Posts Tagged ‘ROCOT’

Recovery of comet P/2006 U1 (LINEAR)

L. Elenin / ISON-NM

January 14th, at the ISON-NM Observatory, we recovered a short-period comet of the Jupiter family – P/2006 U1 (LINEAR). The observations were made under the auspices of the ROCOT program. This is the second appearance of this comet; the last time its perihelion date was August 28, 2006.

On the images, the comet was off from the calculated coordinates by 9.2 arc minutes which was significant. At this moment, the comet is quickly approaching Earth, and will come within 0.775 a.u. on March 12-13, 2011. Its maximum brightness of mag. 17 will be in the first half of April. The comet’s period of revolution around the Sun is 4.63 years.

It is worth noting that Comet P/2006 U1 is a near-Earth object. The minimum distance at which its orbit crosses Earth’s orbit is 0.0526 a.u. (7.89 million km.). Taking into account its absolute magnitude M1 = 16.3, the comet could be considered a potentially hazardous object (PHO) if its MOID were less by just 0.0026 a.u.

The last time Comet P/2006 U1 was observed was about 4 years ago – January 13, 2007. In the near future it should receive its permanent number – 249P/LINEAR.

Below is shown the circular from the International Astronomical Union (IAU), dedicated to this event.

Circular No. 9194

Central Bureau for Astronomical Telegrams


New postal address:  Hoffman Lab 209; Harvard University;

20 Oxford St.; Cambridge, MA  02138; U.S.A.



Prepared using the Tamkin Foundation Computer Network

COMET P/2011 A4 = P/2006 U1 (LINEAR)

L. Elenin, Lyubertsy, Russia, reports his recovery of P/2006

U1 (cf. IAUC 8763) on images obtained remotely at the ISON-NM

Observatory near Mayhill, NM, USA; his astrometry is provided

below, and the object is described as slightly diffuse with no

visible tail.

2011 UT             R.A. (2000) Decl.       Mag.   Observer

Jan. 14.51322   14 14 00.58   -21 18 30.4   19.5   Elenin

14.52034   14 14 01.76   -21 18 36.5   19.3     “

14.52751   14 14 02.94   -21 18 43.5   19.7     “

15.46672   14 16 45.65   -21 32 55.8   19.3     “

15.49142   14 16 49.95    -21 33 18.1   19.4     “

15.51633   14 16 54.19    -21 33 41.2   19.1     “

The indicated correction to the prediction by S. Nakano (2010/2011

Comet Handbook) is Delta(T) = +0.24 day.  The following improved

elliptical elements by the undersigned are from 360 observations,

2006 Oct. 19-2011 Jan. 15 (mean residual 0″.46).

Epoch = 2011 Apr. 29.0 TT

T = 2011 Apr. 16.08061 TT        Peri. =  64.22882

e = 0.8160435                    Node  = 240.47143 2000.0

q = 0.5108788 AU                 Incl. =   8.42516

a =  2.7771717 AU   n = 0.21296095   P =   4.63 years

(C) Copyright 2011 CBAT

2011 January 17                (9194)            Daniel W. E. Green

Observation of P/2004 A1 (LONEOS) comet

The new attempt of observation P/2001 A1 (LONEOS) comet on 2-m FTN (Faulkes Telescope North). We taken 21 exposures by 30 seconds each. After stacking this images we obtain mag. limit about ~22m. The comet was not detected. P/2004 A1 located in very dense field, this factor complicate our surveying. At this time comet have ephemeris magnitude about 20.5m. P/2004 A1 (LONEOS) last observed on August 7 2007.

Another attempt to recovery P/1999 XN120

Within the bounds of ROCOT project, on April 6 and 7,  I was obtain observations of the P/1999 XN120 (Catalina). This short-period comet last observed on March 30 2000.

In the field of view I detected new unknown object, which moved parallel to predicted motion of  P/1999 XN120 (Catalina). All astrometric measurements from two nights was sended to MPC. After what, I receive answer from B. Marsden:

The observations on the two nights are mutually inconsistent with their being P/1999 XN120.

Proceeding from this opinion letter, I can state a fact what P/1999 XN120 (Catalina) at this time have magnitude less than 22.1m (with predicted magnitude about ~19.3m).

This observations obtained on Tenagra observatory with the 0.81-m f/7 Ritchey-Chretien telescope.

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