Comet 41P/Tuttle-Giacobini-Kresak
Color image of periodic comet 41P, obtained on 2017 Mar. 28 (22h45-23h10UT) with 60-cm, f/3.3 Deltagraph. Exposure time 6x30s in each filter. Copyright © 2017 by H. Mikuz, Crni Vrh Observatory.

Welcome to COBS!

Comet Observation database (COBS) was developed in 2010 and is maintained by Crni Vrh Observatory. It is a unique service offering comet observers to submit, display and analyse comet data in a single location and is opened to comet observers worldwide. Registered observers may submit the observations using a simple web-based form which will store their observations into an SQL database and display them in ICQ format.

Data stored in COBS database is freely available to everyone with respect to our data usage policy, and can be analysed with COBS online tools or exported and further used in other analysis software and publications.

Database currently contains more than 229000 comet observations of more than 1200 different comets and represents the largest available database of comet observations.

Amateur comet observers can make a useful contribution to science by observing comets and submitting their observations to the COBS, as the professional astronomers do not have the time nor the telescopes needed to gather such data. We encourage comet observers worldwide to submit their observations and contribute to the COBS database.

Light-curve of Comet 41P (Apr 23, 2017).

Recent observations

Type  Comet name  Obs date       Mag     Dia   DC  Tail     Observer
  V    41         2017 05 01.01   7.5    15    3            BUEaa
  V      2015V2   2017 05 01.01   8.6     8    4            BUEaa
  V      2015V2   2017 05 01.01   8.2    10    4            GUZ  
  V    41         2017 05 01.00   7.6   &15    2            GUZ  
  V      2015V2   2017 04 29.93   9.6     5.7  5            COLac
  V      2015V2   2017 04 29.85   8.4     6.5  4            MEY  
  V    71         2017 04 29.78  13.2     0.7  2            PEA  
  V      2017E1   2017 04 28.79  11.0     1.3  4            WYA  
  V      2015ER61 2017 04 28.77   7.8     8.2  6            WYA  
  V    71         2017 04 28.76  12.7     1.3  6            WYA  
  V     2         2017 04 28.76  12.3     1.4  3            WYA  
  V      2015ER61 2017 04 28.75   7.5     5    4            MAT08
  V    29         2017 04 28.74  13.6     0.5  5/           WYA  
  V    41         2017 04 28.73   8.1    10    4            WYA  
  V      2015V2   2017 04 28.72   8.8     3.8  6   17.3m304 WYA  


Comet Observing Planner

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Current comet magnitudes (April 21)

Comet                     Magnitude   Trend    Observable     When visible
PanSTARRS (2015 ER61)          7      bright   45 N to 80 S   morning
41P/Tuttle-Giacobinni-Kresak   7.5    fade     70 N to 15 S   all night
Johnson (2015 V2)              9      bright   70 N to 30 S   all night
Borisov (2017 E1)              9.5    steady   30 N to 60 S   early morning
Lovejoy (2017 E4)              9.5    fade     65 N to 35 S   morning
2P/Encke                      10      fade     10 N to 80 S   morning
PanSTARRS (2016 VZ18)         11      fade     70 N to 10 N   all night
65P/Gunn                      12      bright   30 N to 70 S   best morning
73P/Schwassmann-Wachmann      12      fade     20 S to 45 S   early morning
71P/Clark                     13      bright   45 N to 75 S   best morning
PanSTARRS (2016 R2)           13 ?    bright   Poor elongation
29P/Schwassmann-Wachmann      13 ?    varies   20 N to 70 S   morning
315P/LONEOS                   14      fade     70 N to 20 S   best evening

List of comets maintained by Jonathan Shanklin at

Latest news

Apr. 22, 2017

Close Approach Comets

Comets are some of the most interesting objects in the solar system. Water that filled the ancient oceans of Earth might have been delivered by comets. And there is growing evidence that many comets (as well as some primitive asteroids) contain molecules key to life. NASA has sent space probes to travel hundreds of millions of miles to study these icy interlopers from the outer solar system.


Mar. 27, 2017

Comet 67P full of surprises: Growing fractures, collapsing cliffs and rolling boulders

Images returned from the European Space Agency's Rosetta mission indicate the surface of comet 67P/Churyumov-Gerasimenko was a very active place during its most recent trip through the solar system, says a new study.


Mar. 09, 2017

New CCD photometry software keys added

COBS now includes the option to select Astrometrica version 4.10 and comphot photometry software when submitting CCD observations.


Feb. 12, 2017

Bright outburst of Comet 73P fragment

Thierry Noel has reported that Comet 73P/Schwassmann-Wachmann is showing a second component in images taken remotely from Chile (Observers: A. Maury, B. Sandness, T. Noel). Follow-up images taken by Andre Debackere using the Las Cumbres Observatory 1.0-m telescope at Siding Spring, Australia and measured by Richard Miles show that the main comet is accompanied by a much brighter secondary component surrounded by a faint coma.


Feb. 10, 2017

Massive comet-like object pollutes atmosphere of a white dwarf

For the first time, scientists using NASA's Hubble Space Telescope have witnessed a massive object with the makeup of a comet being ripped apart and scattered in the atmosphere of a white dwarf, the burned-out remains of a compact star. The object has a chemical composition similar to Halley's Comet, but it is 100,000 times more massive and has a much higher amount of water. It is also rich in the elements essential for life, including nitrogen, carbon, oxygen, and sulfur.