March will be all about comet 12P/Pons-Brooks, at least for those of us in the northern hemisphere. While the comet will be at perihelion and a bit brighter and more active in April, March will be the last month to observe the comet in a dark sky at a reasonable elevation. The comet starts March at 6th magnitude and could be as bright as 4th magnitude by the end of the month. I suspect that observers under a dark sky will report naked-eye observations. The comet is also proving to be very photogenic with a multi-degree long gas tail already easily imaged.

Pons-Brooks isn’t the only comet to observe in March. The following will be visible from both hemispheres. In the evening sky, we have 144P/Kushida fading from 9th to 11th magnitude. 12P/Pons-Brooks isn’t the only Halley-family comet in the evening sky. 13P/Olbers will be visible brightening from 11th to 10th magnitude.

Near opposition, 62P/Tsuchinshan will be fading from 10th to 13th magnitude. The morning sky sees two reasonably bright long-period comets; C/2021 S3 (PANSTARRS) will be around 9th magnitude, and incoming C/2023 A3 (Tsuchinshan-ATLAS) will brighten from 12th to 11th magnitude.

Last month, the ALPO Comets Section received 147 images and 71 magnitude estimates of 30 comets: C/2024 B2 (Lemmon), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 E2 (ATLAS), C/2021 T4 (Lemmon), C/2021 S3 (PANSTARRS), C/2021 G2 (ATLAS), C/2020 V2 (ZTF), C/2020 S4 (PANSTARRS), C/2020 K1 (PANSTARRS), C/2019 U5 (PANSTARRS), C/2017 K2 (PANSTARRS), 479P/Elenin, 475P/Spacewatch-LINEAR, 473P/NEAT, 244P/Scotti, 234P/LINEAR, 227P/Catalina-LINEAR, 216P/LINEAR, 207P/NEAT, 150P/LONEOS, 144P/Kushida, 121P/Shoemaker-Holt, 103P/Hartley, 65P/Gunn, 62P/Tsuchinshan, 37P/Forbes, 32P/Comas Sola, 29P/Schwassmann-Wachmann, 13P/Olbers, and 12P/Pons-Brooks.

A big thanks to our recent contributors: Dan Bartlett, Michel Besson, Denis Buczynski, Dan Crowson, Michel Deconinck, Jose Guilherme de Souza Aguiar, Juan Jose Gonzalez Suarez, Eliot Herman, Michael Jäger, Christian Harder, Manos Kardasis, John Maikner, Gianluca Masi, Erwin Matys, Martin Mobberley, Karoline Mrazek, Mike Olason, Uwe Pilz, Greg Ruppel, Chris Schur, Gregory T. Shanos, Willian Souza, Tenho Tuomi, Russell Wheeler, and Christopher Wyatt.

The monthly ALPO Comet News PDF can be found here. A shorter version of this report is posted on a dedicated Cloudy Nights forum. All are encouraged to join the discussion over at Cloudy Nights.

The comet of the month continues to be 12P/Pons-Brooks. Returning for the first time since 1954, Pons-Brooks has been delighting observers with a constant series of outbursts. While the object is currently only visible to northern observers, those who can see it will be able to watch it brighten from around magnitude 7.7 to 6.4 in the evening sky. Joining Pons-Brooks in the evening sky is another Halley-type comet, 13P/Olbers, making its first return since 1956. Olbers is also brightening but still faint at 11-12th magnitude this month. Closing out the evening comets is short-period 144P/Kushida, which was predicted to reach 8th magnitude but appears to have peaked at 10th magnitude.

In the morning sky are two comets, which should be at 9th magnitude, 62P/Tsuchinshan and C/2021 S3 (PANSTARRS). Also, in the morning is C/2023 A3 (Tsuchinshan-ATLAS), which could become a bright object later in the year and is now within visual range of large aperture telescopes at 12th magnitude.

