7/3/2021 Trifid Nebula

As noted in an earlier post, Saturday was for dark nebulae. This is the iconic Trifid Nebula that everyone has seen in TV and movies if nowhere else. It has no relationship to those walking sunflowers.It has the name due to the dark lane cutting it into three sections. The Trifid is also known as Messier 20 and the dark lanes are known as Barnard 85. Here we have the smorgasbord of deep sky object types, the red is emission nebula, the blue reflection nebula, the dark, well, dark nebula. There is also a star cluster here as this is a stellar nursery creating stars like the nearby Lagoon Nebula and winter’s Orion Nebula.

7/3/2021 Dark Nebulae

Saturday night at the River Ridge Observatory, while my DSLR was busy with Cygnus nebulae, my 11″ SCT was busy looking at dark nebulae. Here are some in the Small Sagittarius Star Cloud which is about 16,000 light years away. The star cloud itself is too large for this setup so we only see about half of it. This is a star cloud but you can see patches where there aren’t so many. Those areas have dark nebula that blocks the stars behind them. The one nearest the center is Barnard 92 (B92) and the one to the right of it is Barnard 93. Using my imagination, B92 looks like a man with long skinny legs facing mostly away from us while B93 looks like a turtle standing on his back legs maybe holding something in his front legs.

7/3/2021 Wide field full spectrum astrophotography

Here is something I worked on Saturday night at the River Ridge Observatory. It is the first light image of my full spectrum modified Canon T5i DSLR. The camera can now detect infrared and ultraviolet in addition to visible light. I will use it primarily for astrophotography but have always wanted to try the other two out. Because it is full spectrum, I will always have to use one filter or another or else it would be overwhelmed. Last night I used the same Optolong L’eNhance dual narrowband that I use for a lot of images. 90 two minute images went into this. I ran it until the battery ran out. I used my kit 70-300mm zoom lens at 70mm and f/4.So what we have here is part of Cygnus the Swan. in the lower left are the North America and Pelican Nebulae. Above them, the bright star is Deneb (tail of the swan). Over to the right and a little lower, is the star Sadr, which is the “intersection” of the swan with wings on either side, tail behind (no pun intended) and head the other way. Sadr has it’s own molecular cloud complex. All the red is ionized hydrogen glowing from the heat of nearby stars.A lot of room for improvement, for example I should have shot at f/5.6 to reduce coma and ISO 800 instead of 1600. Supposedly this camera is best for astrophotography at 800 rather than some lower ISO.