Latest image

Comet C/2021 A1 (Leonard)
Image of comet C/2021 A1 (Leonard), obtained on 2021 December 28 (around 20h UT) from the ORM Observatory on La Palma, Canary Islands, with 200 mm, f/3.2 hypergraph and Canon 6D camera. Exposure time was 5 minutes at ISO 3200. Copyright © 2021 by Jure Skvarč.

Welcome to COBS!

Comet Observation database (COBS) saw first light in 2010 and is maintained by Crni Vrh Observatory. It is a free and unique service for comet observers worldwide which allows submission, display and analysis of comet data in a single location.

Amateur astronomers can make valuable contributions to comet science by observing comets and submitting their observations to COBS as professional astronomers typically do not have telescope time required to acquire regular observations. We therefore encourage comet observers worldwide to submit their observations and contribute to the COBS database.

Registered observers may submit observations using a web based form which which stores the observations in an SQL database and stores them in ICQ format. Observations may be queried and plotted in the web site or exported for further processing, analysis and publication. The database currently contains more than 264000 comet observations of more than 1400 different comets and represents the largest available database of comet observations.

The data stored in COBS is freely available to everyone who honors our data usage policy. Please cite COBS as the reference if you use it for comet studies.

Latest lightcurve

Light-curve of C/2021 A1 (Leonard) (Jan 28, 2022).

Type Comet name Obs date Mag App T Pow Dia DC Tail PA Obs
V C/2017 K2 2022 01 28.21 12.1 30.5 L 188 1 2/ KAR02
C 173P 2022 01 27.96 [17.5 20.3 Y B400 BUIaa
C 116P 2022 01 27.94 14.4 20.3 Y A980 & 0.3 & 2.5m 285 BUIaa
V 67P 2022 01 27.90 9.5 20.0 L 42 & 5 3 SCH04
C 67P 2022 01 27.90 9.8 20.3 Y C600 & 4 >21.0m 288 BUIaa
V C/2019 L3 2022 01 27.89 9.3 20.0 L 42 3 6 SCH04
C 4P 2022 01 27.87 12.6 20.3 Y a720 & 0.8 BUIaa
C 104P 2022 01 27.84 10.5 20.3 Y a720 & 4 BUIaa
C 19P 2022 01 27.83 9.7 20.3 Y A200 & 4 BUIaa
C C/2019 L3 2022 01 27.81 9.2 28.0 T A468 6 JAMaa
V C/2019 L3 2022 01 27.80 9.2 25.4 T 96 3.4 5 COLac
V 67P 2022 01 27.80 10.2 25.4 T 96 2.2 3/ COLac
V 104P 2022 01 27.79 10.0 25.4 T 96 2.6 3 COLac
V 19P 2022 01 27.78 9.1 25.4 T 96 2.9 4/ COLac
V 19P 2022 01 26.78 9.6 25.0 C 96 3 6 5.0m 25 DECaa
V C/2019 L3 2022 01 26.77 8.5 25.0 C 96 1 4 DECaa
V 104P 2022 01 26.76 9.7 25.0 C 62 6 2 DECaa
C 19P 2022 01 26.74 9.1 30.0 A a 30 3 PAP04
V C/2019 L3 2022 01 26.74 9.0 5.0 B 12 3 7 PAP04
C 67P 2022 01 26.73 9.6 30.0 A a 30 1 PAP04


Comet Observing Planner

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Current comet magnitudes and observable region

Comet name Mag Trend Observable Visiblity
19P/Borrelly 9.0 steady 90N to 88S Evening Evening
C/2021 A1 (Leonard) 9.0 fade 54N to 90S Early evening Evening
C/2019 L3 (ATLAS) 9.0 steady 90N to 63S Best morning Best evening
104P/Kowal 10.0 fade 90N to 87S Evening Evening
67P/Churyumov-Gerasimenko 10.0 fade 90N to 61S Best morning Best morning
29P/Schwassmann-Wachmann 11.5 steady 90N to 60S Best evening Evening
C/2017 K2 (PANSTARRS) 11.5 bright 90N to 78S Early evening Early evening
9P/Tempel 1 12.0 bright 70N to 90S Early evening Early evening
4P/Faye 12.5 fade 90N to 80S Best evening Best evening
83D/Russell 12.5 bright 66N to 90S Early evening Early evening
C/2019 T4 (ATLAS) 12.5 bright 60N to 90S Best morning Best morning
8P/Tuttle 13.5 fade 35N to 90S Never up Never up
116P/Wild 13.5 bright 90N to 72S Best morning Best morning
P/2013 PA104 (PANSTARRS) 13.5 fade 84N to 90S Best evening Best evening
97P/Metcalf-Brewington 13.5 fade 88N to 90S Evening Evening
181P/Shoemaker-Levy 13.5 fade 87N to 90S Evening Early evening
100P/Hartley 14.0 bright 90N to 55S Best morning Early evening

The observable region is an approximate indication of the latitude at which the comet may be seen. The period when visible is calculated for latitude 45°N and 45°S.

Latest news

Dec. 22, 2021

Comets’ heads can be green, but never their tails. After 90 years, we finally know why

A study has solved a 90-year-old mystery by proving the mechanism by which dicarbon -- the chemical that makes some comets' heads green -- is broken up by sunlight. This explains why the vibrant green color never reaches the comet's tail.


Dec. 18, 2021

What happened to C/2021 A1 (Leonard)?

Recently we have observed a rapid change in brightness of comet C/2021 A1 (Leonard). Magnitude of this comet should be strongly enhanced by forward scattering around 14. and 15. December 2021 and the days around this date. However observations indicating possible outburst near this date.


Nov. 10, 2021

New Comet P/2021 U3 (Attard-Maury)

CBET 5064 & MPEC 2021-V21, issued on 2021, November 02, announce the discovery of a new comet (magnitude ~19) by A. Maury and G. Attard on CCD images taken on October 24.3 UT with the 0.28-m f/2.2 Rowe-Ackermann Schmidt astrograph at San Pedro de Atacama, Chile in the course of the MAP (W94) survey. The new comet has been designated P/2021 U3 (Attard-Maury). This is the 4th amateur comet discovery of 2021. It is also the second comet discovered using the synthetic tracking technique (using TYCHO software).


Oct. 25, 2021

To watch a comet form, a spacecraft could tag along for a journey toward the sun

A new article proposes that space probes could hitch a ride with 'centaurs' as they become comets. Along the way, the spacecraft would gather data that would otherwise be impossible to record -- including how comets, Earth-like planets, and even the solar system formed.


Oct. 02, 2021

New Comet P/2021 Q5 (ATLAS)

CBET 5029 & MPEC 2021-R98 , issued on 2021, September 06, announce the discovery of a new comet (magnitude ~17) on CCD images taken on August 29.6 UT with a 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. The new comet has been designated P/2021 Q5 (ATLAS).