[BAA Comets] Comet 17P/Holmes: A marked outburst on January 26

[Richard Miles]

Brilliant Nick - I am amazed!

Try measuring also with Astrometrica using 'Background from Aperture' option 
and choosing a measuring aperture size that encompasses all of the coma. 
That should confirm also.

If the expanding coma is now up to 30 arcsec across then the outburst would 
have happened on 2015 January 27.

I need to put a request in for some more 2.0-m imaging however there is no 
guarantee I can get them (next scheduled observation is on Jan 30). So it 
would be good if observers can follow the development of the coma tonight.

Richard


----- Original Message ----- 
From: "Nick James" <ndj at nickdjames.com>
To: "BAA Comets discussion list" <comets-disc at britastro.org>; "Richard 
Miles" <rmiles.btee at btinternet.com>
Sent: Wednesday, January 28, 2015 7:25 PM
Subject: Re: [BAA Comets] Comet 17P/Holmes: A marked outburst on January 26


> Richard,
>
> Using non-offset stacks in Astrometrica to get the ZP and aperture 
> photometry in IRIS using a 30 arcsec aperture I get 14.5 using an 
> unfiltered ST9. The detected coma diameter is 30 arcsec.
>
> Nick.
>
>
>
> _______________________________________________
> Comets-disc mailing list
> Comets-disc at britastro.org
> http://lists.britastro.org/mailman/listinfo/comets-disc
>