Latest image

Comet 21P/Giacobini-Zinner
True color image of periodic comet 21P/Giacobini-Zinner, obtained on 2018 Sep. 20 (3h05-3h09UT) with 60-cm, f/3.3 Deltagraph telecope and LBVR filters. Exposure time was 30s in each filter.
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 236000 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/2018 V1 (Machholz-Fujikawa-Iwamoto) (Nov 21, 2018).

Type  Comet name  Obs date       Mag   App  T  Pow   Dia   DC  Tail PA  Observer
  V    64         2018 11 20.07 [10.6   20.0T   50                      AGUaa
  C      2018V1   2018 11 18.24   9.0    7.2R a120    2.82              JAMaa
  V      2018V1   2018 11 18.22   7.9   20.0L   42    5    6            SCH04
  V      2016N6   2018 11 18.20  12.5   30.5L  214    0.7  3            KAR02
  V      2018V1   2018 11 18.19   8.2   19.8L   49    3.5  4    4.5m300 HAR11
  V      2018V1   2018 11 18.17   8.3    5.0B   10    3.5  6            KAR02
  V    38         2018 11 18.17   9.9   25.2L   63    3    3            HAR11
  V      2018V1   2018 11 18.17   7.9   18.5L   73    4    4            KWI  
  V      2016R2   2018 11 18.15  13.4   25.2L  126    0.55 3            HAR11
  V    38         2018 11 18.10  10.1:  25.4T   96    2.9  4            COLac
  V    64         2018 11 18.08   9.0   19.8B   49    8    2            HAR11
  V    64         2018 11 18.08  10.3   25.4T   96    3.4  4            COLac
  V    38         2018 11 18.02   9.7   18.5L   73    2.9  3            KWI  
  V    38         2018 11 18.00   9.8   25.4L   64    3    3/           MEY  
  V    64         2018 11 18.00   9.3   18.5L   73    2.6  3            KWI  

Comet Observing Planner

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Limiting mag:
Min altitude:
Min Solar Elongation:
Min Lunar Elongation:

Current comet magnitudes and observable region

Comet                               Mag   Trend   Observable          When visible
                                                                  45N              45S
46P/Wirtanen                         6.0  bright  62N to 90S  Best morning     Best morning    
C/2018 V1 (Machholz-Fujikawa-Iwamoto)    7.0  bright  89N to 90S  Early evening    Early evening   
64P/Swift-Gehrels                    9.5  fade    90N to 54S  Best morning     Best evening    
C/2018 L2 (ATLAS)                   10.0  bright  90N to 83S  Evening          Early evening   
38P/Stephan-Oterma                  11.0  bright  90N to 65S  Best morning     Best morning    
C/2016 M1 (PANSTARRS)               11.0  fade    16N to 90S  Never up         Never up        
21P/Giacobini-Zinner                11.5  fade    53N to 90S  Early evening    Best morning    
C/2016 N6 (PANSTARRS)               12.5  steady  85N to 90S  Best morning     Best morning    
29P/Schwassmann-Wachmann            12.5  steady  89N to 90S  Best evening     Best evening    
C/2016 R2 (PANSTARRS)               12.5  steady  90N to 48S  Evening          Early evening   
78P/Gehrels                         13.0  bright  82N to 90S  Evening          Best evening    
C/2015 O1 (PANSTARRS)               14.0  steady  90N to 55S  Best morning     Early evening   
123P/West-Hartley                   14.0  bright  90N to 63S  Best morning     Early evening   
59P/Kearns-Kwee                     14.0  steady  90N to 65S  Best morning     Early evening   
C/2018 N2 (ASASSN)                  14.0  steady  47N to 90S  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

Nov. 16, 2018

NASA learns more about interstellar visitor 'Oumuamua

The first known interstellar object to visit our solar system -- named 'Oumuamua -- was detected in October 2017 by Hawaii's Pan-STARRS 1 telescope. But it was too faint for NASA's Spitzer Space Telescope to detect when it looked more than two months after the object's closest approach to Earth in early September. That 'non-detection' puts a new limit on how large the strange object can be, astronomers now report.


Nov. 12, 2018

New Comet C/2018 V1 (Machholz-Fujikawa-Iwamoto)

CBET 4569 (issued on 2018, November 08) and MPEC 2018-V151 (2018, November 11), announce the discovery of a 10th-magnitude comet by Donald E. Machholz (Colfax, CA, U.S.A) and independently by Shigehisa Fujikawa (Kan'onji, Kagawa, Japan) and Masayuki Iwamoto (Awa, Tokushima, Japan).


Nov. 04, 2018

Comet tails blowing in the solar wind

Combined observations of Comet McNaught -- one of the brightest comets visible from Earth in the past 50 years -- have revealed new insights on the nature of comets and their relationship with the Sun.


Oct. 26, 2018

Secret shared by comets and sand crabs

Researchers have found a mechanical connection between sand crab burrow widths and widths of cometary pits using a simple granular experiment.


Oct. 03, 2018

Comet landscape

On 30 September 2016, ESA’s Rosetta spacecraft came closer than ever to the target it had studied from afar for more than two years, concluding its mission with a controlled impact onto the surface of Comet 67P/Churyumov-Gerasimenko (67P/C-G).