The cool things you catch while testing

May 14, 2021

I haven't used the color rig this season, and I was capturing batches of subframes across the sky, mainly to test out focusing. I polar-aligned reasonably well, but didn't guide with these subs. I came away with a bunch of starfield shots, and stacked a couple batches.

The first is the massive blue-white B-type star in the center is Gamma Lyrae or Sulafat from the Arabic السلحفاة al-sulḥafāt "turtle", 漸台三 Jiāntāisān in Chinese astronomy, meaning the Third Star of Clepsydra Terrace. Sulafat is 15 times the sun's size, a little over 600 lightyears away, and it's burning brightly through its main sequence and out the other side. 

What's cool is if you right-click this image, open in a new tab, and expand to full size, you can see M57, the Ring Nebula, is there in color middle top of the image.

For this set of subs I centered on NGC 5746, the tiny sliver of a barred spiral galaxy in the center. The bright star below it is 109 Virginis in the constellation Virgo. What's crazy about this shot it there at least twenty other galaxies in this frame--probably a lot more that just show up as pinpoints of light.