Latest image
Comet 21P/Giacobini-Zinner
True color image of periodic comet 21P/Giacobini-Zinner, obtained on 2018 Aug. 23 (2h04-2h38UT) with 15-cm, f/6 Maksutov-Cassegrain and Canon EOS 6D DSLR. Exposure time was 12x120s at ISO3200.
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 235000 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 21P/Giacobini-Zinner (Sep 22, 2018).
Type Comet name Obs date Mag App T Pow Dia DC Tail PA Observer V 21 2018 09 21.10 8.6 10.0B 25 5 5/ 0.7 289 CER01 V 21 2018 09 21.08 8.3 18.5L 73 4.5 4/ 14.0m283 KWI C 21 2018 09 21.06 7.7 1.0R a 60 9.5 4/ 26.0m274 NOV01 V 64 2018 09 20.98 [12.1 15.0L 115 NOV01 V 21 2018 09 20.83 8.0 8.0B 20 4 4 CAM03 V 21 2018 09 20.08 7.8 19.8L 37 6.5 4 21.0m281 HAR11 V 21 2018 09 20.08 8.1 18.5L 73 4.5 4 14.0m280 KWI V 21 2018 09 19.87 8.3 20.0L 90 4 5 PEA V 21 2018 09 19.82 7.8 8.0B 20 4 5 CAM03 V 46 2018 09 19.81 13.3 41.0L 200 0.8 3 PEA C 38 2018 09 19.42 11.5 10.6R a300 6.2 3.6m254 RAMaa C 21 2018 09 19.42 7.0 10.6R a180 20 > 80.0m280 RAMaa C 46 2018 09 19.41 11.9 10.6R a300 6.9 RAMaa V 21 2018 09 19.32 7.4 8.0R 19 5 5 SOU01 V 21 2018 09 19.26 7.3 7.0B 15 5 6 SOU01more...
Comet Observing Planner
Current comet magnitudes and observable region
Comet Mag Trend Observable When visible
45N 45S
21P/Giacobini-Zinner 8.0 bright 90N to 25S All night Never up
C/2016 M1 (PANSTARRS) 9.0 fade 33N to 90S Never up Never up
C/2017 T3 (ATLAS) 9.5 fade 61N to 90S Early evening Evening
C/2018 N1 (NEOWISE) 11.0 fade 75N to 90S Evening Best evening
C/2016 R2 (PANSTARRS) 12.0 fade 90N to 38S All night Never up
C/2016 N6 (PANSTARRS) 12.5 steady 90N to 66S Poor elongation Poor elongation
48P/Johnson 12.5 steady 66N to 90S Best morning Best morning
P/2013 R3-A (Catalina-PANSTARRS) 13.0 steady 72N to 90S Best morning Best morning
P/2013 R3-B (Catalina-PANSTARRS) 13.0 steady 72N to 90S Best morning Best morning
364P/PANSTARRS 13.5 fade 55N to 90S Early evening Best morning
38P/Stephan-Oterma 13.5 bright 90N to 85S Early evening Early evening
29P/Schwassmann-Wachmann 14.0 steady 90N to 88S Best morning Best morning
37P/Forbes 14.0 fade 90N to 84S Best morning Best morning
C/2017 M4 (ATLAS) 14.0 steady 90N to 62S Best evening Evening
66P/du Toit 14.0 fade 75N to 90S Best morning Best morning
P/2010 H2 (Vales) 14.0 fade 67N to 90S Evening Best evening
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
The Comet Observation Database - Observer tools and case study (EPSC2018-644, Berlin 2018)
This paper introduces the main functionality of the COBS database [1, 2] that is of interest to a comet observer, with application to C/2004 R2 (Machholz).
The Comet Observation Database - Structure and content (EPSC 2018-632, Berlin 2018)
The Comet Observation Database (COBS) [1, 2] is a unique web service that enables comet observers to submit, display and analyse comet data in a single location. The service currently represents one of the largest databases of comet observations (containing more than 235,000 observations) and is available to comet observers worldwide.
Green comet makes closest approach to earth
On Sept. 10th, Comet 21P/Giacobini-Zinner ("21P" for short) will make its closest approach to Earth in 72 years--only 58 million km from our planet. This small but active comet is easy to see in small telescopes and binoculars as it shines like a 7th magnitude star. Michael Jäger of Weißenkirchen, Austria, sends this photo of 21P passing through the stars of Auriga on Sept. 7th.
A Green Comet Approaches Earth
Comet 21P/Giacobini-Zinner is approaching Earth. On Sept. 10th, it will be 0.39 AU (58 million km) from our planet and almost bright enough to see with the naked eye. Already it is an easy target for backyard telescopes.
The cautionary tail of Comet Swift–Tuttle
Comet Swift–Tuttle, formally 109P/Swift–Tuttle, is an enormous, icy comet on a 133 year orbit around the Sun, and the reason for the spectacular annual Perseids meteor showers on Earth.