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!

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

Some Math …  R S The Small Angle Formula R   = S where: R = distance from object  = angle that the object subtends in the sky S = distance across the object * Angle in radians

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) = “/mm The Atik 314L+ has 6.45  m pixels, so each pixel has a scale of 342.8”/mm × mm/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

850 px = 3457 km (0.5% error) 304 px = 1236 km

Some other images… Capuanus Crater: – December 26,2009 – C14, f/11 – Imaging source DMK2104 – 2000 frames – Scale = 0.20”/px – Distance = AU

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

Jupiter – November 5, 2011 – C14, f/11 – Imaging Source DMK2104 – LRGB (~2000 frames each) – Scale = 0.26”/px

M57 – August 26, 2011 – C14 f/7 – ST7E – LRGB – Scale 1.49”/px – Distance = 2300 ly

M15 – August 21, 2011 – C14 f/7 – ST7E – LRGB – Scale 1.49”/px – Distance = 33 Kly

Photometry – Measuring Changes in Brightness Intrinsic Variables –  Scuti – SX Phe Novae and Supernovae Cataclysmic Variables

Consumer grade CCD cameras… 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 Atik 314L+ SBIG ST7E

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

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