Re: [BAA Comets] Comet 17P/Holmes has gone into outburst !!
Nick James
(09 Aug 2021 21:43 UTC)
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Re: [BAA Comets] Comet 17P/Holmes has gone into outburst !! Richard Miles (09 Aug 2021 21:50 UTC)
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Re: [BAA Comets] Comet 17P/Holmes has gone into outburst !!
Nick James
(10 Aug 2021 02:17 UTC)
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Re: [BAA Comets] Comet 17P/Holmes has gone into outburst !! Richard Miles 09 Aug 2021 21:50 UTC
All part of the service, Nick. That's great news that you imaged it on July 29 - that's perfect and fits with my estimate of the timing. I didn't expect anyone to be following 17P given that it's at about 60 degrees solar elongation in the morning sky! I used the images of its 2015 January strong outburst to estimate the number of days the outburst coma has been expanding - that earlier event is well documented on the BAA website at: https://britastro.org/node/6226 Cheers, Richard ----- Original Message ----- From: "Nick James" <ndj@nickdjames.com> To: <baa-comet@simplelists.com> Sent: Monday, August 09, 2021 9:43 PM Subject: Re: [BAA Comets] Comet 17P/Holmes has gone into outburst !! > Richard, > > Thanks for the alert. > > The formatting seems to be messed up on your comets-ml message but I think > it says that the comet was 17.30 on July 20 and 16.02 on August 8. How did > you determine the time of the outburst as Aug 3? > > My last image of it was on July 29 when it was around mag 17.0 (unfiltered > vs Gaia DR2 G) in a 9 arcsec radius aperture: > > https://britastro.org/cometobs/17p/17p_20210729_020259_ndj.html > > Morning objects are not good for me on weekdays but I'll have a go at it > next time I get a chance. > > Nick. > > > On 09/08/2021 22:05, Richard Miles - rmiles.btee at btinternet.com (via > baa-comet list) wrote: >> 17P/Holmes is well known for its unique 13-14 magnitude mega-outburst of >> 2007 October 24. >> This enormous outburst did not disrupt its nucleus, which appears to be >> still intact. >> >> On or about 2021 August 03, the comet was just 3 degrees away from >> reaching the same position in its orbit when it underwent its dramatic >> mega-outburst of 2007. During the intervening years, it has made not >> quite two orbits of the Sun. >> >> The current outburst looks to be 1.4 magnitudes amplitude, meaning that >> it has brightened by almost a factor of 4, i.e. a very significant event >> indeed. >> >> We might expect some repeat small outbursts every 36-44 days. >> >> More details have been posted on the 'comets-ml' mailing list at: >> >> https://groups.io/g/comets-ml/message/29901 >> >> Richard Miles >> >> To unsubscribe from this list please go to >> http://archives.simplelists.com > > To unsubscribe from this list please go to > http://www.simplelists.com/confirm.php?u=aR5jVcAm0PpxqWzIIDZTQWdURWgNdCOC