When comet C/2010 X1, detected by Russian amateur astronomer Leonid Elenin in images remotely taken from the International Scientific Optical Network’s robotic observatory near Mayhill, New Mexico, was announced, it has immediately stirred up excitement and enthusiasm in the community that the comet was predicted to become a fabulously bright comet as it comes near to its perihelion in late September and October. Consider the enhancement of foward-scattering in brightness and the light curve prediction based upon CCD measurement, it could have been even brighter to naked eye observers than does the prediction in MPEC at that time.
Inevitably, wicked doomsayers have been seeking for every chance to propogandize the doomsday in 2012, and the comet unfortunately has become their tool. But now, all is to be over — as if the comet were understanding that its pure reputation had been stained by those doomsayers, it was determined to yield to the power of the Sun and thus disintegrated.
The comet has been observed by several visual comet hunters since Apr 05 2011, when it was of around mag. 15. The comet kept brightening since Jun, and by mid Aug, its brightness climbed up to mag. 8. I also attempted to observe the comet in early evening on Aug 20, however, as the light pollution in the west from downtown was pretty severe, I failed to discern stars faint to mag.7 around and sure enough failed to catch sight of the comet. As the comet is heading towards the Sun and the conditions become more and more unfavorable, I thought I could only observe the comet when it emerges in the predawn sky after perihelion.
However, it was Aug 22 that Michael Mattiazzo first published in the comets-ml Group about an evident decline in brightness of the comet. Below are his images (with his kind permission):
Clearly judging from the images, it can be learned that the pseudonucleus is becoming fainter and fainter and more and more diffuse, indicating disintegration of the nucleus according to my experience and knowledge.
There are also data reflecting the process (excerpted from http://webs.ono.com/jpab/):
2011 Aug. 23.39 UT: m1=8.9, Dia.=3′, DC=3…25x100mm B…Michael Mattiazzo(Castlemaine, Victoria)
2011 Aug. 22.37 UT: m1=9.0, DC=2 , Dia=3.5’….30cm Dobson….Con Stoitsis ( Australia )
2011 Aug. 21.31,UT: m1=8.6, Dia=4′ (S.T. Rae, Hamilton, New Zealand, 9×63 binoculars);
2011 Aug. 20.31,UT: m1=8.3, Dia=5′ (S.T. Rae, Hamilton, New Zealand, 9×63 binoculars);
2011 Aug. 19.39 UT: m1=8.1, Dia.=4′, DC=4…25x100mm B…Michael Mattiazzo (Castlemaine, Victoria)
2011 Aug. 17.39 UT: m1=8.2, Dia.=4′, DC=4…25x100mm B…Michael Mattiazzo (Castlemaine, Victoria)
2011 Aug. 16.91 UT: m1=8.3, Dia=3´,DC=4…20x80B Willian Souza (Sao Paulo, Brazil)
2011 Aug. 16.91 UT: m1= 8.3, Dia=4′, DC=3…18cmL (57x)…Alexandre Amorim(Florianopolis,Brazil)
I reminisce about comet C/1999 S4, which also experienced a similar process in 2000. Now it would have been a great chance of studying the dynamical process and composition of the nucleus of C/2010 X1 were the elongation better and more favorable.
Anyway it’ll be expecting to see whether some of the swarms of the debris can survive their perihelia. If there’s any of them detectable, nothing could have been better since we may be capable of obtaining some poor-known parameters of long periodic comets by calculations!
Btw, due to my hectic lifestyle, I haven’t been able to get some time to check the HI1B images in fts format myself. But I think it won’t be difficult to measure its brightness with which I can combine other parameters provided by some planetarium software, some knowledge of what comprises this comet would be able to be achieved and smattered hopefully.