This is a crop of the resulting stacking of 36x30s + 2x360s subframes taken this month in two different sessions. The area showed corresponds to M101 and surroundings (in Ursa Major), in which we find other 2 galaxies NGC 5474 and NGC 5477. Below, I have added a DSS2 image of the are for comparison. My stars are blobs, meanwhile DSS2 are pinpoint. On the other hand, I use to lose star colours specially in the brightest ones , when postprocessing and stretching histogram. Maybe some day I will learn how to fix all these errors …
Archive for Ursa Major
M101 with 300mm telephoto lens
Posted in Astrophotography with tags Astronomy, Canon EOS 450D, Deep sky, DeepSkyStacker, EQ6 equatorial mount, M101, NGC 5474, NGC 5477, Rebel XTi, Reflex, Tamron 300mm, Ursa Major on 2010/04/25 by computerphysicslabMizar & Alcor
Posted in Astrophotography with tags afocal, Alcor, Big Dipper, Casio Exilim EX-Z80, dobsonian reflector, double star, Meade Lightbridge 16", Mizar, no tracking, shift-and-add, Sidus Ludoviciana, Ursa Major on 2009/03/24 by computerphysicslabMizar and Alcor are probably the most well known double star in the sky. Located in Ursa Major,it is very easy to separate Mizar from Alcor, even with the unaided eye.
Sidus Ludoviciana is the faint star between Mizar and Alcor. Mizar is the brightest one, which in fact is a binary system: Mizar A & B, with an angular separation of 14 arcseconds.
Photo taken with the dobsonian reflector Meade Lightbridge 16″, using afocal eyepiece proyection. Here we see 222 shots of 0.5 seconds of exposure stacked. No tracking, shift-and-add method.