Had one friend visiting overnight Friday night for a peek at the comet yesterday morning. After three days of cloud, I was looking forward to observing any changes.
Got my gear set up. I also set up a second iOptron iEQ45 mount for Denis' camera. By doing this, we then both loaded our SkyWatcher Star Adventurer's in my 4wd SUV ready for a run west if necessary. Cloud was predicted out to the east. I couldn't tell how much it would interfere with comet observations so we were ready to make a run to the west. I went to bed at 11pm and woke at 1:30am couldn't get back to sleep. 🥴 Greeaat!! 2.5 hrs sleep....Oh well, I can sleep when I'm dead. Got up just after 2am, checked the sky. T'was a lovely clear morning. A degree or two of thin cloud on the horizon. We decided to stay at the house and not travel. It was a 2:30am and the comet would not rise for another two hours. After checking that the telescope mounts were tracking and ready for action, there was nothing left to do but to switch on the Espresso machine and turn out two strong coffees, tailor made for a stupidly early start like this.
Comet C/2023 A3 rises at 0430am on 28th September, 2024 AEST. [20240927.77 UT]
Visual Observations
Using 15x70mm Celestron Skymaster Pro binoculars, I observed a tail filling 3/4 of the 4.4o field of the binoculars soon after rise while significant extinction was evident. Denis said he could not see past the inner tail.
After the comet attained 7o altitude:
Using 10x42 ED binoculars and using Nu Hydrae [Mv 3.08] and Mu Hydrae[Mv 3.81] I estimated the comet to be Mv 3.6 using IN-IN method.
Using averted vision, i could detect the nucleus with the very faintest hint of a tail.
In 42mm binoculars, the dust tail was quite obvious and in 70mm binoculars, the tail spanned the full 4.4 degree field of the binoculars. It is brightening each day now so get out any clear morning and have a look if visible from your location.
I captured two sequences of images one with 135mm f2 and the other an 8" f 6.4:
1. Pentax K5 (APSc) Rokinon 135mm ED f2 - single exposure ISO 800 30s f2
2. Pentax K5 (APSc) Rokinon 135mm ED f2 - 11 exposure stack ISO 800 30s f2
3. Pentax K1 (full frame) Vixen VC200L 8" ƒ6.4 1280mm focal length 11 exposure stack ISO 12,800 11 x 20s f 6.4
So much sleep sacrificed for a mere 20 - 25 minute frantic observing and photography.
Joe
