σ Ori and friends 9.13.2023

[pakarinen]

Woke up about 0400 and was finally feeling better after my COVID rebound, so I took out my ST102 to try to get back into my pre-dawn observing routine.

Pooted around Orion a bit before slewing over to σ Ori. Sigma Ori along with multiple star Struve 761 and HD37525 make up a nice Sagitta-like asterism, close to the Horsehead. 37525 is a double, but it’s a bit too tight for the scopes I’ve used on it. I was able to clearly separate E and D from σ AB, but I wasn’t able to pick out C. Some people have commented that C can be difficult due to its low brightness (mag = +8.8) and close proximity to AB.

I was also able to resolve Struve 761 A and split BC pretty easily at 50X. Increasing the magnification to 85X smeared BC out – they were easier at 50X. Interestingly, my 10mm SLV EP seems to be the sweet spot for all my scopes.

Here’s a nice chart with rollover names:
https://www.skyledge.net/SigmaOrionis.htm

Twilight was coming on, so I took a quick look at the Trapezium – yup, it’s still there – and then a quick look at open cluster M35 before going in and getting ready for work. If the weather cooperates and I wake up early enough tomorrow, I’m going to take another look at σ with my AT72EDII, just to compare. And maybe I’ll remember to put a dew band on the scope finally.

[Bigzmey]

Nice double session Olen. Glad that you are feeling better.

Interestingly, my 10mm SLV EP seems to be the sweet spot for all my scopes.

That's not a coincidence. Your 80m, 100mm and 120mm are all F5 scopes. 10mm EP produces 2mm exit pupil in all three. In turn, 2mm exit pupil provides best combination of brightness and contrast for majority of DSOs and provides best color definition for stars.

[StarBru]

Loved your report, Olen! And thanks for the handy chart! Since I have been unable to observe lately between the weather, my work schedule, and my wife's busy social calendar and to do list for me on the weekends, I can live vicariously through reading reports like yours!

[helicon]

Nice double star report Olen and congratulations on winning the VROD for today! (9/14/2023)

[pakarinen]

Well the 72ED couldn't split Struve 761 BC this morning, but I was out closer to sunrise and I wasn't paying much attention to the seeing or transparency, aside from them not being horrible. Did split Castor nicely.

[Unitron48]

Nice session, great reporting! Congrats on your VROD recognition.

Dave

[John Baars]

Very nice report! Congratulations on the VROD!

[kt4hx]

Another nice double report Olen, and congrats on the VROD. The included chart for Sigma Ori is a great tool - thanks!