Last month, the ALPO Comets Section received 146 images and 102 magnitude estimates of 30 comets: P/2023 S1, C/2023 H5 (Lemmon), C/2023 H2 (Lemmon), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 QE78 (ATLAS), C/2022 L2 (ATLAS), C/2022 E2 (ATLAS), C/2021 S3 (PANSTARRS), C/2021 G2 (ATLAS), C/2020 V2 (ZTF), C/2020 K1 (PANSTARRS), C/2019 U5 (PANSTARRS), C/2017 K2 (PANSTARRS), 227P/Catalina-LINEAR, 226P/Pigott-LINEAR-Kowalski, 216P/LINEAR, 207P/NEAT, 194P/LINEAR, 176P/LINEAR, 170P/Christensen, 150P/LONEOS, 144P/Kushida, 126P/IRAS, 105P/Singer Brewster, 103P/Hartley, 62P/Tsuchinshan, 39P/Oterma, 32P/Comas Sola, 29P/Schwassmann-Wachmann, 13P/Olbers, and 12P/Pons-Brooks.

A big thanks to our recent contributors: Denis Buczynski, Dan Crowson, Michel Deconinck, Jose Guilherme de Souza Aguiar, Juan Jose Gonzalez Suarez, Eliot Herman, Michael Jäger, Christian Harder, Manos Kardasis, John Maikner, Gianluca Masi, Erwin Matys, Martin Mobberley, Karoline Mrazek, Mike Olason, Uwe Pilz, Greg Ruppel, Chris Schur, Gregory T. Shanos, Willian Souza, and Christopher Wyatt.

The monthly ALPO Comet News PDF can be found here. A shorter version of this report is posted on a dedicated Cloudy Nights forum. All are encouraged to join the discussion over at Cloudy Nights.

Happy New Year! The start of 2024 sees the action dominated by returning comets. The brightest comet of the month should be the Halley-family comet 12P/Pons-Brooks, which is returning for the first time since 1954 and will brighten to 7th magnitude by the end of January. 12P has experienced a number of major outbursts, which recently seem to be occurring at a two-week cadence. Sharing the evening sky with 12P is short-period comet 144P/Kushida brightening to 8th magnitude. Also around 8th magnitude, but in the morning sky, is short-period comet 62P/Tsuchinshan. The only relatively bright long-period comet is C/2021 S3 (PANSTARRS), which may reach 9th magnitude and is in the morning sky before dawn.

Last month, the ALPO Comets Section received 131 images and 105 magnitude estimates of 33 comets: C/2023 X2 (Lemmon), C/2023 X1 (Leonard), C/2023 T3 (Fuls), C/2023 S3 (Lemmon), C/2023 P1 (Nishimura), C/2023 H2 (Lemmon), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 QE78 (ATLAS), C/2022 JK5 (PANSTARRS), C/2022 E2 (ATLAS), C/2021 X1 (Maury-Attard), C/2021 S3 (PANSTARRS), C/2021 G2 (ATLAS), C/2021 A9 (PANSTARRS), C/2020 V2 (ZTF), C/2020 K1 (PANSTARRS), C/2019 U5 (PANSTARRS), C/2017 K2 (PANSTARRS), 471P, 470P/PANSTARRS, 378P/McNaught, 226P/Pigott-LINEAR-Kowalski, 207P/NEAT, 170P/Christensen, 144P/Kushida, 126P/IRAS, 103P/Hartley, 62P/Tsuchinshan, 32P/Comas Sola, 30P/Reinmuth, 29P/Schwassmann-Wachmann, 13P/Olbers, and 12P/Pons-Brooks.

A big thanks to our recent contributors: Dan Bartlett, Todd Bossaller, Denis Buczynski, Dan Crowson, Michel Deconinck, J. J. Gonzalez Suarez, Christian Harder, Carl Hergenrother, Eliot Herman, Michael Jäger, Manos Kardasis, Martin Mobberley, Mike Olason, Uwe Pilz, Greg Ruppel, Chris Schur, Gregory T. Shanos, Willian Souza, Tenho Tuomi, and Chris Wyatt.

The monthly ALPO Comet News PDF can be found here. A shorter version of this report is posted on a dedicated Cloudy Nights forum. All are encouraged to join the discussion over at Cloudy Nights.

2023 ends with several comets brighter than magnitude 10. The most newsworthy is inbound Halley-type comet 12P/Pons-Brooks. Though still months from its April perihelion, its major outbursts have brightened it to 8-9th magnitude. Northern observers can catch 12P in the evening sky. Southern observers will be able to watch another evening comet as C/2023 H2 (Lemmon) rapidly fades from 9th to 12th magnitude after its close approach to Earth last month. 

