141P/Machholz 2 = 1994 P1

 

Discovered as a magnitude 10 object by Don Machholz on August 13^th 1994 this is an interesting and curious short-period object, with a period of just 5.23 years and perihelion just a fraction outside the orbit of Venus. Two weeks after discovery a second, co-orbital component was found more than three quarters of a degree behind the main comet and, in the first week of September, three more faint components were found. From west to east these fragments were designated A through to E. It was evident that the comet had suffered a major fragmentation event at a previous return from perihelion and there was even a suggestion that the fragmentation was ongoing as a double nucleus of “D” was reported in October. The large size of the non-gravitational component of motion suggests that unusual activity is still present.

 

Fragment “A” was recovered on August 3^rd 1999 and, later, “D” on October 17^th. Both brighten very rapidly as perihelion is approached with fragment “A” passing from being between magnitude 20 and 21 at recovery, to magnitude 11 in just 3 months.

 

Component “D” faded out during December 1999 and just two observations were reported after perihelion, both at the end of December. Although component “A” reached magnitude 11.5 in 2005, “D” was not recovered and is presumed to have disappeared.

 

 

This comet is relatively challenging for CCD observers as it is only bright when at rather small elongation. During the 2005 apparition we have just a single total visual magnitude estimate by J.J. Gonzalez at m₁=11.7 on March 11^th (T+12 days).

 

A 71 minute integration on the comet (left) by Ramon Naves at MontCabrer (MPC 213) on April 13^th failed to detect the comet.

 

Other attempts to detect the comet by CCD observers in late April and early May 2005 failed to locate it to magnitude 18 (more than 3 magnitudes fainter than the expected magnitude) so there is a possibility that the comet has faded out and will not be recovered at its next return in 2010 when it is expected to reach magnitude 12 in mid-June.

 

Detailed information on the observational history of 141P/Machholz 2 can be found at Gary Kronk’s wonderful site, here.

 

Seichii Yoshida gives light curves for the 1999, 2005 and 2010 returns on his site, here.