As C/2023 A3 (Tsuchinshan-ATLAS) fades from 9th to 11th magnitude in the evening sky, three other comets are expected to be brighter than magnitude 12 as 2024 comes to a close. Like Tsuchinshan-ATLAS, two are also limited to northern hemisphere observers, while the other is only for southern hemisphere observers.

333P/LINEAR is a short-period comet with an 8.7-year orbital period and should peak a little brighter than magnitude 10 as it races across the northern sky. The comet won’t stay bright for long and will have faded to around magnitude 12 by the end of the month. The other northern comet, C/2022 E2 (ATLAS), will barely break the 12th magnitude barrier this month before also fading by the end of the month. 

In the southern hemisphere, C/2024 G3 (ATLAS) should rapidly brighten from around magnitude 9th to 5th magnitude. Unfortunately, it will be a horizon-hugger this month. ATLAS is still brightening at a pace that suggests it will become a negative magnitude object at perihelion in January, though it will be too close to the Sun to be seen by most observers at that time. By the time G3 climbs back into a dark sky, it will be much fainter, though possibly still a naked-eye object.

The monthly ALPO Comet News PDF can be found here. All are encouraged to join the discussion over at Cloudy Nights.

C/2023 A3 (Tsuchinshan-ATLAS) did not disappoint last month. After reaching a brilliant peak at magnitude -3 to -4, though it was only within a few degrees of the Sun at the time, the comet reappeared in the evening sky at around 0^th magnitude. Though it quickly faded as it moved higher in the sky, a tail up to 20 degrees in length was visually observed. Imagers also detected the predicted anti-tail. Tsuchinshan-ATLAS starts November in the evening sky at 6^th magnitude. Since it is moving away from the Earth and Sun, it will continue to fade and should be around magnitude 9 at the end of the month. 

November will be the last month to see 13P/Olbers visually as it approaches solar conjunction. Northern hemisphere observers may be able to observe short-period comet 333P/LINEAR, which may reach 10^th magnitude at the end of the month in the morning sky. While 333P/LINEAR will be a low-elevation object for southern hemisphere observers, they will have C/2024 G3 (ATLAS) to themselves. C/2024 G3 comes to perihelion in January at a close 0.09 au from the Sun. Though it will be located very close to the Sun when at its brightest, there is an outside chance that this could be a nice object from the southern hemisphere after its perihelion.

The monthly ALPO Comet News PDF can be found here. All are encouraged to join the discussion over at Cloudy Nights.

Last month, the ALPO Comets Section received 120 images and 139 magnitude estimates of 36 comets: C/2024 S1 (ATLAS), C/2024 Q3 (PANSTARRS), C/2024 G3 (ATLAS), C/2024 B1 (Lemmon), C/2023 V4 (Camarasa-Duszanowicz), C/2023 TD22 (Lemmon), C/2023 R1 (PANSTARRS), C/2023 C2 (ATLAS), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 U1 (Leonard), C/2022 N2 (PANSTARRS), C/2022 E2 (ATLAS), C/2021 S3 (PANSTARRS), C/2020 V2 (ZTF), P/2024 Q2 = P/2005 SB216 (LONEOS), P/2010 WK (LINEAR), 384P/Kowalski, 360P/WISE, 328P/LONEOS-Tucker, 305P/Skiff, 253P/PANSTARRS, 229P/Gibbs, 208P/McMillan, 190P/Mueller, 154P/Brewington, 146P/Shoemaker-Levy, 136P/Mueller, 130P/McNaught-Hughes, 89P/Russell, 54P/de Vico-Swift-NEAT, 50P/Arend, 49P/Arend-Riguax, 43P/Wolf-Harrington, 37P/Forbes, 13P/Olbers, and 12P/Pons-Brooks. 

A big thanks to our recent contributors: Dan Bartlett, José J. Chambó, Dan Crowson, Michel Deconinck, Jose Guilherme de Souza Aguiar, Juan Jose Gonzalez Suarez, Christian Harder, Eliot Herman, Rik Hill, Michael Jäger, John Maikner, Gianluca Masi, Michael Mattiazzo, Martin Mobberley, Mike Olason, Andrew Pearce, Chris Schur, Tenho Tuomi, and Christopher Wyatt.

The monthly ALPO Comet News PDF can be found Cloudy Nights forum. All are encouraged to join the discussion over at Cloudy Nights.