Friday, April 10, 2015

New Comet: C/2015 G2 (MASTER)

CBET nr. 4092, issued on 2015, April 10, announces the discovery of a comet (magnitude ~11) on R-band images taken by P. Balanutsa et al. with the MASTER (Mobile Astronomical System of the Telescope-Robots) 0.4-m f/2.5 reflector at the South African Astronomical Observatory.  The new comet has been designated C/2015 G2 (MASTER).

We performed follow-up measurements of this object, while it was still on the neocp. Stacking of 10 unfiltered exposures, 30-sec each, obtained remotely on 2015, April 08.8 from Q62 (iTelescope network - Siding Spring) through a 0.50-m f/6.8 astrograph + CCD + focal reducer, shows that this object is a comet with a very bright coma nearly 3 arcmin in diameter and a tail about 15 arcminutes long in PA 253.

Our confirmation image (click on it for a bigger version)

M.P.E.C. 2015-G28 (including pre-discovery MASTER observations from Mar. 30.1 UT, showing the comet at mag 11.5-11.6) assigns the following preliminary parabolic orbital elements to comet C/2015 G2: T 2015 May 23.80; e= 1.0; Peri. = 257.48; q = 0.78;  Incl.= 147.56

Below you can see a graph generated using the software Orbitas and showing the C/2015 G2 predicted magnitude (in red) versus its elongation from the Sun. Click on the image for a bigger version.

by Ernesto Guido & Nick Howes