Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: MarkS on Dec 30, 2014, 23:26:14

Title: Lovejoy C/2014 Q2 meets M79
Post by: MarkS on Dec 30, 2014, 23:26:14
This is a reprocess of Sunday night's data.

Canon 350D on Tak Epsilon 180ED.  30 x 60sec exposures at ISO 800

It's my first attempt at composite processing of a comet image i.e. making both the comet and star background appear static.

(http://www.markshelley.co.uk/Astronomy/2014/lovejoy20141228v3.jpg)

Mark
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: Kenny on Dec 31, 2014, 03:49:16
Fantastic. I saw the comet this evening from Wimbledon Common and it looked nowhere near as good as that. :P
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: MarkS on Dec 31, 2014, 07:01:05
I may to revisit my composition process because I've noticed that the tail is more visible in one of the intermediate stages of processing than it is in the final result:

(http://www.markshelley.co.uk/Astronomy/2014/lovejoytail.jpg)

The huge problem is that with the comet being down in the murk, the image background gradients are changing from exposure to exposure.  The background gradients also add data noise.  I'm sure it's much easier to process when you are using data shot remotely from Siding Springs in Australia!
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: The Thing on Dec 31, 2014, 11:54:01
That should be in Astronomy Now, it's great. No other image I've seen so far shows the twisted tail like that.
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: MarkS on Dec 31, 2014, 16:09:18
Quote from: The Thing
That should be in Astronomy Now, it's great. No other image I've seen so far shows the twisted tail like that.

Today's APOD (http://apod.nasa.gov/apod/ap141231.html) also shows weird but different structure to the tail.  I reckon it was taken an hour or two before mine.  Interesting how much it changes.
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: Fay on Dec 31, 2014, 20:00:26
fantastic Mark!!!!!
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: MarkS on Jan 02, 2015, 16:44:19
Quote from: The Thing
That should be in Astronomy Now, it's great. No other image I've seen so far shows the twisted tail like that.

I've sent them the new improved bigger version:
http://www.markshelley.co.uk/Astronomy/2014/lovejoy20141228v4.jpg

I'm pretty happy with the result considering it was sitting in the murk 13 degrees above the horizon (the decision to have fold down flaps on the observatory has been vindicated).  I'm really looking forward to it higher in the sky in January.

Mark
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: Fay on Jan 02, 2015, 18:13:33
Great Mark, glad it is going to get higher
Title: Re: Lovejoy C/2014 Q2 meets M79
Post by: MarkS on Jan 02, 2015, 18:22:45
It will be nicely placed and nicely bright for the January DSC.