November is sort of a transition month. For northern observers, we lost C/2017 K2 (PANSTARRS) and C/2022 P1 (NEOWISE). Even down south, K2 is becoming a more difficult object to observe as it approaches conjunction. And we await next year’s bright comets, C/2020 V2 (ZTF) and C/2022 E3 (ZTF), which are just on the verge of being bright enough for most small aperture observers. 

November sees the return of two comets that dropped out of last month’s focus. 73P/Schwassmann-Wachmann was supposed to be faint at 14-15th magnitude but a recent outburst has it back at 10-11th magnitude. C/2019 L3 (ATLAS) has recently been re-observed and is still a 10th magnitude object. 

Rounding out the comets expected to be brighter than 12th magnitude this month are two short-period comets, 81P/Wild and 118P/Shoemaker-Levy. Both will be around 11th magnitude.

Last month the ALPO Comets Section received 76 magnitude estimates and 33 images/sketches of comets C/2022 R2 (ATLAS), C/2022 P1 (NEOWISE), P/2022 L3 (ATLAS), C/2022 E3 (ZTF), C/2021 Y1 (ATLAS), C/2021 X1 (Maury-Attard), C/2021 T4 (Lemmon), C/2021 QM45 (PANSTARRS), C/2021 E3 (ZTF), C/2020 Y2 (ATLAS), C/2020 V2 (ZTF), C/2020 S4 (PANSTARRS), C/2020 K1 (PANSTARRS), C/2019 O3 (Palomar), C/2019 L3 (ATLAS), C/2017 K2 (PANSTARRS), 404P/Bressi, 327P/Van Ness, 244P/Scotti, 150P/LONEOS, 117P/Helin-Roman-Alu, 81P/Wild, 73P/Schwassmann-Wachmann, 29P/Schwassmann-Wachmann, 22P/Kopff, 12P/Pons-Brooks, and 2P/Encke. A big thanks to our recent contributors: Dan Bartlett, Denis Buczynski, J. J. Gonzalez, Jose Guilherme de Souza Aguiar, Christian Harder, Carl Hergenrother, Eliot Herman, John Maikner, Martin Mobberley, Uwe Pilz, 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.

Much of this month’s comet action is shifting to the south. The brightest comet in the sky remains C/2017 K2 (PANSTARRS) at 8th magnitude though it is already lost to observers at northern mid-latitudes by early in the month. C/2022 P1 (NEOWISE) should peak around 9th magnitude early in the month. Though visible from both hemispheres it is a much easier site the further south one is. Looking ahead, C/2022 E3 (ZTF) is rapidly brightening from 11th to 10th magnitude and the prospects of it becoming a bright 5th magnitude object early next year still looks good. 

Last month the ALPO Comets Section received 81 magnitude estimates and 20 images/sketches of comets C/2022 P1 (NEOWISE), C/2022 E3 (ZTF), C/2020 V2 (ZTF), C/2020 K1 (PANSTARRS), C/2017 K2 (PANSTARRS), 422P/Christensen, 395P/Catalina-NEAT, 378P/McNaught, 327P/Van Ness, 286P/Christensen, 285P/LINEAR, 276P/Vorobjov, 259P/Garradd, 238P/Read, 196P/Tichy, 157P/Tritton, 127P/Holt-Olmstead, 117P/Helin-Roman-Alu, 95P/Chiron, 73P/Schwassmann-Wachmann, 61P/Shajn-Schaldach, 57P/du Toit-Neujmin-Delporte, 51P-D/Harrington, 44P/Reinmuth, 39P/Oterma, 29P/Schwassmann-Wachmann, 22P/Kopff, 12P/Pons-Brooks and 2P/Encke. A big thanks to our recent contributors: Dan Bartlett, J. J. Gonzalez, Jose Guilherme de Souza Aguiar, Christian Harder, Carl Hergenrother, Eliot Herman, Michael Jäger, John Maikner, Martin Mobberley, Uwe Pilz, 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.

C/2017 K2 (PANSTARRS) continues to dominate the attention of comet observers. It is currently the brightest comet in the sky at around magnitude 8, a position it should hold for a couple more months. Unfortunately for those at northern latitudes, September will probably be the last month to observe C/2017 K2 before it is lost in the glow of dusk. Southern observers will be able to follow the comet without interruption for many months to come.

Five other comets will be brighter than magnitude 12 though all may be fainter than magnitude 10.5 to 11.0. 73P/Schwassmann-Wachmann continues its habit of shedding secondary nuclei and so far, 5 new ones have been reported (though all are faint at 17-19th magnitude). C/2019 L3 (ATLAS) should return to view after its solar conjunction, first for southern observers, and later in the month for the northern hemisphere. C/2020 V2 (ZTF) and C/2022 E3 (ZTF) will brighten to around magnitude 11 by the end of September but will both get even brighter in 2023. Finally, C/2022 P1 (NEOWISE) is a brand-new discovery and due to its very rapid rate of brightening may be a 11th magnitude object this month.

