Re: [BAA Comets] 12P/Pons-Brooks in outburst!
Nick James 23 Jul 2023 06:42 UTC
Another image from the Alnitak CDK 17 here:
https://britastro.org/observations/observation.php?id=20230723_062749_9728e378f3730283
I get a coma expansion velocity of around 160 m/s by comparison of two
images taken 21 hours apart and the total magnitude is almost constant
implying a single impulsive release of material into the coma. The
teardrop shape is still prominent.
Nick.
On 22/07/2023 10:21, Nick James wrote:
> We are currently evaluating a remote observatory in Spain for use by BAA
> observers and I used this to get a high-resolution V-band image (0.26
> arcsec/pix) of the coma last night.
>
> This image was obtained using the 0.45-m f/6.6 CDK at the Alnitak
> Observatory in Spain. It shows a tear-drop coma with a dark lane around
> PA 10 deg. The total magnitude in an aperture of 26 arcsec was 11.6.
>
> https://britastro.org/observations/observation.php?id=20230722_091422_63610293e41f0496
>
>
> Nick.
>
>
> On 22/07/2023 00:25, Nick James wrote:
>> I've just (July 21, 23:20 UTC) managed to image it through hazy cloud
>> here at 970 and I get a total magnitude of 11.8 with a roughly
>> circular coma of diameter 26 arcsec. The image FWHM is 2.5 arcsec.
>>
>> The image is here:
>>
>> https://britastro.org/observations/observation.php?id=20230721_232012_f5b4a3cb5e9dfe31
>>
>>
>> Nick.
>>
>
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