Electronic Telegram No. 5360 Central Bureau for Astronomical Telegrams Mailing address: Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network COMET P/2005 XR_132 (SPACEWATCH) An apparently asteroidal object discovered four times by the Spacewatch survey, with four separate dates in the Minor Planet Center's "isolated tracklet file", had those separate dates identified several years ago as a single object under the minor-planet designation 2005 XR_132 (cf. MPS 1209835, dated 2020 July 28; and MPC 123589, dated 2020 Aug. 7); those observations are tabulated below. This object has subsequently been found by observers elsewhere to show cometary activity. 2005 UT R.A. (2000) Decl. Mag. Dec. 5.46865 7 11 13.16 +20 52 32.1 20.5 5.48601 7 11 12.66 +20 52 24.8 20.6 5.50339 7 11 12.21 +20 52 17.6 20.6 27.22516 6 55 48.38 +18 16 12.2 27.24250 6 55 47.38 +18 16 04.7 27.25982 6 55 46.39 +18 15 57.1 2012 UT R.A. (2000) Decl. Mag. Nov. 13.25945 4 33 53.41 +29 55 25.8 21.7 13.27744 4 33 52.56 +29 55 21.6 21.5 13.29884 4 33 51.60 +29 55 15.3 21.5 22.26242 4 26 25.11 +29 10 17.8 21.3 22.28011 4 26 24.20 +29 10 11.8 20.7 22.29779 4 26 23.16 +29 10 05.8 21.1 P. Veres, MPC, informs the Bureau that Y.-C. Cheng informed the MPC on 2021 Apr. 6 that four 480-s R-band images of 2005 XR_132 taken on 2021 Apr. 5.6 UT with the Lulin 1-m telescope in Taiwan showed a fan-shaped tail along the anti-solar direction, spanning p.a. 30-60 degrees; the total magnitude was around 19.8. Also, M. Kelley informed the MPC on 2021 Apr. 14 that, while the head appeared stellar, there was a straight 10" tail spanning p.a. 290-335 degrees on images obtained on 2021 Feb. 8.5 with the 1.2-m Schmidt telescope at Palomar. Additional Palomar observations reported by Kelley that were taken on 2021 Feb. 10.4 show a 7" tail in p.a. 285-320 degrees. Following Cheng's posting of his observations online, other observers reported their own confirmation of cometary activity to the Bureau. L. Buzzi, Varese, Italy, obtained one-hundred 30-s CCD exposures of 2005 XR_132 on 2021 Apr. 7.9 UT with a 0.84-m f/3.5 reflector, which show clear evidence of a short, broad tail 7" long in p.a. 36 degrees. Twelve stacked 60-s CCD exposures taken remotely on 2021 Apr. 11.4 with a 0.51-m f/6.8 astrograph located at Siding Spring, NSW, Australia, by H. Sato (Bunkyo-ku, Tokyo, Japan) show a strongly condensed coma 8" in diameter with a hint of tail northward; the magnitude was 19.0 as measured within a circular aperture of radius 6".6. Additional astrometry appears on MPEC 2024-D135. The following orbital elements by S. Nakano (Central Bureau) are from 110 observations spanning 2005 Dec. 5-2021 May 14 (mean residual 0".4). The comet passed 0.77 AU from Jupiter on 2008 Sept. 10 UT. Epoch = 2006 May 25.0 TT T = 2006 May 16.84264 TT Peri. = 238.11049 e = 0.4218117 Node = 270.47557 2000.0 q = 2.1704165 AU Incl. = 15.70731 a = 3.7538231 AU n = 0.13551687 P = 7.27 years Epoch = 2013 Aug. 16.0 TT T = 2013 Aug. 11.28404 TT Peri. = 240.82749 e = 0.4336945 Node = 265.46614 2000.0 q = 2.1272255 AU Incl. = 14.48383 a = 3.7563212 AU n = 0.13538171 P = 7.28 years Epoch = 2020 Nov. 7.0 TT T = 2020 Nov. 26.95550 TT Peri. = 240.92175 e = 0.4322784 Node = 265.39608 2000.0 q = 2.1372926 AU Incl. = 14.46847 a = 3.7646843 AU n = 0.13493084 P = 7.30 years Epoch = 2028 Mar. 10.0 TT T = 2028 Mar. 10.52852 TT Peri. = 240.94746 e = 0.4336750 Node = 265.33613 2000.0 q = 2.1268054 AU Incl. = 14.47622 a = 3.7554502 AU n = 0.13542881 P = 7.28 years Epoch = 2035 June 2.0 TT T = 2035 June 10.92728 TT Peri. = 240.91152 e = 0.4356644 Node = 265.19931 2000.0 q = 2.1138421 AU Incl. = 14.49443 a = 3.7457182 AU n = 0.13595696 P = 7.25 years The comet's brightness has generally followed photometric power-law parameters H = 15.5 and 2.5n = 8. It is now far too faint for normal observation. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2024 CBAT 2024 February 29 (CBET 5360) Daniel W. E. Green