Latest image

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 261000 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/2019 L3 (ATLAS) (Sep 25, 2021).

Type Comet name Obs date Mag App T Pow Dia DC Tail PA Obs
V P/2021 Q5 2021 09 19.80 13.5 40.0 L 144 1.2 1 YOS04
V C/2019 L3 2021 09 19.78 11.0 40.0 L 75 1.6 7 YOS04
V 15P 2021 09 19.77 13.3 40.0 L 144 0.9 2 YOS04
V 4P 2021 09 19.76 11.8 40.0 L 75 1.8 4/ YOS04
V 67P 2021 09 19.75 11.3 40.0 L 75 1.1 7/ YOS04
V C/2020 T2 2021 09 19.41 10.4 40.0 L 144 1.4 3/ YOS04
C 15P 2021 09 19.19 14.5 31.5 C A200 1.9 CARah
C 4P 2021 09 19.17 11.5 31.5 C A200 3.9 CARah
C 29P 2021 09 19.15 13.8 31.5 C A200 1.5 CARah
C 67P 2021 09 19.13 11.1 31.5 C A200 4.5 CARah
C P/2021 N2 2021 09 19.10 17.0 31.5 C A500 0.4 CARah
C C/2020 K1 2021 09 18.91 16.9 31.5 C a900 0.4 CARah
C C/2017 K2 2021 09 18.89 13.2 31.5 C A200 0.9 CARah
C C/2020 R2 2021 09 18.87 18.0 20.0 C a120 PAP04
C C/2019 U5 2021 09 18.87 16.5 31.5 C A020 0.4 CARah
C 6P 2021 09 18.74 12.5 20.0 C a120 3 PAP04
C 8P 2021 09 18.39 9.0 13.5 A a600 4 5 MAT08
C 4P 2021 09 18.16 10.8 30.0 L B400 4 13.4m 271 DEK01
C 108P 2021 09 18.03 14.0 20.0 C a120 1 PAP04
C 19P 2021 09 17.75 14.5 20.0 C a120 1.5 PAP04


Comet Observing Planner

Start session:
End session:
Limiting mag:
Min altitude:
Min Solar Elongation:
Min Lunar Elongation:

Current comet magnitudes and observable region

Comet name Mag Trend Observable Visiblity
342P/SOHO 8.0 bright 60N to 90S Early evening Evening
8P/Tuttle 10.0 fade 73N to 90S Early evening Early evening
67P/Churyumov-Gerasimenko 11.0 bright 90N to 70S Best morning Best morning
4P/Faye 11.0 bright 90N to 73S Best morning Early evening
C/2020 T2 (Palomar) 11.0 fade 67N to 90S Evening Evening
C/2019 L3 (ATLAS) 11.0 bright 90N to 46S Best morning Early evening
19P/Borrelly 12.5 bright 31N to 90S Never up Never up
C/2021 O1 (Nishimura) 12.5 fade 90N to 83S Poor elongation Poor elongation
C/2017 K2 (PANSTARRS) 12.5 steady 90N to 62S Best evening Evening
C/2020 X3 (SOHO) 12.5 fade 68N to 90S Evening Best evening
6P/dArrest 13.0 fade 65N to 90S Evening Best evening
73P-V/Schwassmann-Wachmann 13.0 bright 83N to 90S Early evening Early evening
97P/Metcalf-Brewington 13.5 bright 90N to 86S Best morning Best morning
P/2013 PA104 (PANSTARRS) 13.5 fade 84N to 90S Best evening Best evening
205P-B/Giacobini 14.0 fade 85N to 90S Best evening Best evening
15P/Finlay 14.0 fade 90N to 63S Best morning Early evening
C/2021 A1 (Leonard) 14.0 bright 90N to 52S Evening Early evening
C/2019 T4 (ATLAS) 14.0 steady 66N to 90S Early evening Early evening
29P/Schwassmann-Wachmann 14.0 steady 90N to 58S 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

Aug. 31, 2021

New Comet C/2021 P4 (ATLAS)

With the MPEC 2021-Q42 issued on 21 August 2021, the discovery of a new Magn comet is announced. 19.4 identified by the ATLAS-HKO program (T05).


Aug. 24, 2021

Interstellar comets like Borisov may not be all that rare

Astronomers calculate that the Oort Cloud may be home to more visiting objects than objects that belong to our solar system.


Aug. 05, 2021

New Comet C/2021 O3 (PANSTARRS)

CBET xxxx & MPEC 2021-P05, issued on 2021, August 01, announce the discovery of a new comet (magnitude ~20) on CCD images taken on July 26.5 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala. The new comet has been designated C/2021 O3 (PANSTARRS).


Jul. 27, 2021

New Comet C/2021 N3 (PANSTARRS)

CBET 5003 & MPEC 2021-O39, issued on 2021, July 22, announce the discovery of a new comet (magnitude ~20.5) on CCD images taken on July 13.5 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala (numerous pre-discovery observations going back an additional month were later identified). The new comet has been designated C/2021 N3 (PANSTARRS).


Jul. 24, 2021

New Comet P/2021 N2 (Fuls)

CBET 5000 & MPEC 2021-N137, issued on 2021, July 15, announce the discovery of a new comet (magnitude ~18.3) on CCD images taken on July 09.4 UT with the Catalina Sky Survey's 0.68-m Schmidt reflector (pre-discovery Catalina observations from June 27 were identified later). The new comet has been designated P/2021 N2 (Fuls).