This month’s ALPO Comet News will be another short one. Again, other commitments are vying for my time, and only four comets are expected to be brighter than magnitude 12 this month.

Northern hemisphere observers will be able to watch two fading comets, 13P/Olbers fade from 7th to 8th magnitude and C/2023 V4 (Camarasa-Duszanowicz) from 11th to 13th. Southern hemisphere observers will be able to observe 12P/Pons-Brooks fade from 9th to 10th magnitude. Southern observers will also be able to catch C/2023 A3 (Tsuchinshan-ATLAS) brighten from 8th to 7th magnitude before losing it to the glare of twilight around mid-month.

Last month, the ALPO Comets Section received 247 images and 164 magnitude estimates of 44 comets: 12P/Pons-Brooks, 13P/Olbers, 21P/Giacobini-Zinner, 29P/Schwassmann-Wachmann, 32P/Comas Sola, 37P/Forbes, 62P/Tsuchinshan, 65P/Gunn, 89P/Russell, 125P/Spacewatch, 130P/McNaught-Hughes, 144P/Kushida, 146P/Shoemaker-LINEAR, 154P/Brewington, 208P/McMillan, 227P/Catalina-LINEAR, 236P/LINEAR, 251P/LINEAR, 253P/PANSTARRS, 299P/Catalina-PANSTARRS, 468P/Siding Spring, C/2017 K2 (PANSTARRS), C/2019 O3 (Palomar), C/2019 T4 (ATLAS), C/2019 U5 (PANSTARRS), C/2020 K1 (PANSTARRS), C/2020 V2 (ZTF), C/2021 G2 (ATLAS), C/2021 S3 (PANSTARRS), C/2021 X1 (Maury-Attard), C/2022 E2 (ATLAS), C/2022 L2 (ATLAS), C/2022 N2 (PANSTARRS), C/2022 U1 (Leonard), C/2023 A3 (Tsuchinshan-ATLAS), C/2023 C2 (ATLAS), C/2023 V4 (Camarasa-Duszanowicz), C/2023 X1 (Leonard), C/2024 A2 (ATLAS), C/2024 C4 (ATLAS), C/2024 E1 (Wierzchos), C/2024 F2 (PANSTARRS), C/2024 G1 (Wierzchos), C/2024 G3 (ATLAS), and C/2024 J1 (Wierzchos).

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, Uwe Pilz, Chris Schur, Greg T. Shanos, Tenho Tuomi, 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.

This month’s ALPO Comet News will be shorter than usual. This is partly due to other commitments vying for my time and the fact that only four comets are expected to be brighter than magnitude 12 this month.

Halley-type comet 13P/Olbers will be the brightest comet of the month. Early July should see Olbers peak at around magnitude 6.6, and it will only be a few tenths of a magnitude fainter at the end of the month. It is only visible from the northern hemisphere low in the western evening sky. Joining Olbers in the evening sky for northern observers is C/2023 V4 (Camarasa-Duszanowicz), which should fade from 11th to 13th magnitude.

Southern observers will be able to observe the other returning Halley-type comet, 12P/Pons-Brooks. Now over two months past perihelion, Pons-Brooks is still experiencing outbursts, though fading from magnitude 8.0 to almost 10 in July.

C/2023 A3 (Tsuchinshan-ATLAS) will be the main comet story for the remainder of 2024. Unfortunately, the comet continues its intrinsic fading that started around May 1st. Northern hemisphere observers will only be able to observe the comet through mid-July. Southern hemisphere observers will be able to follow the comet into August.

Last month, the ALPO Comets Section received 110 images and 95 magnitude estimates of 25 comets: C/2024 J1 (Wierzchos), C/2024 G3 (ATLAS), C/2024 G1 (Wierzchos), C/2024 F2 (PANSTARRS), C/2024 C4 (ATLAS), C/2024 A2 (ATLAS), C/2023 X1 (Leonard), C/2023 V4 (Camarasa-Duszanowicz), C/2023 C2 (ATLAS), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 L2 (ATLAS), C/2022 E2 (ATLAS), C/2021 S3 (PANSTARRS), C/2021 G2 (ATLAS), C/2019 U5 (PANSTARRS), C/2017 K2 (PANSTARRS), 227P/Catalina-LINEAR, 154P/Brewington, 144P/Kushida, 62P/Tsuchinshan, 32P/Comas Sola, 29P/Schwassmann-Wachmann, 144P/Kushida, 13P/Olbers, and 12P/Pons-Brooks.

