Comet C/2018 Y1 Iwamoto with NGC 2903 Galaxy from the city

It is always frustrating to see good weather pass without the opportunity to do some photography – especially astro-photography. So even if time does not permit a trip to the darker spots in reasonable distance from my home, it is worth a try to setup the telescope on the balcony.

This time, clouds cleared throughout the day (and happend to reappear before midnight). So I had to take the chance to spot Comet C/2018 Y1 Iwamoto. Unfortunately, I was unable to spot the comet through the eyepiece. The sky was far too bright (approximately 18mpss) watching straight over the citys light dome and having a 60% illuminated moon shining bright. Fortunately, through the camera I could make out a smudge, being brighter than the sky.

Processing the 180s subs with 1 hour total exposure time, I could achieve this result (compare to the unprocessed image!):

Image is a composite of 2 stacks (one aligned on stars, second aligned on comet). The comet moved more than 1.5 degrees during the 1 hour capturing time!
Above the comet: NGC 2903 (mag 9 galaxy)
At left: NGC 2916 (mag 12.1 galaxy)

Imaging setup: 800mm f/4.0 Newton, Sony A6000 full spectrum modified, UV/IR block filter, UHC filter, coma corrector (at wrong distance).
20x 180s @ ISO800, darks and flats
Conditions: +2°C, 60% moon, 18-18.5mpss sky in suburban location (with ample street light)

Comets during full moon

After 2 weeks of thick cloud coverage, I had the chance to spend the evening at the observatory. Actually I jumped in to hold the guided tour this evening…
As there was almost full moon and some cloud coverage (which got steadily thinner) I played a bit around with the setup. I thought – deep sky at full moon is a waste of time. But how about the comets 46/P Wirtanen and 38/P Stephan-Oterma? How brigth are the comets still? Would they shine through the moon lit sky?
Well… I could not make out Stephen-Oterma. But Wirtanen was barely (in)visible. I had some other tasks to do, so I attached the camera to the scope and let it run to see, what may be gathered under these conditions.
Despite of the Moon and the corona of Moon, a little bit of the comets was still possible to process from 90 minutes of total exposure time each:

Comet 46/P Wirtanen travelling through space

The following timelapses show, how much angular distance the comet 46/P Wirtanen makes, when closest to earth. From my data I see approximately a stunning 1° during 4 hours!

Timelapse 1:
85mm photo lens with 1.5x crop sensor
93 exposures, each 60 seconds long (93 min total)

Timelapse 2:
200mm photo lens with full frame sensor
160 exposures, each 90 seconds long (240 min total)

Timelapse 3:
715mm/f7 APO with 1.5x crop sensor
71 exposures, 30 and 60 seconds over 80 min

2018-12-08 Comet 46/P Wirtanen comes closer

After several days with clouds, there has finally been a window of a few hours with stars visible. Unfortunately I had no chance to reach acceptable dark skies. So I had to deal with a more or less 5.5mag sky and some clouds passing by in eastern Austria. This image shows a bit more detail of Comet 46/P Wirtanen, as I used a 200mm telephoto lens. The result is not yet the image I am looking for. So I hope that clouds will clear up the next days for a better and longer imaging session…

2018-11-28 Comet 46/P Wirtanen

Finally the full moon is over. The first chance to properly see some fainter objects like the comet 46/P Wirtanen. Comet 46/P Wirtanen started to rise more and more from the horizon. At November 10 the comet reached only 10° above the horizon. Now it is at approximately 20°. As for one day on November 28 the sticky clouds opened up above Austria. So I packed my gear and headed to the mountains. I ended up at a snow covered mountain top near Lachtal at 1857m a.s.l. At -8°C seeing, transparency and sky darknes were exceptionally! A really treat to observe 🙂
I set up my camera with a 85mm lens and captured 90 minutes of data until the moon rose. I chose the 85mm as I expected to see a tail extending from the comet. But as it seems, the tail is not extening sideways (seen from Earth) at the moment.
I am really pleased with the results and hope for another chance of good weather within the next few days…