Last month the ALPO Comets Section received 60 magnitude estimates and 38 images/sketches of comets C/2022 L1 (Catalina), C/2022 E3 (ZTF), C/2021 E3 (ZTF), C/2020 V2 (ZTF), C/2020 R7 (ATLAS), C/2020 K1 (PANSTARRS), C/2019 U5 PANSTARRS), C/2019 T4 (ATLAS), C/2017 K2 (PANSTARRS), 285P/LINEAR, 117P/Helin-Roman-Alu, 116P/Wild, 73P/Schwassmann-Wachmann, 29P/Schwassmann-Wachmann, and 22P/Kopff. A big thanks to our recent contributors: Dan Bartlett, Denis Buczynski, J. J. Gonzalez, Jose Guilherme de Souza Aguiar, Christian Harder, Carl Hergenrother, Eliot Herman, Michael Jäger, Gianluca Masi, Martin Mobberley, Uwe Pilz, Michael Rosolina, 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’s ALPO Comet News will be shorter than usual. Basically, I’ve been having trouble finding the time to support the production of these reports. To lighten the work load a bit, I am only highlighting comets brighter than magnitude 12.0 rather than 13.0. So, a few comets from the past few months which might be expected to be discussed in these pages have been dropped. The upside is this issue is actually going out on the 1st of the month (OK, the 2nd for posting on the ALPO site)!

C/2017 K2 (PANSTARRS) is near its peak brightness this month at around magnitude 8. Northern hemisphere observers only have another month or two to observe it before it travels too far south. Southern observers will be able to continue observing K2 for a long time to come. Among the fainter comets, 73P/Schwassmann-Wachmann has split once again. Michael Jäger has reported on the comet-ml list that at least two faint 19th magnitude secondaries have been imaged. With 73P reaching its peak brightness at ~11th magnitude at the end of August, perhaps a few more secondaries will be detected.

C/2022 E3 (ZTF) will be around 12th magnitude this month. The comet is continuing to brighten at a healthy rate increasing confidence that it will become a nice binocular or even borderline naked eye object early next year.

In June the ALPO Comets Section received 72 magnitude estimates and 36 images/sketches of comets C/2022 E3 (ZTF), C/2020 V2 (ZTF), C/2020 R7 (ATLAS), C/2020 K1 (PANSTARRS), C/2019 U5 (PANSTARRS), C/2019 T4 (ATLAS), C/2017 K2 (PANSTARRS), 426P/PANSTARRS, 377P/Scotti, 291P/NEAT, 117P/Helin-Roman-Alu, 73P/Schwassmann-Wachmann, 61P/Shajn-Schaldach, 22P/Kopff, 12P/Pons-Brooks, and 9P/Tempel. A big thanks to our recent contributors: Dan Bartlett, J. J. Gonzalez, Jose Guilherme de Souza Aguiar, Christian Harder, Carl Hergenrother, Eliot Herman, Michael Jäger, John Maikner, Martin Mobberley, Charles Morris, Uwe Pilz, Raymond Ramlow, Michael Rosolina, Gregg Ruppel, John D. Sabia, Chris Schur, Tenho Tuomi, and Chris Wyatt.

I’d like to especially thank Charles Morris and Jose Guilherme de Souza Aguiar who have agreed to contribute their observations to the ALPO. Both Charles and Jose were prolific past contributors and we welcome them back!

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.

Summary

The comet of the moment is C/2017 K2 (PANSTARRS). Currently around 8th magnitude, C/2017 K2 has become an interesting object for both visual and imaging observers. While K2 is visible from both hemispheres, the second brightest comet of the month, C/2021 E3 (ZTF) at 9-10th magnitude, is solely a southern hemisphere object. A number of fainter comets are in the 10th to 13th magnitude range, including 22P/Kopff, 73P/Schwassmann-Wachmann, 169P/NEAT, C/2019 L3 (ATLAS), C/2019 T4 (ATLAS), C/2020 V2 (ZTF), C/2021 P4 (PANSTARRS), and C/2022 E3 (ZTF). C/2022 E3 is still looking like it will become a nice borderline naked eye object in 2023.

In June the ALPO Comets Section received 52 magnitude estimates and 34 images/sketches of comets C/2022 L2 (ATLAS), C/2022 E3 (ZTF), C/2021 P4 (ATLAS), C/2021 F1 (Lemmon-PANSTARRS), C/2021 E3 (ZTF), C/2021 A1 (Leonard), C/2020 V2 (ZTF), C/2020 R7 (ATLAS), C/2020 K1 (PANSTARRS), C/2019 U5 (PANSTARRS), C/2019 T4 (ATLAS), C/2017 K2 (PANSTARRS), 337P/WISE, 327P/Van Ness, 325P/Yang-Gao, 287P/Christensen, 117P/Helin-Roman-Alu, 116P/Wild, 73P/Schwassmann-Wachmann, 45P/Honda-Mrkos-Pajdusakova, 22P/Kopff, and 12P/Pons-Brooks. A big thanks to our recent contributors: Dan Bartlett, John Chumack, J. J. Gonzalez, Christian Harder, Carl Hergenrother, Eliot Herman, Michael Jäger, John Maikner, Martin Mobberley, Michael Phillips, Uwe Pilz, Raymond Ramlow, Michael Rosolina, Gregg Ruppel, John D. Sabia, Chris Schur, Tenho Tuomi, and Chris Wyatt.

In addition to observations submitted directly to the ALPO, we occasionally use data from other sources to augment our analysis. We would like to acknowledge with thanks observations submitted directly to the ALPO as well as those originally submitted to the International Comet Quarterly, Minor Planet Center, and COBS Comet Observation Database. We would also like to thank the Jet Propulsion Laboratory for making available their Small-Body Browser and Orbit Visualizer and Seiichi Yoshida for his Comets for Windows programs that are used to produce the lightcurves and orbit diagrams in these pages. And last but not least, we’d like to thank Syuichi Nakano and the Minor Planet Center for their comet orbit elements, the asteroid surveys and dedicated comet hunters for their discoveries, and all of the observers who volunteer their time to adding to our knowledge of these amazing objects.

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.