Monday, March 10, 2008

Another (minor) outburst of comet Holmes - in progress right now?

This blog reported in depth about a possible weak 2nd outburst of comet Holmes in late January - and now THE ASTRONOMER Electronic Circular No 2430 has news about a third outburst in progress! "Images and photometry by several observers [...] suggest that comet 17P/Holmes has shown a further mini-outburst, which appears to have initiated on 2008 March 7," we learn: The R-magnitude of a 10 arcsec square aperture, equivalent to a physical aperture of 22000 km at the comet, went up from 16.1 to 15.7. Which for Mark Kidger and Richard Miles means a lot: "The three events detected so far have taken place at 44.6±0.6, 89.5±0.6 and 135.1±0.8 days after the initial outburst on 2007 October 23.7, giving a mean interval of 45.0±0.5 days determined from a least squares fit. The correlation coefficient of the fit is r2=0.99997. It is likely that this periodicity corresponds to the rotation period of the nucleus whereby the same area is activated when receiving insolation and thus it is concluded that 17P/Holmes is a very slow rotator, comparable to 29P/Schwassmann-Wachmann 1, which from Spitzer observations of its jets [...] appears to rotate with a period of 60 days or more."

In other news the 2008 ED8 vs. EZ7 mystery remains unsolved, but the 2nd NEA is now close. • The first ATV has been seen at +0.5 mag one day after its Kourou launch. • And claims about connections between galactic cosmic rays and Earth's climate take another hit - from astrophysics itself.


jm.tengco said...

i saw something like a comet (and alerted my friends via SMS, who in turn alerted their friends, one even told her students to view it in the middle of the exam she was giving them...) around 1930H GMT+8 (los baƱos, laguna, philippines) located somewhere in Perseus but nearer to Aries... but it faded in about 30-40 minutes....

i'm not sure if its really comet 17p Holmes on its supposedly 3rd minor outburst... (

but it could not be that Atlas V rocket from the satellite launch in California (0300H PDT, GMT-8) or could it be? the "comet" appeared on the west sky... just about the size of my thumb, arms length away.... while California is was east of the Philippines... hmmm...

but it really looked like a comet... it was stationary, and had a head and tail... looked more like an angel (pardon me for my description, hehe) with its 2 wings spread up high, the comet nucleus would be on the feet of the "angel" figure.... it was quote hazy (it was somewhere in the direction of manila... pollution made it look hazy...)

anyway, i would like to know/confirm if it really was a comet... and if it was/or wasn't, any other information regarding the sighting.... (like comet name, or what object?)

sincerely yours... :)

jm.tengco said...

oops... a mistype...

"quote" should be quite

anyway, thanks... really wanted to know about this since a few students also noticed that it faded too quickly... so some students might think we were a bit too excited... hehe

jm.tengco said...

whoops... found another mistype....
"while California is was east of the Philippines..."

just "while California is east of the Philippines..."

Theresa said...

Thank you for your precious information.

I am very interested in the further developing, further outbursts etc. of my "Friend", "Angel Holmes", and should be very pleased if you would keep me informed.

Thanks a lot

Chris Philipp

mails to

THANKS A LOT and many greetings from

Chris Philipp.