Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Rick on Nov 02, 2007, 12:02:17

Title: Comet Holmes changes
Post by: Rick on Nov 02, 2007, 12:02:17
It's been interesting to see how the comet's changing from day to day. Has anyone yet collected enough images over time to make a sequence showing the changes? There was one a few days back on APOD which only covered a few days...
Title: Re: Comet Holmes changes
Post by: MarkS on Nov 02, 2007, 17:56:34

Enough images to make a sequence?  What, from cloudy Kent?  :(
Title: Re: Comet Holmes changes
Post by: MarkS on Nov 03, 2007, 07:36:32
The best I can put together is a sequence of 3 (28,29,31 October):
http://homepage.ntlworld.com/the_shelleys/photos/holmes_animation.gif (http://homepage.ntlworld.com/the_shelleys/photos/holmes_animation.gif)
Title: Re: Comet Holmes changes
Post by: Jim on Nov 03, 2007, 09:14:12
Mark

Brilliant, that's really an interesting sequence.  Fascinating to see how it changes.  There's a pic on the SPA site that shows a distinct tail
(http://www.popastro.com/img/obspot/obspot038.jpg)
Title: Re: Comet Holmes changes
Post by: JohnP on Nov 04, 2007, 14:38:00
Really excellent Mark - great work... John
Title: Re: Comet Holmes changes
Post by: MarkS on Nov 05, 2007, 06:09:35
I've now added a 4th image so it covers the evenings of:
28 Oct, 29 Oct, 31 Oct, 4 Nov

The 3rd and 4th images in the sequence have been brightened by factors of 1.5 and 3 respectively in order to show detail because the comas are now getting much larger but much fainter.  The 4 exposures are each 2min (4 x 30sec at ISO 400) using a Canon EOS 300D SLR on a Celestron C11 with F6.3 focal reducer and then 2x2 binned before taking a 512x512 crop.

http://homepage.ntlworld.com/the_shelleys/photos/holmes_animation4.gif (http://homepage.ntlworld.com/the_shelleys/photos/holmes_animation4.gif)
Title: Re: Comet Holmes changes
Post by: Rick on Nov 05, 2007, 08:32:48
It's interesting to see how the shell of material that was shed now seems to be being left behind (or blown ahead by the Solar Wind?) while the comet goes its own way.
Title: Re: Comet Holmes changes
Post by: MarkS on Nov 15, 2007, 23:03:26
I've now added images 5 & 6 to the animation so it covers the evenings of:
28 Oct, 29 Oct, 31 Oct, 4 Nov, 8 Nov, 14 Nov

I've had to compensate for the continuing reduction in brightness.  It now more or less fills the field of view of my Celestron C11, so I'll pass the baton to you widefield guys now ...

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/MDS_holmes17p_anim6.gif)
Title: Re: Comet Holmes changes
Post by: Mike on Nov 16, 2007, 08:18:39
Weather permitting i'm hoping to get out this weekend and take some shots with my D70 either with its own lens or on my ZS66. Nice sequence Mark.