Jump to content


SGL 2021 Challenge 9 - Comets


Recommended Posts

The theme for challenge 9 is Comets.

Start Date: 1st December 2021
End Date: 28th February 2022

There is plenty going on for cometary imagers and sketchers in December and who knows what January and February will bring.  So let's see your best efforts and don't forget, sketches are very welcome

Prize: A personalised mug for 1st, 2nd and 3rd places featuring your image kindly provided by our sponsors FLO :) and a virtual trophy for your signature.

Please post your entries in this thread.  Please include details of your capture since this can be helpful to other members. Emojies are welcome but please don't comment on posted images.

Please do not post responses to individual entries since this clutters the thread, emojies are welcome of course.



All data must be captured and processed by you (no collaborative entries). 
Data must be captured during the challenge start & end dates. 
Multiple entries are allowed.
Multiple submissions of the same image, processed differently, will not be accepted.

  • Like 2
Link to comment
Share on other sites

  • MartinB changed the title to SGL 2021 Challenge 9 - Comets
  • MartinB pinned this topic
  • 2 weeks later...

(Also posted in Widefield, Special Events and Comets)  Having stayed up till 3:30 last Thursday night only for it to cloud over just as Comet Leonard cleared the rooftops I fortuitously woke a bit early this morning to find it clear,  so popped out with the binos and spotted it over the roof tops,  quickly opened the observatory and captured 36 mins or so of 30 second R, G and B subs on the Esprit100/ASI1600 and 1 min Lum on the Esprit150/SX46.   Data processed in Pixinsight using Comet alignment process to generate an aligned image of the comet, Starnet to extract the stars from the Star aligned image, Photoshop to remove the cometary blur from the starless star aligned image Pi to put the stars back, then Photoshop to combine the starry background with the comet .  I used the RGB to produce a colour image and the Lum to produce a short animation.  The red star top of frame is Tau01 Serpentis.

Thanks for looking





  • Like 22
Link to comment
Share on other sites

I Posted this in the comets forum before  I saw this competition. But here goes:  594570635_CometLeonardC2021-1.thumb.jpg.6b20143f0e6341ea8a5734a0450651e8.jpgDecember 5th, 2021, Valencia, Spain.  95 x 4 second livestack in Sharpcap using a 14¨ Dobson. This was a session of mixed emotions. From despondent to elated. After battling clouds high winds and bad flats,  I finally managed to get this 6 minute stack at 6.55 am while the comet was at about 48 degrees Alt. This was shortly before sunrise as the comet rose into a clear area of the sky.  It was much brighter than I expected. I could even see the head of the comet, with the scope,  when it was visibly light outside at 7.16 am. Expecting this comet to brighten several fold in the next week or so. In this image you an clearly see the reddish dust trail and the bluish ion tail/cloud. There is also  some good  detail towards the head
This image is a slightly cropped  direct output of a livestack using Sharpcap. No other postprocessing or enhancement   This was the best of multiple 5-10 minute stacks I made between 6 and 7 am.  The detail in the head always showed up within the first couple of minutes of stacking.

More details at Comet Leonard C/2021 A1 AT 6.50 AM December 5th (EAA) ( Mike Dobres ) - AstroBin

Edited by Mikeshuerto
  • Like 4
Link to comment
Share on other sites

December 9th, 2021, Valencia, Spain. 67P-Churyumnov-Gerasimenko zipping across the sky.  I was all set up to capture Comet Leonard again, and realized that this lump of rock was in the vicinity. This is a 152 x 4 seconds (10 minutes) Live Stack in Sharpcap.  The stack was then processed in Startools to produce the attached. Not quite as much detail as I captured with Leonard, but you still see a focus of heat/light in the coma. (Captured with my 14¨Dobson plus ZWOASI 294 MC pro). More details at https://astrob.in/bbpmyq/0/

There´s an interesting story behind this one. It was the  first comet to be orbited and landed upon by robots from Earth. The Rosettaspacecraft, carrying the Philae lander, rendezvoused with this comet in August 2014 and to escorted it on its journey to the inner solar system and back out again.  More here: 

In Depth | 67P/ Churyumov-Gerasimenko – NASA Solar System Exploration


Edited by Mikeshuerto
additional link
  • Like 3
Link to comment
Share on other sites

  • 2 weeks later...
  • 2 weeks later...

I was lucky enough to be in a dark sky area of Portugal on morning of 3rd December 2021. Crawled out go my camper van at 2:00am and set up my APM 152/1200 F7.9 telescope with a colour camera. Got these pictures around 3:00am

Here is the result: The comet passing M3 globular cluster. I feel very luck and privileged to have captured this picture. I have tried for hours to separately integrate the comet and stars in Pixinsight without success. The comet is too close to the cluster for any separation for rejection to happen. Happy to share the subs if anybody is feeling brave!


  • Like 14
  • Thanks 1
Link to comment
Share on other sites

I've never tried imaging a comet before but I was inspired to give it a go by some of the Leonard pictures out there. I don't regret it and I'm looking forward to doing it again with future comets 😄 These are my first attempts captured on new years eve and new years day using the setup from my signature. 20x45s and 40x20s.

C2021 A1 Leonard 45s Star stack-DeNAI-clear.jpg

C2021 A1 Leonard Comet stack 2-DeNAI-clear.jpg

  • Like 9
  • Thanks 2
Link to comment
Share on other sites

Comet C/2021 A1 (Leonard) 27/12/2021
Mount: Skywatcher EQ6-R Pro
Telescope: Orion 10" f/3.9 Newtonian Astrograph
Camera: Nikon D600 (stock)
Total exposure: 20 minutes
Subs : 15sec x 80
ISO: 400
Filter: Optolong UV/IR cut
Corrector: Baader MPCC Mark III Coma Corrector
Stacking: Deep Sky Stacker (Comet stacking mode)
Processing: Pixinsight
Location: Kaburugamuwa, Sri Lanka
Thank you.


  • Like 6
  • Thanks 1
Link to comment
Share on other sites

Time sequence of Comet Leonard passing through the stars in the morning of December 13, 2021. Each frame a Livestack in Sharp Cap. Imaged with a 14" Dobson and ZWO-ASI 294 MC PRO. I tried to align the images so the stars are aligned in each frame.






  • Like 2
Link to comment
Share on other sites

  • 3 weeks later...
  • 2 weeks later...
  • 2 weeks later...
  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.