Electronic Telegram No. 5136 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 L2 (ATLAS) P. Veres, Minor Planet Center, reports that A. Fitzsimmons notified the MPC on June 10 of the discovery of an apparent new comet on four 30-s CCD images taken with a 0.5-m f/2 Schmidt reflector at Mauna Loa, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program, with Fitzsimmons describing the object's image as "soft" with an apparent coma of size 8" (full-width-at-half-maximum) in 6".0 seeing, adding that background objects made the observation difficult. The discovery observations are tabulated below. 2022 UT R.A. (2000) Decl. Mag. June 10.47539 19 29 56.35 +34 30 14.6 18.4 10.47724 19 29 56.37 +34 30 15.3 18.3 10.48000 19 29 56.11 +34 30 16.2 18.3 10.48810 19 29 55.73 +34 30 17.4 18.5 After the object was posted on the MPC's PCCP webpage, other CCD astrometrists have confirmed the cometary appearance. Six stacked 120-s exposures taken remotely by H. Sato (Tokyo, Japan) with a 0.43-m f/6.8 astrograph located at Mayhill, NM, USA, on June 11.42 UT show a strongly condensed coma 8" in diameter and no tail; the magnitude was 18.7 as measured within a circular aperture of radius 5".7. A. Valvasori, Padulle, Italy, writes that forty-nine stacked 120-s unfiltered exposures taken remotely by E. Guido and himself with a 0.30-m f/4 reflector at the ALMO Observatory in Padulle on June 11.9 show a coma about 10" in diameter of mag 18.3. E. Guido, Castellammare di Stabia, Italy, writes that twenty-five 90-s unfiltered exposures obtained remotely by a large group of observers using a "Telescope Live" 0.7 m f/8 Ritchey-Chretien reflector at Oria, Spain, on June 12.0 show a diffuse coma about 7" in diameter of mag 18.5-18.6. Twenty stacked 120-s unfiltered exposures taken on June 13.93-14.00 by E. Bryssinck, Kruibeke, Belgium, with a 0.4-m f/3.8 reflector in poor conditions show a central condensation with a coma of size 8" and no tail in a dense starfield. The available astrometry appears on MPEC 2022-M18. The following parabolic orbital elements by S. Nakano (Central Bureau) are from 173 observations spanning June 10-20 (mean residual 0".5). T = 2024 Mar. 17.23231 TT Peri. = 198.63714 Node = 38.70167 2000.0 q = 2.7567140 AU Incl. = 129.36779 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 8.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 05 21 19 45.35 +33 07.9 6.417 6.712 102.6 8.5 18.7 2022 05 31 19 38.54 +33 53.4 6.248 6.640 108.5 8.3 18.6 2022 06 10 19 30.36 +34 28.9 6.092 6.567 113.8 8.1 18.5 2022 06 20 19 20.98 +34 51.3 5.954 6.495 118.1 7.9 18.4 2022 06 30 19 10.65 +34 58.1 5.837 6.423 121.2 7.8 18.3 2022 07 10 18 59.75 +34 47.2 5.742 6.350 122.8 7.7 18.2 2022 07 20 18 48.71 +34 17.8 5.670 6.277 122.7 7.8 18.2 2022 07 30 18 37.99 +33 30.3 5.623 6.205 120.8 8.1 18.1 2022 08 09 18 28.00 +32 26.2 5.600 6.132 117.3 8.4 18.0 2022 08 19 18 19.11 +31 08.4 5.598 6.059 112.6 8.9 18.0 2022 08 29 18 11.53 +29 40.1 5.615 5.986 106.8 9.3 18.0 2022 09 08 18 05.44 +28 05.0 5.647 5.913 100.4 9.6 17.9 2022 09 18 18 00.84 +26 26.7 5.690 5.840 93.6 9.9 17.9 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 June 20 (CBET 5136) Daniel W. E. Green