also subscribe to the Spectro L internet list where you will find the support of other Lhires ITI users http groups yahoo com group spectro l And regularly look on our website for project update and announcement of technical week ends those are the best way to learn and develop yourself in this wide field that is spectrography LISA User Guide DCO012A 30 67 TNSTRUMENTS 10 References This is only a few of references that we find useful If you know others do not hesitate to drop us a note contact shelyak com so it can be added in
46. t you are already familiar with spectroscopy basics and that you are able to control your telescope and your CCD camera We start with a presentation of the instrument then we ll describe how to prepare it and and we ll finish with its using in the field You ll find also in appendix how to tune all the parts of the instrument as it has been done in the factory LISA can be used in two different configurations the standard one is VISIBLE mode This is the one we describe in this document The other one is INFRA RED You will find in appendix the differences between two configurations and how to switch from one to another this must be done by experienced user only Keep in mind that the spectrograph must be tuned and prepared during daylight in a room do not go straight towards the telescope and wait for night Starting in spectroscopy can be impressive since there are several elements to put under control But thanks to this guide you will see that none of them is very complex and just some rigour is required to make things working together We hope that you will enjoy spectroscopy with LISA Join the increasing Shelyak Instruments users and amateur spectroscopist community on Spectro L http groups yahoo com group spectro l to keep us informed of your progress and results and to look for new projects or observing campaigns But most importantly enjoy spectrography Olivier Thizy olivier thizy shelyak com Francois Cochard fr
47. the LISA side lt LSshelyak LISA User Guide DC0012A 46 67 Tighten the screw You can test the module is properly working Connect a 12V power supply in one of the calibration module connector Switch on amp off the matching button ie flat or neon You must hear the electro magnet activation and see the light in the spectro the flat light is easy to see the neon one is fainter If you want to use the calibration light remotely connect a controlled 12V power supply in each connector of the calibration module and switch the buttons on If for any reason you decide not to use the calibration module anymore don t forget to put back the calibration window cover and the M4 screw to prevent any light leakage into the spectrograph INSTRUMENTS LISA User Guide DC0012A 47 67 11 2 Appendix B Opening closing the LISA In some specific conditions you can have to open the LISA This operation must be done only if you exactly know what you re doing After such an operation you could have to check the tuning is still Ok and probably to refine the tuning The LISA is made of two major assemblies The chassis and the cover The chassis embbeds all optical elements of the spectrograph slit main mirror collimator grating camera lense This is done to make possible to tune the instrument when it is opened The covers contains all elements for guiding and calibration You can see that Chassis an
48. the LISA until you install it on the telescope If you have to remove the camera from the LISA you will have to re focus it fine tuning only 5 3 Grating angle The grating angle have been tuned in our factory before shipment This tuning is very sensitive to get the best wavelength bandwidth amp quality The simplest way to check this point is to take a spectrum of the Neon with camibration module or with external Neon lamp Focus carefully the spectrum and adjust the exposure time to prevent any saturation You should have something very close to this for this picture we ve used the tuning slit with 19um hole and a QSI583 camera lt LSshelyak LISA User Guide DCO012A 15 67 du A l LL mi I Il In this Neon spectrum you can see the special pattern 5 lines around Ha 6563A TPMT TEN a If the spectrum is not positionned conformly to this image see in Appendix E how to correct this this must be done by an experienced user LSshelyak LISA User Guide DC0012A 16 67 AL AIRIS KAF400 768 x 512 pix 6 91 x 4 6 mm pixels 9 um KAF 1600 1536 x 1024 pix 13 8 x 9 2 mm pixels 9 um KAF3200 2184 x 1472 pix 14 85 x 10 26 mm pixels 6 8 um QSI583 KAF8300 3326 x 2504 pix 17 96 x 13 52 mm pixels 5 4 um EOS 50D 4572 x 3168 pix 22 3 x 14 9 mm pixels 4 7 um Depending on your CCD chip the positionning of the spectrum should be close to this one 5 4 Checking the calibration
49. tion we consider that you already know how to use and control your CCD camera We use the example of a QSI camera 5 2 1 Installation Mount your CCD camera on the LISA spectrograph with the proper adaptor to put the CCD plane at the nominal position 54 85mm from flat face of T mount Put the camera ring on the camera lt LSshelyak LISA User Guide DCO012A 13 67 Put the LISA ring on the LISA and assemble the camera on the LISA Make it right parallel to the LISA body the long side of the CCD chip must be parallel to the height of the LISA and tighten securely the three screws Switch on your camera and your acquisition setup PC acquisition software Remove the cap from the telescope adaptor to let natural light enter in the spectrograph Take an image with 1 second exposure You should get your very first spectrum Based on this first picture adapt the exposure time to prevent any saturation few seconds is usually enough If necessary fine tune the camera orientation in order to have a spectrum perfectly horizontal in the image 5 2 2 Focus The spectrum is probably not well focused If possible use from now on an energy saver lamp it has some very bright an thin lines that will be very useful to tune the instrument You can also use any calibration lamp if you have one Of course if you have the integrated calibration module switch on the Neon lamp Open both doors on LISA sides just re
