[Iaude] CBET 5360: COMET P/2005 XR_132

[quai at eps.harvard.edu]

                                                  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 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 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