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By Keith Schlottman Presented at Texas Star Party 05/16/07.

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Presentation on theme: "By Keith Schlottman Presented at Texas Star Party 05/16/07."— Presentation transcript:

1 By Keith Schlottman Presented at Texas Star Party 05/16/07

2 Have You Ever Used Spectroscopy? Seen a Rainbow? Used a Nebula Filter? Viewed the Sun in H-Alpha? Noticed that Vega is Bluish and Arcturus is Reddish?

3 The Spectrum Tells A Story Stars –Stellar classifications / HR Diagram –Age of star –Surface gravity –Pressure –Surface temperature –Radial velocity –Identify spectroscopic binaries Other Objects –Galactic and Quasar redshifts –Nebular compositions –Comets and Planets

4 Equipment – Visual Spectroscopy Prism CD-ROM Project Star Spectrometer Naked Eye (Rainbows & Moonbows)

5 Equipment – Telescopic Spectrographs More Expensive SBIG SGS LHIRES III Baader DADOS Sivo Scientific Nu-View II Moderately Expensive SBIG DSS-7 Less Expensive DG Spectrum Filters Rainbow Optics Star Spectroscopes Rigel Systems RS-Spectroscope Paton Hawksley Star Analyser Build Your Own

6 Comparison of 4 Spectrographs SBIG SGSSBIG DSS7LHIRES IIIDG1 FILTER COST$4,950$1,595~ $3,000~ $150 GRATING TYPEReflection Transmission GRATING Lines/mm 150 (Low) 600 (High) 100150, 300, 600, 1200, 2400 200, 500, or 1,000 DISPERSION Angst./pixel w/ST-7 4.3 (Low) 1.1 (High) 5.43.0 (Lowest) to 0.12 (Highest) Up to 0.5 RESOLUTION With ST-7 9Å (Low) 2.4Å (High) 16ÅUp to 0.4ÅVaries λ RANGETuneableFixedTuneableFixed GUIDINGInternal or External None or External Separate or External Internal or External BEST FORStars, Nebulae Nebulae, Galaxies Stars Information based on my experience and manufacturer claims, may not be 100% accurate

7 Acquiring Data With the SGS Use CCDSoft Guide on Slit Binning 1x4 Note that images are monochrome!

8 Processing Data Dark Subtract, Median Combine (CCDStack) Rotate if Low-Res Mode (IRIS) Wavelength Calibration (vSpec) Flux Calibration for CCD Response (equivalent to Flat Field)

9 Wavelength Calibration - H Edmund Scientific Lamps are used

10 Spectral Types Spectra taken with The SBIG SGS on a 12 LX-200GPS from my Tucson backyard on October 16 & 17, 2006. RED BLUE

11 Identifying Stellar Composition

12 Emission Nebula The OIII emission lines were thought to be a new element in the early 20 th century, Nebulium.

13 Emission Nebulae

14 Planets

15 Comets

16 Novae

17 Variable Stars

18 Pro-Am Collaborations Amateur spectroscopists were asked to obtain data on this star, which was a target for the COROT satellite.

19 Be Stars

20 Young Stars

21 T Tauri A very young star, still undergoing contraction.

22 Texas Star Party 2007 Blueshifted absorption feature provides a basis for calculating radial velocity of the expanding shell. Preliminary calculation from this data is ~ 200 km/sec. This data was obtained early Monday morning at TSP Upper Field.

23 DG Spectrum Filter Zero and First Order on Main Chip Vega Use Known Lines to Calibrate in vSpec

24 The Easiest Spectrum to Observe – No Equipment Necessary! For more information see:

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