Comet Garradd - 26/03/2012

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Christian Buil
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Comet Garradd - 26/03/2012

Post by Christian Buil »

A C11 + LISA observation of comet Garradd C/2009 P1 (coma region) - March 26.8 2012:

Image

The comet is well positionned and bright but not a so easy object for me because
sky pollution...

The 2D image of comet + sky (6 x 300 s):

Image

The comet is faintly visible relative to sky intensity. The pollution intensity is
dramatic. Now a 6x 300 s exposure of a sky field (no comet):

Image

The substraction of the two images reveal the comet:

Image

ISIS processing. Details here:

http://www.astrosurf.com/buil/garradd/obs.htm

Christian B
Olivier Thizy
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Joined: Sat Sep 24, 2011 10:52 am
Location: in the french Alps...
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Re: Comet Garradd - 26/03/2012

Post by Olivier Thizy »

OK - here is my spectrum of C/2009 P1 Garradd in 1h exposure with LISA + Televue 85. Not as good but features well visible...

To process it, I created a dummy dark & offset frame (note: I had to do it in AudeLA and not ISIS as I had to set the exposure time for the dark). I then substracted the comet 2D images with the sky background images and added them together into a single 2D image to process.
This worked but I still have strong emission lines visible in my image - some pollution I couldn't remove.

Anyway, here is the spectrum profile:
Spectre de la comète C/2009 P1 Garradd.
Spectre de la comète C/2009 P1 Garradd.
20120331 C2009 P1 Garradd.png (5.6 KiB) Viewed 3977 times

Cordialement,
Olivier Thizy
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