June 2025

Welcome to Hank’s June 2025 Astrophotography Blog. Star party season is upon us, and Black Hills Astronomical Society had about 75 show up at our Hidden Valley Observatory for an evening under the stars on the 20th. We had a variety of telescopes lined up, and after folks got their video introduction to the night sky and checked out our Observatory, they mingled around to each of the telescopes to see what was going on. I always love the kids that come by—they always have great questions, and the kids from Mission, SD were no exception. I had my Seestar S50 set up and after a glitch in setting up in the equatorial mode, I switched over to Alt/Az mode (Thanks to Jim for loaning me his 5mm hex wrench). Equatorial mode tilts the mount at the location’s latitude (about 44 degrees in Rapid City) and tracks the movement of the heavens along that arc. Alt/Az mode has the mount sitting up straight, and moves the telescope up/down and over to track. If you need to know more, check out:

https://telescopeguides.com/alt-azimuth-mount-vs-equatorial-mount-what-to-choose/

My Seestar S50 does “live stacking” so as it takes photos of a target, it stacks the images one on top of the last, bringing in more details on my iPad with each photo taken. Sometimes at star parties I like to just take one image, and over the course of the evening, a well defined image comes in. This time I thought I’d try to take shorter exposures and get more targets, to see how they’d turn out. In all I took photos of 6 targets, ranging from 6 to 40 minutes of exposure time. For the images shown here in the blog, I used the raw files that SeeStar saves and did my own post processing at home the next day, to get better defined images than the Seestar does on the fly during the capture. Here are 5 of them: 3 galaxies, a globular cluster and a Nebula.

Partway through the evening, Kent and Barb, two BHAS members, stopped by my telescope and Kent asked if I’d pull up an Open Star Cluster for him. I’ll be honest, I’ve taken a number of photos of Open Star Clusters, and they really don’t excite me much—not much for nebulosity, colors, or unusual features. They are usually just a few dozen stars that are visually close to each other and gravitationally tied together. But they do make good visual targets when looking though the eyepiece of a telescope, though. The one that Kent and Barb wanted me to zero in on was NGC 457, commonly called the ET Cluster, and named after the ET character in the movie. This is not one that I’d photographed before, plus it is a Caldwell Catalog target (C13) and I’m always looking for new Caldwell targets to photograph. Kent pointed out the outline of the ET asterism on my iPad, and I think I see it now. The two bright stars are ET’s eyes, then below the eyes are his long-outstretched arms, and then below the arms are ET’s squatty little legs. Can you spot ET, too? Now that I look at it, I can almost see the three stars in his chest that might be his heart!

I worked on imaging two nebulas this month, trying to gather enough hours of light to show more details than I’ve been able to tweak out in the past. For M27, I took 81 x 5-minute exposures (81×5=405 minutes; 405/60=6 hours and 45 minutes) and was able to bring out more of the nebulosity that surrounds the object so I was happy with that. For M16, I was able to take 118 x 5-minute exposures and captured almost 10 hours of light. It’s not like the famous Hubble or JST image of the Pillars of Creation, but I just don’t have the billions of dollars to invest in that kind of telescope. You can check out NASA’s photos here:

https://www.nasa.gov/universe/nasas-webb-takes-star-filled-portrait-of-pillars-of-creation/

To get 10 hours of light, I had to take the photos over 3 nights. In the winter I could almost get that much light in one night, under the right circumstances. But near the Summer Solstice, it is just not dark long enough to capture many hours of objects in the night sky. I usually only have about 4.5 hours of darkness available to me. Then I have to subtract the images where clouds got in the way, or when the object dipped behind the trees….it just takes time!

Until next month, Clear Skies!!! -Hank