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Northern Prairie Star Party Black Nugget Lake September 15, 2012

Northern Prairie Star Party Black Nugget Lake September 15, 2012. Brian Martin The King’s University College. Three Fundamental “Sciences”. Measuring “Distance”, Position & “Scale”  Astrometry Measuring Brightness and Intensity  Photometry Measuring “Colour”  Spectroscopy.

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Northern Prairie Star Party Black Nugget Lake September 15, 2012

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  1. Northern Prairie Star Party Black Nugget Lake September 15, 2012 Brian Martin The King’s University College

  2. Three Fundamental “Sciences” • Measuring “Distance”, Position & “Scale”  Astrometry • Measuring Brightness and Intensity  Photometry • Measuring “Colour”  Spectroscopy Exciting science that you can do from the back yard!

  3. Astrometry August 29, 2012 H-alpha filter 0.001 s exposure ED80 Atik 314L+ camera TKUCO How big are the lunar features in this image?

  4. Some Math … S R q • The Small Angle Formula Rq* = S where: • R = distance from object • q = angle that the object subtends in the sky • S = distance across the object * Angle in radians

  5. The Scale of Your Telescope • Scale in (seconds of arc)/mm found by: • In the previous image a ED80 telescope was used so the scale is (206265)/(600 mm) = 343.8 “/mm • The Atik 314L+ has 6.45 mm pixels, so each pixel has a scale of 342.8”/mm × 0.00645mm/px = 2.22 “/px when used with the ED80 • By measuring the number of pixels you can measure the angle that an object or feature subtends

  6. Distance = 0.002524 AU 304 px = 1236 km 850 px = 3457 km (0.5% error)

  7. Some other images… • Capuanus Crater: • December 26,2009 • C14, f/11 • Imaging source DMK2104 • 2000 frames • Distance = 0.002523 AU • Scale = 0.20”/px = 0.37 km/px

  8. Apennines (Eratsothenes, Archimedes) • March 1, 2012 • C14, f/7 • Atik 314L+ • 20 frames (0.005 s) • Scale = 0.52”/px • Distance = 0.00262 AU

  9. Jupiter • November 5, 2011 • Distance = 3.98101 AU • C14, f/11 • Imaging Source DMK2104 • LRGB (~2000 frames each) • Scale = 0.29”/px = 837 km/px 159 px = 133 000 km 170 px =142 000 km Oblateness = (142 -133)/142 = 6.3%

  10. M57 • August 26, 2011 • C14 f/7 • ST7E • LRGB • Distance = 2300 ly • Scale 1.49”/px = 0.017 ly/px 160 px = 2.7 ly

  11. M15 • August 21, 2011 • C14 f/7 • ST7E • LRGB • Distance = 33 Kly • Scale 1.49”/px = 0.238 ly/px 534 px = 127 ly

  12. Photometry – Measuring Changes in Brightness • Intrinsic Variables • d Scuti • SX Phe • Novae and Supernovae • Cataclysmic Variables

  13. Capable of doing excellent science! Modest cost (< $2000) Excellent software support Monochrome with no anti-blooming is preferred Pixel size should be carefully matched to image scale – need to oversample Capable of milli-magnitude precision photometry Consumer grade CCD cameras… Atik 314L+ SBIG ST7E

  14. SX Phoenicis Variables • BL Camelopardalis • Average mag 13.1 • Period • 0.0389d • 56 minutes – this is an exciting system to watch!! 40 s integration, C14 f/7 ST7E camera – KAF400 detector

  15. The Light-Curve… November 9, 2009 BL Cam Teff 7730 K Age ~4Ga Metal poor Period shows a Small change over time! November 9, 2009, s (C2-C1) = 0.007 mag

  16. DY Pegasi … A Nice Intro to SX Phe • A great star! • Bright (m = 10.3) • Excellent Check and Comparison stars • Well placed for fall observations Data collected with 8” Newtonian and SpectraSource Lynxx (TC211)

  17. Cataclysmic Variable Stars • Binary stars that are exchanging mass • One of the stars is compact • Hot spot forms on accetion disk • Accretion disk around compact star produces variability • A rewarding study for amateurs!

  18. Two exemplar CVs… TKUCO 120 s image 0.32 f/4.8 • DW Uma • Period (d) 0.136606 • Mag 14 - 18

  19. TKUCO 60 s image 0.32 f/4.8 • GK Persei • Period (d) 1.996803 d • Mag 11.5 - ?

  20. Other Photometric Delights! • Novae and Supernovae • Algol systems • Asteroids NGC 6946 30s exposure September 29, 2004 SN 2004ET 0.32 f/4.8 Newtonian ST7E camera

  21. Spectroscopy • Broad and Narrow band filter imaging • Low Resolution Spectroscopy • Medium – High Resolution Spectroscopy

  22. Broadband Colour Imaging L R M27 LRGB, August 2011, C14 f/7 ST7E G B

  23. Narrow Band Imaging • Ha • Hb • SII • OIII

  24. Ha S II O III C14 f/7Atik 314L+ March 1, 2012

  25. LRGB image of central region of M51 C14 f/7 ST7E L filter with Ha overlay showing star forming regions along spiral arms C14 f/7 Atik 314L+

  26. Stellar Spectra (Low R) • Remarkably easy to do – even with modest equipment! • Small telescope w/wo tracking • CCD or DSLR • Rainbow Optics or Star Analyzer grating • Introduces a fascinating new direction for amateurs

  27. Some samples… (trailed images with Atik 314L+, Orion 80 mm ED)

  28. Note Deneb’s narrow lines! Vega, Teff = 9600 K Altair, Teff = 6900 K – 8500 K Altair is a very fast rotator and is squished like a football! Hotter at the poles by about 20% Ca II line

  29. Other Interesting Stars… Which is these is the hottest star? T = 7 100 K F2 T = 31 000 K B0.5e T = 8 400 K A5 Be Star with disk

  30. Planetary Nebulae The “Eskimo” – NGC 2392 C14 f/7 10 minutes April 21, 2011 The reason nebula filters work!

  31. Measuring the Expansion of the Universe! 3C273 C14 f/7 60 minutes ST7E April 5, 2011 Zaverage = 0.159

  32. Universal Expansion • What does z = 0.159 mean? • Apparent recessional velocity is 0.159C = 47 700 km/s! • Hubble expansion law: • Hubble’s constant H = 70 km/s/Mpc • R = 681 Mpc = 2.2 billion light years!

  33. Medium/High Resolution Spectroscopy • For more advanced work • Requires robust mount and tracking • Need as much aperture as possible • BUT – still well within the reach of advanced amateurs and astronomy clubs!

  34. The L200 Littrow Configuration • Can resolve to about 1 A (R = 3000) • Built from a kit, cost ~$1000 • Capable of useful research on Be, WR and Algol type stars (and much more!)

  35. The Solar Spectrum ST7E on C14

  36. Altair

  37. Homebrew for under $200! And it Works!

  38. The Magnesium Triplet… R > 5000!

  39. Some References… • Christian Buil - http://www.astrosurf.com/buil/ • Tom Field - RealTimeSpectroscopy (RSPEC) http://www.rspec-astro.com • Rainbow Optics Spectroscopes http://www.starspectroscope.com/ • Center for Backyard Astrophysics (CBA) http://cbastro.org/

  40. Thank you – Questions?

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