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Leonard and galaxies


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Comet C/2021 A1 LEONARD brightened nicely towards the end of November 2021, and was due to pass near the interesting galaxies NGC 4631, the 'Whale' and NGC 4656, the 'Hockey Stick' on the night of 24th. Rising late and not at a decent height until after 2 am, but the forecast was for clear sky, so I set up my Canon 700D camera on my Meade 127 refractor with TS FLAT2 field flattener. The sky did clear beautifully, but unfortunately there was a bright 73% mag -11 waning gibbous Moon. Because of the bright moonlight (the Moon was a little over 50 degrees from the target) difficult to reduce noise. 9 x 5 minute ISO 1600 subs. Processed with Darks and Flats in Deep Sky Stacker, but using the clever system to align on both the comet and stars. It doesn't always work, but this time was successful. Finished off in Photoshop.

Cheers,

Peter

Leonard.jpg

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Thanks guys,

Worth noting that in the early hours of 3rd December the comet passes very close to the globular cluster M3.  According to Skymap Pro the closest approach will be around 3.25 am when it is just 6 arc-minutes from the centre of the cluster at 26 deg altitude.  So a late nighter - pity it's a Friday morning for those who have to go to work 😴  Of course Sod's Law means it will be cloudy, but if not I'm going to try for a long sequence of images from around 2.00.  Very low in the East at first (only 15 deg altitude), but rising to 47 deg by the start of twilight.  Fingers crossed! I haven't yet decided which optics to use.  At 2 metres the tail will initially stretch out of the field of view.  But that will give a good view of M3 particularly later on when the tail should lie right across M3.  On the other hand at 950 mm the movement of the comet (which is quite fast moving) will not be so obvious in each frame. 

Editing.  Just checked a few forecasts for next Thursday night.  Nearly all forecast rain.  Which means it's probably going to be clear 😉  And of course those altitudes and times are for Northumberland UK - will be different for other locations.

Cheers,

Peter

Edited by petevasey
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Excellent image ,

I tried to capture this scene with a Pentax k70 and 55-300 Pentax zoom on a static tripod. I had 9 minutes of data, but DSS ended up stacking just over 5mins. 

I'm a beginner and only used DSS once before. Hope you don't mind me asking a couple of questions 🤓.  

Did you move the comet away from nearby stars before stacking using the comet settings? 

Any tips on getting the really black background, I tried this before with 46P Wirtanen, I think I stretched the stacked subs in DSS. I understand It's best not to do the stretching in DSS ? 

I don't have photoshop but I use rawtherepee. 

After stacking did you move the RGB histograms to align over each other in DSS.? 

Thanks 

Edited by scotty1
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7 hours ago, scotty1 said:

Excellent image ,  Thank You!

I tried to capture this scene with a Pentax k70 and 55-300 Pentax zoom on a static tripod. I had 9 minutes of data, but DSS ended up stacking just over 5mins. 

I'm a beginner and only used DSS once before. Hope you don't mind me asking a couple of questions 🤓.  

Did you move the comet away from nearby stars before stacking using the comet settings?  No, although I don't understand what you mean by 'move' the comet.  I just click on the comet head using the enlargement to get as close as possible.  Hold 'Shift' key down for fine positioning of the cursor.

Any tips on getting the really black background, I tried this before with 46P Wirtanen, I think I stretched the stacked subs in DSS. I understand It's best not to do the stretching in DSS ?   I use Photoshop, and just play with the 'Levels' setting, usually several iterations..

I don't have photoshop but I use rawtherepee.  Can't help there I'm afraid.

After stacking did you move the RGB histograms to align over each other in DSS.?  Yes, but still usually have to adjust the colours later, partly because my Canon 700D camera is modified for astro use, so has a reddish tint.

Thanks 

Cheers,

Peter

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7 hours ago, Mark at Beaufort said:

Peter I was really hoping that someone would produce an image of this event. The Whale and Hockey Stick are one of my favourite DSOs and you have done an excellent job.

Thank you, Mark.  I have a close up image of the galaxies taken in 2009.  On my web site here.

Cheers,

Peter

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