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 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 257800 comet observations of more than 1380 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 image

Unfiltered image of comet C/2020 V2 (ZTF), obtained on 2022 Apr. 20 (22h17-22h29UT) with 60-cm, f/3.3 Deltagraph telescope and CCD. Exposure time was 10 minutes (10x60 seconds). Image scale is 0.8 arc sec/pixel.
Copyright © 2021 by H. Mikuz, Črni Vrh Observatory.

Comets visible today at Crni Vrh Observatory

Comet Mag T Source Best time Const Obs Chart Comet PK Comet MPC Type

Location: Crni Vrh Observatory
Latitude: 45.94583; longitude: 14.07111; elevation: 726.0

Comet finding charts provided by Dominic Ford: https://in-the-sky.org/

Lightcurve of comet C/2017 K2 (PANSTARRS)

Recent observations

Type Comet Obs date Meth Mag T App P Dia DC Tail Tail unit PA User

Latest news

New Comet C/2022 F1 (ATLAS)
May 01, 2022

CBET 5112 & MPEC 2022-G82, issued on 2022, April 06, announce the discovery of a comet (magnitude ~18.5) on CCD images taken on Mar. 30.3 UT with a 0.5-m f/2 Wright-Schmidt reflector at Rio Hurtado, Chile, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. The new comet has been designated C/2022 F1 (ATLAS).

Hubble Confirms Largest Comet Nucleus Ever Seen
April 12, 2022

NASA's Hubble Space Telescope has determined the size of the largest icy comet nucleus ever seen by astronomers. The estimated diameter is approximately 80 miles across, making it larger than the state of Rhode Island. The nucleus is about 50 times larger than found at the heart of most known comets. Its mass is estimated to be a staggering 500 trillion tons, a hundred thousand times greater than the mass of a typical comet found much closer to the Sun.

New Comet C/2022 E3 (ZTF) may reach mag. +6 in Feb. 2023
March 22, 2022

CBET 5111 & MPEC 2022-F13, issued on 2022, March 21, announce the discovery of an apparently asteroidal object (magnitude ~17) discovered on CCD images taken on Mar. 2 UT with a  1.2-m f/2.4 Schmidt telescope at Palomar in the course of the  "Zwicky Transient Facility" (ZTF) survey (MPC code I41). Subsequently, it has been found to show cometary appearance by CCD astrometrists elsewhere. The new comet has been designated C/2022 E3 (ZTF).

New Comet C/2022 E2 (ATLAS)
March 16, 2022

CBET 5109 & MPEC 2022-E227, issued on 2022, March 15, announce the discovery of an apparently asteroidal object (magnitude ~19) discovered on CCD images taken on Mar. 7 UT with a 0.5-m f/2 Schmidt reflector at Rio Hurtado, Chile, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. Subsequently, it has been found to show cometary appearance by CCD astrometrists elsewhere after it was posted on the Minor Planet Center's PCCP webpage. The new comet has been designated C/2022 E2 (ATLAS).

Comet 67P’s abundant oxygen more of an illusion, new study suggests
March 15, 2022

When the European Space Agency's Rosetta spacecraft discovered abundant molecular oxygen bursting from comet 67P/Churyumov-Gerasimenko (67P) in 2015, it puzzled scientists. They had never seen a comet emit oxygen, let alone in such abundance. But most alarming were the deeper implications: that researchers had to account for so much oxygen, which meant reconsidering everything they thought they already knew about the chemistry of the early solar system and how it formed.