A big thanks to our recent contributors: Dan Bartlett, Dan Crowson, José J. Chambó, Jose Guilherme de Souza Aguiar, J. J. Gonzalez Suarez, Christian Harder, Carl Hergenrother, Eliot Herman, Rik Hill, Michael Jäger, John Maikner, Gianluca Masi, Michael Mattiazzo, Martin Mobberley, Mike Olason, Uwe Pilz, Gregg Ruppel, Chris Schur, Willian Souza, 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.

This month, the theme will be anti-tails as the Earth passes through the orbital planes of our two returning Halley-type comets. Images are already showing 12P/Pons-Brooks’ strong anti-tail, which will only get stronger as we approach the orbital plane crossing on June 7. 13P/Olbers will probably have a weaker anti-tail, but one should still be visible as we approach its orbital plane crossing on June 17. 

At the start of June, Pons-Brooks will be the brightest comet in the sky, though it is only visible to southern observers. As the month progresses, it will fade to 8th magnitude and hand the title of brightest comet in the sky to Olbers which will brighten from 7th to 6th magnitude this month. Unlike Pons-Brooks, Olbers will be visible at northern latitudes but not at southern mid-latitudes.

The other big news comet is C/2023 A3 (Tsuchinshan-ATLAS). This comet has the potential to be a bright object this October but has recently undergone a fading over the past month or so. This doesn’t mean the comet is breaking up, at least not yet, but it does suggest caution with any predictions about its brightness going forward. Like many long-period comets, we’ll have to wait and see with Tsuchinshan-ATLAS. It will be visible to observers in both hemispheres in June and “should” brighten from 10th to 9th magnitude in the evening sky.

Three other comets are expected to be between magnitude 10 and 12. 479P/Elenin and C/2023 V4 (Camarasa-Duszanowicz) are in the evening sky, and C/2021 S3 (PANSTARRS) is in the morning sky, though Camarasa-Duszanowicz and PANSTARRS are only visible from the northern hemisphere.

Last month, the ALPO Comets Section received 128 images and 246 magnitude estimates of 25 comets: C/2024 F2 (PANSTARRS), C/2023 V4 (Camarasa-Duszanowicz), C/2023 C2 (ATLAS), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 L2 (ATLAS), C/2022 E2 (ATLAS), C/2021 S3 (PANSTARRS), C/2021 G2 (ATLAS), C/2020 K1 (PANSTARRS), C/2019 U5 (PANSTARRS), C/2017 K2 (PANSTARRS), P/2020 WJ5 (Lemmon), 479P/Elenin, 362P/(457175) 2008 GO98, 349P/Lemmon, 251P/LINEAR, 217P/LINEAR, 209P/LINEAR, 144P/Kushida, 65P/Gunn, 62P/Tsuchinshan, 32P/Comas Sola, 29P/Schwassmann-Wachmann, 13P/Olbers, and 12P/Pons-Brooks.

A big thanks to our recent contributors: Salvador Aguirre, Dan Bartlett, Dan Crowson, José J. Chambó, Jose Guilherme de Souza Aguiar, J. J. Gonzalez Suarez, Christian Harder, Carl Hergenrother, Eliot Herman, Rik Hill, Michael Jäger, John Maikner, Gianluca Masi, Michael Mattiazzo, Mike Olason, Ludovic Perbet, Uwe Pilz, Michael Rosolina, Gregg Ruppel, Chris Schur, Greg 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.

This month, the theme will be anti-tails as the Earth passes through the orbital planes of our two returning Halley-type comets. Images are already showing 12P/Pons-Brooks’ strong anti-tail, which will only get stronger as we approach the orbital plane crossing on June 7. 13P/Olbers will probably have a weaker anti-tail, but one should still be visible as we approach its orbital plane crossing on June 17. 

12P/Pons-Brooks reached its peak performance last month for northern hemisphere observers. The comet is still a 4th magnitude object as May begins but is only observable from the southern hemisphere, fading from 4th to 6th magnitude in the evening sky. 

