>Betelgeuse grand minimum is not that grand
For a few months from now Betelgeuse (Alpha Orion) dim so much, that it looks as bright as the stars in the Orion belt. This is not so disturbing and does not mean that cataclysmic events are happening with it. This brightness lost is mostly in the visual spectrum. The star is still shining as the brightest one in the constellation, when looked into the inferred spectrum. Below is comparison of the Orion constellation seen in visible and inferred light. In visible Rigel (Beta Orion) seems to be the brightest star. However in Inferred, Betelgeuse outshines it quite a lot.
We all hope that this star will explode in near future, so we will have some nice target for shots and research. For our luck it is just far enough not to cause any troubles :)
Orion in Infrared:
Betelgeuse spectrum. White is infrared, Orange is Halpha.
Recently I got one very good lens the Asahi Takumar 135mm 1:2.5. This is fast telephoto lens and from my point of view a good lens should be with aperture from 1:1,2 to 1:2,8.
Moon at 45% illumination and 70x magnification. With aperture of 200mm,14,1 stops dynamic range, color depth of 23.7 bits at this image there are slight color variation on the moon surface that reveals it’s structure.
This is the beginning of my research on how dark the sky could be and what is benefit of a dark sky for astrophotography. I was inspired from those 2 sites. First one presents mathematical model of how dark the sky is.
You can find my last DSLR Astrophotography article in Bulgarian at page 76. I am sharing my last findings for this publication, Specially written for the Institute of Astronomy.
Satellites, cosmic trash or UFOs, the moving spots are everywhere on the sky. Typical satellite behavior is to reflect sun light. It should be yellow or white and could fade and shine due to its rotation.