August 19, STEREO-B spacecraft has catched a very interesting event – the interaction of the gas coma of comet Elenin and coronal mass ejections from the Sun. On the video we can clearly see dynamics of the cometary tail, which squirming under the influence of powerful pressure of solar wind. After a brief increase, the brightness of the comet began to decreasing within a few days and reached a level of brightness that the comet was in early August.
On the picture taken by the well-known Australian astronomy amateur, Terry Lovejoy, which discovered his comet in 2007, is clearly visible long and thin ion tail stretching almost one degree! Which corresponds to the length of the tail is more than 3,000,000 km! Although this is not a record, the sodium tail of comet Hale-Bopp had a length of nearly 50 million kilometers! Comet Elenin will pass closest to the Earth on October 16 at distance about 35 million kilometers from our planet.
My estimate the size of the comet Elenin coma was confirmed by visual observations of an experienced Australian amateur astronomer Michael Mattiazzo. August 19, he estimated the angular size of the coma as 4 arc minutes, which equal to 213,500 km in the linear size. The image of the comet, taken by Michael, on August 19 as you can see on the left and on own author’s site.
I remind, that in the next few days, we have chances to see the comet C/2010 X1 (Elenin) in the coronagraph COR2 field of view, which mounted on the STEREO spacecrafts.
The new monthly MPC circular released – MPC 75551- 75798.
ISON-NM statistic for the previous month (July 8 – August 8):
Number of measurements: 5378
Measured objects: 1290
Discovered objects: 3
Sky coverage: 205 sq. degrees
Observing nights*: 21
* – include partial nights