Northern observers currently have another Halley-type comet to themselves, as 13P/Olbers brightens from 8th to 7th magnitude in the evening sky. C/2023 A3 (Tsuchinshan-ATLAS) is observable by all in the evening sky as it continues brightening at 9th magnitude.

Two fainter objects between 10th and 12th magnitude are also visible. 479P/Elenin is having its best apparition in any of our lifetimes and should be at 10th to 11th magnitude in the evening sky. While in the morning sky, C/2021 S3 (PANSTARRS) is fading from 10th to 11th magnitude.

Last month, the ALPO Comets Section received 202 images and 109 magnitude estimates of 25 comets: C/2024 G1 (Wierzchos), C/2024 F2 (PANSTARRS), C/2024 C4 (ATLAS), C/2023 S3 (Lemmon), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 L2 (ATLAS), C/2022 E2 (ATLAS), C/2021 S3 (PANSTARRS), C/2021 G2 (ATLAS), C/2020 S4 (PANSTARRS), C/2020 K1 (PANSTARRS), C/2019 U5 (PANSTARRS), C/2017 K2 (PANSTARRS), 479P/Elenin, 362P/(457175) 2008 GO98, 227P/Catalina-LINEAR, 144P/Kushida, 125P/Spacewatch, 65P/Gunn, 62P/Tsuchinshan, 37P/Forbes, 32P/Comas Sola, 29P/Schwassmann-Wachmann, 13P/Olbers, 12P/Pons-Brooks.

A big thanks to our recent contributors: Salvador Aguirre, Anthony Amato, Michael Amato, Dan Bartlett, Dan Crowson, Jose Guilherme de Souza Aguiar, J. J. Gonzalez Suarez, Christian Harder, Carl Hergenrother, Eliot Herman, Rik Hill, Michael Jäger, John Maikner, Gianluca Masi, Efrain Morales Rivera, Mike Olason, Uwe Pilz, Gregg Ruppel, Chris Schur, Greg 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.

Halley-type comet 12P/Pons-Brooks arrives at perihelion this month after a 70-year journey since its last return in 1954. Though 4th magnitude this month, it will be a horizon-hugger in the evening sky. Northern hemisphere observers will be able to observe the comet until mid-month, while southern hemisphere observers will be able to pick it up at about the same time northerners lose sight of it.

Pons-Brooks isn’t the only Halley-type comet in the evening sky. Inbound 13P/Olbers is returning for the first time since 1956 and will brighten to 9th magnitude this month on its way to 7th magnitude in June and July.

Other comets in the sky this month are C/2021 S3 (PANSTARRS) at 9-10th magnitude in the morning sky, fading 144P/Kushida at 11-12th magnitude in the evening, and C/2023 A3 (Tsuchinshan-ATLAS) at 10th magnitude near opposition. Tsuchinshan-ATLAS is steadily brightening and may become a prominent naked-eye object in October.

Last month, the ALPO Comets Section received 160 images and 148 magnitude estimates of 24 comets: C/2024 E1 (Wierzchos), C/2023 H2 (Lemmon), C/2023 A3 (Tsuchinshan-ATLAS), C/2022 W3 (Leonard), 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), P/2014 VF40 (PANSTARRS), 479P/Elenin, 473P/NEAT, 207P/NEAT, 433P/(248370) 2005 QN173, 144P/Kushida, 62P/Tsuchinshan, 44P/Reinmuth, 32P/Comas Sola, 29P/Schwassmann-Wachmann, 13P/Olbers, 12P/Pons-Brooks, and 10P/Tempel.

A big thanks to our recent contributors: Salvador Aguirre, Anthony Amato, Michael Amato, Dan Bartlett, Michel Besson, Denis Buczynski, Dan Crowson, Michel Deconinck, Jose Guilherme de Souza Aguiar, Uwe Glahn, Juan Jose Gonzalez Suarez, Christian Harder, Carl Hergenrother, Eliot Herman, Rik Hill, Michael Jäger, Manos Kardasis, Patrick Lemaitre, John Maikner, Gianluca Masi, Erwin Matys, Frank J Melillo, Karoline Mrazek, Gary T. Nowak, Michael Olason, Ludovic Perbet, Allan Rahill, Michael Rosolina, Gregg Ruppel, Chris Schur, Greg T. Shanos, Tenho Tuomi, 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.