[Iaude] CBET 5363: COMET C/2021 X2
quai at eps.harvard.edu
quai at eps.harvard.edu
Sat Mar 2 14:57:47 EST 2024
Electronic Telegram No. 5363
Central Bureau for Astronomical Telegrams
Mailing address: Hoffman Lab 209; Harvard University;
20 Oxford St.; Cambridge, MA 02138; U.S.A.
e-mail: cbatiau at eps.harvard.edu (alternate cbat at iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network
COMET C/2021 X2 (BOK)
An apparently asteroidal object with a nearly parabolic orbit that was
discovered on CCD images obtained on 2021 Dec. 1 with the 2.25 "Bok" reflector
at Kitt Peak as part of the Catalina Sky Survey, and which was announced as
A/2021 X2 on MPEC 2021-X227, has been found to show cometary appearance
elsewhere in 2021 and 2022.
2021 UT R.A. (2000) Decl. Mag.
Dec. 1.37798 5 13 10.91 +55 56 12.7 21.6
1.38287 5 13 09.79 +55 56 10.6 21.8
1.38773 5 13 08.73 +55 56 08.8
1.39260 5 13 07.60 +55 56 06.2 21.9
Thirty-second CCD images taken on 2021 Dec. 20.13-20.15 UT by R. A. Mastaler
(University of Arizona) with the Spacewatch/Steward Observatory Bok 2.3-m f/9
reflector (+ Tiffen/Wratten yellow filter; bandpass 515-950 nm) at Kitt Peak
in 0".8 seeing reveal a possible faint coma and no discernable tail; the
magnitude was given as 21.6-21.7. M. Micheli reported that CCD images taken
on 2022 Feb. 5.2 with the 3.6-m Canada-France-Hawaii Telescope by K. J. Meech,
E. Bufanda, J. Kleyna, and J. V. Keane (measured by Micheli and Kleyna) show a
2" coma and a tail about 5" long at p.a. 50 degrees; the magnitude was
measured to be 21.4-21.7.
Pre-discovery images of the comet as an apparently stellar object were
subsequently found in exposures obtained on 2021 Oct. 30.6 UT with the
Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala (magnitude measured
as 22.4-23.3) and on 2021 Nov. 8.6 with the Pan-STARRS2 1.8-m Ritchey-Chretien
reflector at Haleakala (mag 22.5-23.1). The available astrometry appears on
MPEC 2024-E8.
The following orbital elements by S. Nakano (Central Bureau) are from 94
observations spanning 2021 Oct. 30-2022 Nov. 23 (mean residual 0".5), with
corresponding "original" and "future" values of 1/a (with respect to the
solar-system barycenter) being +0.000022 and -0.000252 (+/- 0.000004) AU**-1,
respectively. The comet passed 2.57 AU from Jupiter on 2022 Oct. 28 UT.
Epoch = 2022 June 30.0 TT
T = 2022 July 8.15660 TT Peri. = 193.28399
e = 1.0013243 Node = 228.79820 2000.0
q = 2.9945481 AU Incl. = 137.14414
The comet is now too faint to be observed easily, at r = 6.2 AU, according
to photometric power-law parameters H = 14.0 and 2.5n = 8.
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2024 CBAT
2024 March 2 (CBET 5363) Daniel W. E. Green
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