In the morning sky, 62P/Tsuchinshan will peak at around 8th magnitude while 103P/Hartley will be fading from 9th to 11th magnitude. Two other comets, 144P/Kushida and C/2021 S3 (PANSTARRS), will be brightening this month, with both around magnitude 10 by New Year’s and still brightening into 2024. 

On December 9 at 35.14 au, comet 1P/Halley arrives at aphelion. The comet will now start its long trek to its next perihelion in 2061!

Last month, the ALPO Comets Section received 187 observations of comets C/2023 P1 (Nishimura), C/2023 V5 (Leonard), P/2023 S1, C/2023 H2 (Lemmon), C/2022 U3 (Bok), C/2022 QE78 (ATLAS), C/2022 E2 (ATLAS), C/2020 V2 (ZTF), C/2017 K2 (PANSTARRS), 12P/Pons-Brooks, 13P/Olbers, 29P/Schwassmann-Wachmann, 32P/Comas Sola, 62P/Tsuchinshan, 103P/Hartley, 143P/Kowal-Mrkos, 144P/Kushida, 170P/Christensen, 195P/Hill, 209P/LINEAR, 227P/Catalina-LINEAR, 246P/NEAT, 310P/Hill, 404P/Bressi, and 465P/Hill.

A big thanks to our recent contributors: Dan Bartlett, Denis Buczynski, Jose Guilherme de Souza Aguiar, Jef de Wit, Michel Deconinck, J. J. Gonzalez Suarez, Christian Harder, Carl Hergenrother, Eliot Herman, Michael Jäger, John Maikner, Martin Mobberley, Efrain Morales Rivera, Mike Olason, Uwe Pilz, Michael Rosolina, Greg Ruppel, Chris Schur, Willian Souza, Tenho Tuomi, and Chris Wyatt.

The monthly ALPO Comet News PDF can be found here. A shorter version of this report is posted on a dedicated Cloudy Nights forum. All are encouraged to join the discussion over at Cloudy Nights.

November sees several comets within range of small apertures. C/2023 H2 (Lemmon) will pass 0.19 au from Earth this month, possibly brightening to around 6-7th magnitude as it flies across the evening sky from Ursa Major to Grus. In the morning sky, two short-period comets are on display: 62P/Tsuchinshan as it brightens from 10th to 8th magnitude and 103P/Hartley fading from 8th to 9th magnitude.

A little fainter is inbound Halley-type comet 12P/Pons-Brooks, now being hyped in the press as the “Devil Comet.” As was the case during its last two returns in 1884 and 1954, Pons-Brooks is experiencing a series of outbursts, with the most recent major outburst occurring on October 31/November 1. November will see this northern evening comet brightening from 11th to 10th magnitude.

Last month the ALPO Comets Section received 202 observations of comets C/2023 S2 (ATLAS), C/2023 H2 (Lemmon), C/2023 E1 (ATLAS), C/2022 JK5 (PANSTARRS), C/2022 A2 (PANSTARRS), C/2021 X1 (Maury-Attard), C/2021 S4 (Tsuchinshan), C/2021 S3 (PANSTARRS), C/2020 V2 (ZTF), C/2020 K1 (PANSTARRS), C/2018 A6 (Gibbs), C/2017 K2 (PANSTARRS), 471P/2010 YK3, 358P/PANSTARRS , 279P/La Sagra, 225P/LINEAR, 212P/NEAT, 207P/NEAT, 170P/Christensen, 144P/Kushida, 126P/IRAS, 103P/Hartley, 62P/Tsuchinshan, 32P/Comas Sola, 30P/Reinmuth, 30P/Reinmuth, 29P/Schwassmann-Wachmann, 12P/Pons-Brooks, and 2P/Encke. 

A big thanks to our August contributors: Dan Bartlett, Michel Besson, Denis Buczynski, Dan Crowson, Jose Guilherme de Souza Aguiar, Michel Deconinck, J. J. Gonzalez Suarez, Christian Harder, Carl Hergenrother, Eliot Herman, Michael Jäger, Manos Kardasis, John Maikner, Gianluca Masi, Martin Mobberley, Philippe Morel, Mike Olason, Uwe Pilz, Greg Ruppel, Chris Schur, Tenho Tuomi, and Chris Wyatt.

The monthly ALPO Comet News PDF can be found here. A shorter version of this report is posted on a dedicated Cloudy Nights forum. All are encouraged to join the discussion over at Cloudy Nights.