The document discusses the development of a Littrow spectrograph and its advantages over a classical spectrograph. It describes using the Littrow configuration to enable amateur astronomers to conduct research through spectroscopy. Details are provided on constructing the spectrograph, aligning it, and obtaining spectra of various astronomical objects using a DSLR camera mounted to a telescope.

1. Developing a Littrow Spectrograph Mary Masterman Westmoore High School & University of Oklahoma

2. Purpose of Littrow Glass Study Spectroscopic Binary Stars Study Zeeman Splitting Popularize spectroscopy by enabling amateur research Study Vibrational Spectroscopy through Raman Effect (applications to planetary science)

3. The Double Slit Experiment

4. Why Does This Happen?

6. What Happens

7. http://www.src.wits.ac.za/pages/teaching/Connell/phys284/2005/lecture-02/lecture_02/img21.png What Happens

8. Graph from Scott Hesser. Photo from http://www.thespectroscopynet.com/Educational/Diffraction.htm . -1st -2nd 1st 2nd The Double-Slit Experiment With Different Colors

9. 1st Order -1st Order Transmission Grating White Light 0th Order Camera (or Screen)

10. Reflection Grating

11. 2004 38 ° classical spectrograph

12. 38 ˚ Classical Spectrograph Disadvantages: Long, heavy, stuck out from telescope Low Resolution: longer lens needed Solution: Try Littrow Configuration Theory : Christian Buil, France

13. New Spectrograph: 2006

14. Light path: side view

15. Light Path: top section

17. Fabricating Body

18. Body/ Mirror

19. Grating Holder

20. Adjustable Slit

21. Camera Mount

22. Aligning Spectrograph

23. Using on Telescope

24. Wavelength (Angstroms) Intensity (ADUs) Solar spectrum w/ Fraunhoffer lines Camera: Canon Rebel DSLR (no Telescope)

25. M42 Nebula Neon calibration spectrum SII NII H α NII

26. 0 th Order- center image on slit M57 30cm f/10 telescope 60 sec exposure

27. M57 Spectrum near H  OIII OIII H  Vega H 

28. M57 Spectrum near H  H  NII NII SII SII OI OI

29. Visual Spec Program VSPEC (France) is freeware by Valerie Desnoux. Mercury Lamp Spectrum

30. Crop The Image After acquiring the image, the desired spectrum must be cropped from the raw image.

31. Conclusions A bigger telescope with better polar alignment is neccesary Higher dispersion => Decreased range => Frustrating compared to classical spectrograph Cost $350 – Relatively cheap - Benefit