[Iaude] CBET 4897: COMET C/2020 X3

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 4897
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/2020 X3 (SOHO)
     K. Battams, Naval Research Laboratory, reports that Worachate Boonplod
(Samut Songkhram, Thailand) found an apparent Kreutz sungrazing comet in LASCO 
C3 coronagraph images taken with the SOHO spacecraft on Dec. 13.  Battam, who 
made the astrometric measurements (published on MPEC 2020-Y19), notes that 
the comet appeared stellar in C3 images, while C2 images show a condensed 
nuclear condensation with a short, faint tail (the comet reaching a peak 
apparent magnitude around 5.1 when entering the C2 field-of-view).  The comet 
faded rapidly towards the end of the observations (representative observations
are tabulated below).  Battams has also identified the comet in COR-2 images
obtained on Dec. 14 with the STEREO spacecraft that show the comet to be 
diffuse and elongated.

     2020 UT            R.A. (2000) Decl.       Mag.               
     Dec. 13.79602    17 29 12     -27 37.2     11.5
          13.82937    17 29 25     -27 30.8      8.0
          14.22936    17 32 06     -26 17.1      7.1
          14.34604    17 32 46     -25 53.7      6.6
          14.47936    17 33 28     -25 25.1      6.1
          14.65858    17 34 10     -24 43.1      5.5
          14.70857    17 34 18     -24 29.9      6.3
          14.73357    17 34 21     -24 23.2      7.0
          14.75023    17 34 22     -24 18.8      7.9

Several hours after Boonplod found the comet on SOHO images, the comet 
appeared with a tail in a composite photograph of the solar corona taken on
Dec. 14.7 UT by A. Moeller (Berlin, Germany) from Neuquen, Argentina, as
identified by Boonplod, who posted images of the comet from both sources at
URL https://drive.google.com/file/d/1pVXnBoN9Z1e8iMQkGSxbrCHx_GBTwAUw/view
(later linked to by D. Fischer, Koenigswinter, Germany, on the Facebook forum
"Solar Eclipse Chasers").  Battams also noted that the ground-based images of 
the comet during totality "look very much like those in C2" images.
     The following parabolic orbital elements by S. Nakano (CBAT) are from
81 observations spanning Dec. 13-14 (mean residual 8".4) and confirm the comet
as a Kreutz sungrazer.  It is possible that the comet did not survive 
perihelion (with absolute magnitude > 20).

     T = 2020 Dec. 14.9434 TT         Peri. =  75.8230
                                      Node  = 355.3637  2000.0
     q = 0.005038 AU                  Incl. = 144.0933


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2020 CBAT
2020 December 16                 (CBET 4897)              Daniel W. E. Green