Latest image

C/2019 L3 (ATLAS)
Unfiltered image of comet C/2019 L3 (ATLAS), obtained on 2021 Feb. 17 (19h31-19h43UT) with 60-cm, f/3.3 Deltagraph telescope and CCD. Exposure time was 10x60 seconds. Total exposure time 10 minutes.
Copyright © 2021 by H. Mikuz, Črni Vrh Observatory.

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 258000 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/2020 T2 (Palomar) (May 16, 2021).

Type Comet name Obs date Mag App T Pow Dia DC Tail PA Obs
C C/2021 A1 2021 05 15.95 17.1 50.0 L a600 0.4 HILaa
V C/2020 T2 2021 05 15.90 10.6 25.2 L 68 3 3 HAR11
C 99P 2021 05 15.89 17.6 31.5 C a840 0.4 CARah
V C/2020 R4 2021 05 15.03 11.7 54.0 L 120 2.1 3 KUT
V C/2020 T2 2021 05 14.99 10.7 25.0 L 60 2.8 5 KUT
C C/2017 K2 2021 05 14.95 14.2 20.0 L B400 2 LOSaa
V C/2020 R4 2021 05 14.93 10.4: 25.2 L 78 2.5 2 HAR11
C C/2020 T2 2021 05 14.91 11.2 20.0 L B400 9.2 LOSaa
V C/2020 T2 2021 05 14.88 10.1 7.0 B 16 3.5 6 PIL01
C C/2018 N2 2021 05 14.88 16.3 50.0 L a600 0.4 HILaa
V C/2020 R4 2021 05 14.87 10.0 7.0 B 16 4.5 PIL01
C C/2020 R4 2021 05 14.86 11.8 20.0 L B400 10.1 LOSaa
C C/2018 U1 2021 05 14.20 14.7 50.0 L a600 0.4 HILaa
C 246P 2021 05 14.19 13.3 50.0 L a600 0.8 HILaa
C C/2020 H6 2021 05 14.04 15.6 50.0 L a360 0.4 HILaa
C 117P 2021 05 14.02 15.5 50.0 L a600 0.4 HILaa
C C/2020 Y2 2021 05 14.01 15.8 50.0 L a600 0.4 HILaa
C C/2019 C1 2021 05 14.00 17.2 50.0 L a600 0.4 HILaa
C C/2021 C4 2021 05 13.99 16.9 50.0 L A080 0.4 HILaa
V C/2019 F1 2021 05 13.73 15.1 40.0 L 261 0.5 6 WYA


Comet Observing Planner

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Current comet magnitudes and observable region

Comet name Mag Trend Observable Visiblity
C/2020 T2 (Palomar) 11.0 bright 90N to 61S Best morning Best morning
C/2020 R4 (ATLAS) 11.0 fade 90N to 63S Best morning Best evening
C/2019 L3 (ATLAS) 12.0 bright 90N to 39S All night Never up
6P/dArrest 12.0 bright 90N to 74S Best morning Best morning
C/2020 F8 (SWAN) 12.0 steady 84N to 90S Early evening Evening
7P/Pons-Winnecke 12.5 bright 88N to 90S Best morning Best morning
C/2020 X3 (SOHO) 12.5 fade 68N to 90S Evening Best evening
C/2020 J1 (SONEAR) 13.5 steady 60N to 90S Best morning Best morning
P/2013 PA104 (PANSTARRS) 13.5 fade 84N to 90S Best evening Best evening
15P/Finlay 13.5 bright 78N to 90S Early evening Early evening
C/2017 K2 (PANSTARRS) 13.5 bright 90N to 47S Best morning Early evening
29P/Schwassmann-Wachmann 14.0 steady 90N to 63S Poor elongation Poor elongation
C/2021 D1 (SWAN) 14.0 fade 90N to 58S Evening Early evening
246P/NEAT 14.0 bright 63N to 90S Early evening Best morning
28P/Neujmin 14.0 fade 90N to 75S Early evening Early evening
C/2020 K5 (PANSTARRS) 14.0 bright 44N to 90S Never up Never up

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.

Top news

May. 09, 2021

New Reference catalog keys

New reference catalog keys were assigned for GAIA DR catalog and APASS catalog.


Latest news

May. 07, 2021

New Comet C/2021 E3 (ZTF)

CBET xxxx & MPEC 2021-J71 , issued on 2021, May 06, announce the discovery of an apparently asteroidal object (magnitude ~19.5) on CCD images taken on March 09.5 UT with the 1.2-m Schmidt telescope at Palomar in the course of the "Zwicky Transient Facility" (ZTF) search program. This object has been found to show cometary appearance by CCD astrometrists elsewhere. The new comet has been designated C/2021 E3 (ZTF).


Apr. 09, 2021

Exploring comet thermal history: Burnt-out comet covered with talcum powder

The world's first ground-based observations of the bare nucleus of a comet nearing the end of its active life revealed that the nucleus has a diameter of 800 meters and is covered with large grains of phyllosilicate; on Earth large grains of phyllosilicate are commonly available as talcum powder. This discovery provides clues to piece together the history of how this comet evolved into its current burnt-out state.


Apr. 09, 2021

New Comet C/2019 U5 (PANSTARRS)

CBET 4953 & MPEC 2021-G80, issued on 2021, April 07, announce that an apparently asteroidal object (magnitude ~21.0) discovered on CCD images obtained with the F51 Pan-STARRS 1 survey's 1.8m Ritchey-Chretien on 2019, October 22.22 and designated A/2019 U5 (cf. MPEC 2019-V10) has been found to show cometary appearance by other CCD observers over the past half year. The new comet has been designated C/2019 U5 (PANSTARRS).


Apr. 01, 2021

First interstellar comet may be the most pristine ever found

New observations indicate that the rogue comet 2I/Borisov, which is only the second and most recently detected interstellar visitor to our Solar System, is one of the most pristine ever observed. Astronomers suspect that the comet most likely never passed close to a star, making it an undisturbed relic of the cloud of gas and dust it formed from.


Mar. 27, 2021

New Comet C/2020 F7 (Lemmon)

CBET 4949 & MPEC 2021-F110, issued on 2021, March 25, announce that an apparently asteroidal object (magnitude ~21.0) discovered on CCD images obtained with the Mt. Lemmon Survey's 1.5-m reflector on 2020 Mar. 22 and designated A/2020 F7 (cf. MPEC 2020-G78) has been found to show cometary appearance by numerous other CCD observers over the past half year. The new comet has been designated C/2020 F7 (Lemmon).