Electronic Telegram No. 5090 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 C/2022 A1 (SARNECZKY) Krisztian Sarneczky, Konkoly Observatory, reports the discovery of a fast-moving comet during a visual inspection of three stacked 104-s unfiltered CCD survey images taken at the Piszkesteto Observatory in Hungary on Jan. 2.1 UT with the 0.60-m Schmidt telescope (discovery observations tabulated below). The object shows a compact inner region (condensed false nucleus) about 8" x 10" in diameter and a fan-shaped tail at least 20" long in a westward direction. On a 312-s stacked image, there is a faint outer diffuse coma about 40" in diameter, with two jets in p.a. 230 and 350 deg. The red magnitude was 18.5 as measured within a circular aperture of radius 10". 2022 UT R.A. (2000) Decl. Mag. Observer Jan. 2.10924 9 06 28.99 +37 46 55.8 18.2 Sarneczky 2.10974 9 06 28.41 +37 46 54.8 18.1 " 2.11023 9 06 27.79 +37 46 52.8 18.0 " 2.11146 9 06 26.41 +37 46 49.8 18.0 " 2.11393 9 06 23.47 +37 46 43.2 18.3 " 2.12953 9 06 05.27 +37 46 01.5 18.1 " 2.13241 9 06 01.85 +37 45 53.8 18.3 " 2.13611 9 05 57.54 +37 45 44.2 18.2 " 2.13755 9 05 55.81 +37 45 39.5 18.3 " 2.14262 9 05 49.87 +37 45 26.3 18.2 " 2.14409 9 05 48.21 +37 45 22.3 18.4 " 2.14556 9 05 46.45 +37 45 18.8 18.5 " 2.15697 9 05 33.14 +37 44 47.5 18.5 " 2.15985 9 05 29.75 +37 44 40.1 18.4 " After the comet was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists have also reported on the cometary appearance. Forty-eight stacked 10-s exposures taken remotely on Jan. 3.5 UT by H. Sato, Tokyo, Japan, using a 0.43-m f/6.8 astrograph located near Mayhill, NM, USA, show a strongly condensed coma 12" in diameter with no tail; the magnitude was 18.2 as measured within a circular aperture of radius 7".6. L. Buzzi, Varese, Italy, writes that one-hundred stacked 20-s exposures taken on Jan. 3.14-3.16 with a 0.84-m f/3.5 reflector (and measured by A. Aletti) show this to be clearly a comet with a moderately condensed coma extending for 15". Forty-seven stacked 15-s exposures taken on Jan. 3.6 by K. Yoshimoto, Kumage, Yamaguchi, Japan, with a 0.20-m f/8 Ritchey-Chretien reflector show a faint coma 18" in diameter and of total mag 17.4; twenty stacked 15-s follow-up exposures taken remotely by Yoshimoto on Jan. 5.2 with a 0.43-m f/6.8 reflector near Mayhill, NM, USA, show a condensed coma 19" in diameter with total mag again 17.4. F. Kugel, Dauban, France, writes that forty-eight unfiltered exposures taken on Jan. 4.2 with a 0.4-m f/2.8 reflector show a 25" tail in p.a. 270 degrees. G. Galli, Pogliano Milanese, Italy, notes that exposures taken on Jan. 7.0 by S. Foglia and himself with a 0.36-m f/5.8 Schmidt-Cassegrain reflector show a diffuse 8" coma with no tail. The available astrometry appears on MPEC 2022-A59. The following parabolic orbital elements by S. Nakano (CBAT) are from 202 observations spanning Jan. 2-7 (mean residual 0".4). T = 2022 Jan. 31.12712 TT Peri. = 201.17388 Node = 285.52086 2000.0 q = 1.2529798 AU Incl. = 116.53264 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 18.5 and 2.5n = 8 (with several CCD astrometrists reporting the comet near mag 17). Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2021 12 12 11 52.63 +36 33.6 0.977 1.465 96.6 41.9 19.8 2021 12 17 11 38.13 +37 14.1 0.826 1.428 103.8 42.0 19.3 2021 12 22 11 14.73 +38 07.2 0.677 1.394 112.8 40.6 18.8 2021 12 27 10 35.27 +38 57.6 0.536 1.363 124.8 36.3 18.2 2022 01 01 09 26.97 +38 26.2 0.414 1.335 142.2 26.8 17.6 2022 01 03 08 48.64 +37 01.1 0.375 1.325 151.5 20.8 17.3 2022 01 05 08 04.62 +34 18.9 0.344 1.315 162.0 13.3 17.1 2022 01 07 07 17.64 +30 02.4 0.325 1.306 172.2 5.8 17.0 2022 01 09 06 31.70 +24 20.9 0.319 1.298 168.8 8.5 16.9 2022 01 11 05 50.32 +17 54.9 0.327 1.290 156.6 17.6 17.0 2022 01 13 05 15.27 +11 34.9 0.348 1.283 144.7 26.3 17.1 2022 01 15 04 46.62 +05 56.8 0.380 1.277 134.1 33.6 17.2 2022 01 17 04 23.56 +01 13.7 0.419 1.272 125.0 39.3 17.4 2022 01 19 04 05.06 -02 36.5 0.465 1.267 117.4 43.6 17.7 2022 01 21 03 50.14 -05 41.7 0.514 1.263 110.9 46.7 17.9 2022 01 26 03 23.80 -11 04.2 0.649 1.255 98.3 50.9 18.4 2022 01 31 03 07.33 -14 23.0 0.791 1.253 89.0 51.8 18.8 2022 02 05 02 56.57 -16 34.2 0.934 1.255 81.6 51.0 19.1 2022 02 10 02 49.36 -18 06.5 1.075 1.262 75.3 49.1 19.5 2022 02 15 02 44.47 -19 14.9 1.213 1.274 69.9 46.7 19.8 2022 02 20 02 41.20 -20 08.1 1.345 1.289 65.0 44.0 20.0 2022 02 25 02 39.09 -20 51.3 1.472 1.310 60.6 41.2 20.3 2022 03 02 02 37.88 -21 27.9 1.592 1.334 56.6 38.3 20.5 2022 03 07 02 37.37 -22 00.1 1.704 1.361 53.0 35.6 20.7 2022 03 12 02 37.41 -22 29.7 1.809 1.392 49.8 33.0 20.9 2022 03 17 02 37.90 -22 57.9 1.907 1.426 46.9 30.6 21.1 2022 03 22 02 38.76 -23 25.7 1.996 1.463 44.5 28.5 21.3 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 January 7 (CBET 5090) Daniel W. E. Green