Latest image

Comet C/2015 O1 (PANSTARRS)
False color unfiltered image of comet C/2015 O1 (PANSTARRS), obtained on 2018 Apr. 8 (1h13-1h23UT) with 60-cm, f/3.3 Deltagraph. Exposure time was 8x60s.
Copyright © 2018 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 234000 comet observations of more than 1200 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/2016 M1 (PANSTARRS) (Jul 18, 2018).

Type  Comet name  Obs date       Mag     Dia   DC  Tail     Observer
  C      2017S3   2018 07 18.43   7.5    10.1    > 91.0m299 RAMaa
  V      2017T3   2018 07 18.37   8.7     4    4/           GOI  
  V      2018N1   2018 07 18.19  11.1     3    2            GOI  
  C    21         2018 07 18.18   9.4     9.2       8.8m232 RAMaa
  V    21         2018 07 17.99   9.9     3   D5            MEY  
  V      2017S3   2018 07 17.95   7.4     5.5 D5            MEY  
  V      2017S3   2018 07 17.95   7.0     5    6            VAN16
  C      2017S3   2018 07 17.94   8.2     6                 JAMaa
  V      2017S3   2018 07 17.87   7.8     3    6/           TSV01
  V    21         2018 07 17.82  10.0     1.5  6            CAM03
  V    66         2018 07 17.81  12.4     2    1            CAM03
  V    37         2018 07 17.80  13.6     1    3            CAM03
  V    48         2018 07 17.79  13.1     1.5  5            CAM03
  V      2018N1   2018 07 17.78  10.0     7    2            CAM03
  V      2017M4   2018 07 17.52  14.0     0.5  5            CAM03

Comet Observing Planner

Start session:
Session length:
Limiting mag:
Min altitude:
Min Solar Elongation:
Min Lunar Elongation:

Current comet magnitudes and observable region

Comet                       Mag   Trend   Observable        When visible
                                                         45N            45S
C/2017 T3 (ATLAS)            8.5  bright  81N to 90S  Early evening  Early evening 
C/2016 M1 (PANSTARRS)        8.5  fade    36N to 90S  Never up       Never up      
C/2017 S3 (PANSTARRS)        8.5  bright  90N to 34S  All night      Never up      
21P/Giacobini-Zinner         9.5  bright  90N to 30S  All night      Never up      
C/2018 N1 (NEOWISE)         10.0  bright  66N to 90S  Best morning   Best morning  
C/2016 R2 (PANSTARRS)       12.0  fade    90N to 37S  All night      Never up      
364P/PANSTARRS              12.0  fade    63N to 90S  Early evening  Early evening 
C/2016 N6 (PANSTARRS)       12.5  steady  90N to 59S  Poor elongation Poor elongation
37P/Forbes                  13.0  steady  90N to 88S  Best morning   Best morning  
66P/du Toit                 13.0  fade    72N to 90S  Early evening  Best morning  
48P/Johnson                 13.0  bright  71N to 90S  Best morning   Best morning  
P/2013 R3-A (Catalina-PANSTARRS)   13.5  bright  73N to 90S  Best morning   Best morning  
P/2013 R3-B (Catalina-PANSTARRS)   13.5  bright  73N to 90S  Best morning   Best morning  
P/2010 H2 (Vales)           13.5  fade    69N to 90S  Best evening   Best evening  
C/2015 O1 (PANSTARRS)       14.0  fade    90N to 46S  Best evening   Early evening 
C/2017 M4 (ATLAS)           14.0  steady  90N to 52S  Best morning   Best morning  

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

Jul. 18, 2018

New Comet: C/2018 N2 (ASASSN)

MPEC 2018-O01, issued on 2018, July 16, announces the discovery of a comet (magnitude ~16.1) in the course of the "All-Sky Automated Survey for Supernovae" (ASASSN) program, in images taken 2018 July 7-11 with the 14-cm "Cassius" survey telescope at Cerro Tololo. The new comet has been designated C/2018 N2 (ASASSN).


Jul. 09, 2018

Molecular oxygen in comet's atmosphere not created on its surface

Scientists have found that molecular oxygen around comet 67P is not produced on its surface, as some suggested, but may be from its body.


Jun. 29, 2018

Chasing 'Oumuamua

The interstellar object 'Oumuamua perplexed scientists in October 2017 as it whipped past Earth at an unusually high speed. This mysterious visitor is the first object ever seen in our solar system that is known to have originated elsewhere.


Jun. 29, 2018

Our Solar System's First Known Interstellar Object Gets Unexpected Speed Boost

Using observations from NASA's Hubble Space Telescope and ground-based observatories, an international team of scientists has confirmed 'Oumuamua (oh-MOO-ah-MOO-ah), the first known interstellar object to travel through our solar system, got an unexpected boost in speed and shift in trajectory as it passed through the inner solar system last year.


Jun. 29, 2018

`Oumuamua gets a boost

`Oumuamua, the first interstellar object discovered in the Solar System, is moving away from the Sun faster than expected. This anomalous behavior was detected by a worldwide astronomical collaboration. The new results suggest that `Oumuamua is most likely an interstellar comet and not an asteroid.