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 website or exported for further processing, analysis and publication. The database currently contains more than 293700 comet observations of more than 1700 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

Comet C/2025 A6 (Lemmon), obtained on 2025 October 2 (3h18-4h13UT) UT with 28-cm, f/2.2 telescope and ASI6200 MC camera. 20x120 seconds exposures. Image scale is 2.5 arc sec/pixel. Rok Palcic, Rezman Observatory (E-EYE Spain).

Comets visible today at Crni Vrh Observatory

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

Location: Crni Vrh Observatory
Latitude: 45.94583; longitude: 14.07111; elevation: 726.0
Limiting mag: 15; Min altitude: 0; Min solar elong: 0; Min moon elong: 0
All times are in UTC

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

Lightcurve of comet C/2025 A6 (Lemmon)

Recent observations

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

Latest news

Where do 3I/ATLAS and other interstellar visitors come from?
September 27, 2025

Roughly one trillion billion million objects reside in interstellar space — that’s a 1 followed by 27 zeros — but only three have ever been discovered passing through the Solar System. These are our sole known visitors from other stars.

Bright Comet suprise
September 12, 2025

A bright comet has emerged from behind the sun, surprising astronomers. Introducing, Comet SWAN25B

Interstellar Comet imaged during Lunar eclipse
September 09, 2025

On Sept 7th, darkness fell across the Kalahari Desert as Earth's shadow enveloped the full Moon. It was a total lunar eclipse--and the perfect time to photograph an interstellar comet. "We took advantage of the total lunar eclipse to take a deep image of Comet 3I/ATLAS under the dark skies of Namibia," says amateur astronomers Michael Jäger and Gerald Rhemann. Here is what they saw.

NASA’s Webb Space Telescope Reveals Secrets of Interstellar Comet 3I/ATLAS
September 02, 2025

Webb, Hubble, and SPHEREx are joining forces to study the interstellar comet 3I/ATLAS, revealing details about its structure and chemistry. The comet isn’t dangerous, but it’s offering scientists a rare chance to explore material from outside our solar system.

Our solar system has a new interstellar visitor: Meet 3I/ATLAS
August 30, 2025

Astronomers have spotted 3I/ATLAS, just the third interstellar object ever seen in our solar system. Bigger, faster, and possibly far older than ‘Oumuamua or Borisov, this icy traveler could help unlock clues about how other star systems formed billions of years ago.