Comet 45P/Honda-Mrkos-Pajdušakova
Color image of periodic comet 45P, obtained on 2017 Feb. 26 (2h23-2h30UT) with 60-cm, f/3.3 Deltagraph. Exposure time 60s 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 228000 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 45P (Mar 04, 2017).

Recent observations

Type  Comet name  Obs date       Mag     Dia   DC  Tail     Observer
  V    41         2017 03 26.00   7.2    24    5            COLac
  V      2015V2   2017 03 25.95  10.6     3.1  5            COLac
  V      2015V2   2017 03 25.92   9.6     5    4            MEY  
  V    41         2017 03 25.90   7.3    17    2/           MEY  
  V    41         2017 03 25.85   7.2    22    2/           CER01
  V     2         2017 03 25.79   8.0     2    7            MAT08
  V      2015ER61 2017 03 25.78   8.6     5    4            MAT08
  V      2017E4   2017 03 25.77   9.0     3.5  4            MAT08
  C      2017E4   2017 03 25.48   9.4   > 6.5               RAMaa
  C    41         2017 03 25.25   7.3   >35                 RAMaa
  V    41         2017 03 25.21   7.3    18    3            HER02
  V    41         2017 03 25.13 [ 7.3                       AGUaa
  V    41         2017 03 25.13   8.0    11    1            FRA01
  V      2015V2   2017 03 25.06   9.2     3.4  4   0.11     KUT  
  V    41         2017 03 24.97   7.5    20    2            KUT  


Comet Observing Planner

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Current comet magnitudes (March 21)

Comet                     Magnitude   Trend    Observable     When visible
2P/Encke                       6.5    fade      0 N to 70 S   early morning
41P/Tuttle-Giacobinni-Kresak   8.5    bright   80 N to 45 S   best evening
PanSTARRS (2015 ER61)          9      bright   50 N to 75 S   early morning
Lovejoy (2017 E4)              9      bright   45 N to 75 S   morning
Johnson (2015 V2)              9.5    bright   80 N to 30 S   best morning
45P/Honda-Mrkos-Pajdusakova   10      fade     80 N to 45 S   best morning
73P/Schwassmann-Wachmann      11      bright   10 N to 50 S   early morning
PanSTARRS (2016 VZ18)         11      steady   80 N to 15 S   evening
Borisov (2017 E1)             12      steady   35 N to 50 S   early morning
315P/LONEOS                   12.5    o'burst? 70 N to  5 S   all night
PanSTARRS (2016 R2)           13 ?    bright   15 N to 55 S   evening
29P/Schwassmann-Wachmann      13 ?    varies   Poor elongation
237P/LINEAR                   14      fade     In conjunction
Spacewatch (2011 KP36)        14      fade     Poor elongation

List of comets maintained by Jonathan Shanklin at

Latest news

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.


Jan. 30, 2017

Micro spacecraft investigates cometary water mystery

In September 2015, a team of astronomers successfully observed the entire hydrogen coma of the comet 67P/Churyumov-Gerasimenko, using the LAICA telescope onboard the PROCYON spacecraft. They also succeeded in obtaining the absolute rate of water discharge from the comet. Through our observations, we were able to test the coma models for the comet for the first time. This result is the first scientific achievement by a micro spacecraft for deep space exploration.


Jan. 12, 2017

New Comet: C/2017 A3 (Elenin)

CBET nr. 4344, issued on 2017, January 11, announces the discovery of a comet (magnitude ~18.2) by L. Elenin on three CCD images obtained with 0.4-m f/2.4 reflector + CCD at the ISON-SSO Observatory at Siding Spring on Jan. 5.4 UT. The new comet has been designated C/2017 A3 (Elenin).