50. uning arm Figure 2 LISA main elements Figure 3 describes in detail the light path for both spectrograph and guiding section Light beams cones and cylinders are sketched Figure 3 LISA light path LISA User Guide DCO012A 6 67 TIMHSTRUPENTS The star light is focused by the telescope 1 goes through the slit 2 is reflected by the mirror 3 amp 4 is transformed in a parallel beam 5 by the collimator Then it is diffracted 6 by the grating goes through the objective lense and converges 7 towards the CCD sensor 8 For guiding section all light coming from telescope 1 which does not pass through the slit 2 is reflected towards the guiding mirror 9 sent to the guiding optics 10 and refocused 11 to the guding camera sensor 12 The focal length of the collimator is 130mm The focal length of the camera lense is 88mm This means that the slit image will be multiplied by 88 130 0 68 on the CCD The focal length for both guiding doublets are the same 75mm Then the ratio between object in telescope focale plane and image in guiding camera is 1 1 3 2 Calibrating the spectra Calibration the spectra wavelength is necessary for scientific usage of your data as well as flat spectra to correct the instrumental response curve of the whole instrumentation The LISA spectrograph includes some features to make these calibration easy and precise A calibration window is available on LISA s
51. ve modifications are finished you must tune the grating angle This is described in detail in Appendix E 11 4 Appendix D Switching from IR to VIS The conversion form IR configuration mode back to VIS mode is obviously the reverse operation of above section Refer to it for detailed operations Generally speaking the operations consist in Open The LISA and replace IR grating holder by the VIS grating Remove the blocking IR filter if you forget it you ll see only the deep red part of the spectrum Remove the inclined CCD camera spacer and replace it with the parallel spacer 11 5 Appendix E Tuning the grating angle The grating angle is key to get the best spectrum quality in LISA This is a sensitive tuning which must be done by an experienced user only To make this tuning you must put the LISA on a stable surface large table for instance and install the CCD acquisition camera You must have the full setup operatonal to take some spectra using calibration light neon energy saving lamp Hg if you don t have such lamp use the solar spectrum but this is harder to measure lines width This tuning is much more easy to do with a tuning slit provided by Shelyak Instruments this is a slit with one hole 19um and a partial slit 19um on each side The advantage is that each spectrum line taken with this slit is a point and it is easy to measure precisely the FWMH to eveluate the focus range c a IN
52. we process in Shelyak Instruments factory before shipping your LISA Collimator doublet focusing and aligning see appendix H Close the LISA see appendix B Tune the grating angle see appendix E Aligning the guiding mirror see appendix G Tuning the calibration screen see appendix F lt LSshelyak LISA User Guide DCO012A ire
53. which star you can see those element on Work in pair with The Classification of Stars The Classification of Stars Carlos Jaschek amp Mercedes Jaschek his book lists per spectral type which spectral line element to look for Work in pair with The behavior of chemical elements in Stars Some may prefere a more recent book Spectral Classification from Richard Gray pectroscopic atlas of bright stars ack Martin Part of Springer serie on Astrophysics Made with a low resolution grating several spectra of bright stars to compare hire ape ic Atlas of ewestarlight es Keith Robinson XxX Cc Part of Springer serie on Astrophysics Mee stronomical Spectroscopy AUS onathan Tennyson Professional book usefull for spectrograph builders sometimes complex for amateurs PRACTICAL AMATEUR SPECTROSCOPY mea AA LISA User Guide DCO012A Practical Amateur Spectroscopy Stephen F Tonkin with several authors Part of Springer serie on Astrophysics One of the first of the serie published when very few commercial spectrographs were available so a large part is dedicated to home made instruments Astrophysics books EFN Astrophysics atmospheres of the Sun and Stars Lawrence H Aller ed The Ronald Press Company OCR A little bit old book now Sun and Stars Introduction to Stellar Astrophysics T1 3 Erika Bohm Vitense W ae A three book course on stellar a
54. ylight sise sseeeeeeeneensss 25 6 1 1 Mounting the LISA on the telescope ccccce cece eeeee eee eeeeeneeeeeees 25 6 1 2 Check Fine tune adjustments focus guiding focus LISA acquisition OCTO OS COR a rerpunerwaneesrwigete nesaunaesgeamevaasuaasaneuaeaiess 25 6 2 Standard acquisition procedure sise ssnss ss en ennaeneeeeeeeseeeeeaunnnnteseas 25 6 2 1 CCD master il QC Sabana aan na anne ae ain uen 25 622 2 Calo PA On ANO a a ee ee cians 26 6 2 3 Object AM ae eraa as disaa aie dosnue is aa ee oui ce on buo aue 27 6 2 4 Reference star SPECCrUM c ccccccsenevecucuencucvecectensuntenucueneureueenausennns 28 A FTOC S IN ee EE E de ee Se et 28 PPS OS E ER 28 Pie GOOM IEEE D ee 28 7 5 REMOVE DOCROTOUNO Sa ns tienne a ne na ae a di Caen 28 7 COMMING SOE CU a nada das dan oc Gas ten de co Da ete de D ie to io 28 Pea Gus end le ES 57210 16 PROPRES 29 7 0 WeVele NO Cabo ae a ae ae ad do nn ous 29 77 INSTTUMEN TS TES DONS danses denses en Dia dane nes ne D a 29 Ne es 30 S SPECTOSCOPY IACTOMICUIONE RS ae ados aude at ea aa eu ae D de nca a D 0 31 8 1 Inthe DECIDNIN san ane ca aa dei en on uen a an Na ou os 31 8 2 Different types of SD CLEA 4 sasaessss sas ms sassauasss dass ds stansuaacsdass ss s anmuenssmamansssentanaie cuis 31l D ME S O NOM arae ENEE EA 32 8 4 Effective temperature and spectral typeS s ssssssrssresrrsrrsrrsrrnrrnrnrenerenrnrnrernrrrerrrerrnne 33 eege 8 618 fs CSS E E AE AN E N E
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