Friday, 27 February 2015

OT: another update on NEA 2015 CA40

Our Near Earth Asteroid discovery (see earlier post) 2015 CA40 is now past it's point of closest approach. It reached that point, at 6.3 lunar distances, on Feb 23 near 21:49 UT.

The animated GIF above shows the asteroid early on Feb 24, about 12 hours after closest approach, imaged with the 0.61-m F/10 Cassegrain of MPC G68 Sierra Stars Observatory in California, USA. The animation is made from 6 images taken over a 10-minute timespan. Each image was 30 second exposure, and the images were separated by 2 minutes.

The observed orbital arc of the asteroid now extends from Feb 15.93 to  Feb 24.58, or 8.5 days. Updated orbital elements from the MPC (MPEC 2015-D86, 26 Feb 2015):

Epoch 2014 Dec. 9.0 TT = JDT 2457000.5
M 298.05944              (2000.0)
n   0.84818796     Peri.  176.19408    T = 2457073.52693 JDT
a   1.1052859      Node   334.93169    q =     1.0044127
e   0.0912644      Incl.   15.06659    Earth MOID = 0.01553 AU
P   1.16           H   24.6
From 147 observations 2015 Feb. 15-24, mean residual 0".74.

13 observatories have now contributed to the observations, including our own MPC 461 Piszkéstetö where we discovered the object, and two observatories I used myself for 'remote' observations: MPC G68 Sierra Stars Observatory in the US and Q65 Warrumbungle observatory in Australia. The full list of contributing observatories (up to 24 Feb 2015) is:

461   Piszkéstetö Stn. (Konkoly), Hungary
J95   Great Shefford, UK
246   Klet obs. KLENOT, Czechia
J69   North observatory, Clanfield, UK
703   Catalina Sky Survey, USA
F65   Haleakala-Faulkes Telescope North, Hawaii, USA
C47   Nonndorf, Austria
G68   Sierra Stars Observatory, Markleeville, USA
474   Mount John Observatory, New Zealand
A48   Povegliano Veronese, Italy
B18   Terskol, Russia
Q65   Warrumbungle, Australia
W87  Cerro Tololo-LCOGT C, Chile

The asteroid is currently only observable from the southern hemisphere.

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