Comet C/2017 O1 (ASASSN1)
Color image of comet C/2017 O1 (ASASSN1), obtained on 2017 Jun 22 from Australia SSO, Itelescope.net. Exposure time 9x60 seconds.
Copyright © 2017 by Rolando Ligustri

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 230000 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 C/2017 O1 (ASASSN1) (Aug 21, 2017).

Recent observations

Type  Comet name  Obs date       Mag     Dia   DC  Tail     Observer
  V    71         2017 08 23.04  11.1     2    3/           GOI  
  V      2017O1   2017 08 22.21   9.9     4    4            GOI  
  C      2015ER61 2017 08 22.18  12.1     0.57 6            PAUaa
  V      2015VL62 2017 08 22.14  12.9     2    3            GOI  
  V      2015V2   2017 08 22.04   9.7     4    3            GOI  
  V   217         2017 08 19.74  12.8     1    3            WYA  
  V      2017O1   2017 08 19.72   9.5     6    4            WYA  
  V      2015ER61 2017 08 19.72  12.5     1.5  2            WYA  
  V    29         2017 08 19.46  13.9     0.8  2            WYA  
  V      2015VL62 2017 08 19.46  13.7     1    3            WYA  
  V    71         2017 08 19.44  11.8     2.1  3            WYA  
  V      2015V2   2017 08 19.42  10.5     3.5  5            WYA  
  V      2017O1   2017 08 19.10  10.4     4.5  3            COLac
  V      2017O1   2017 08 19.05   9.5     5    2            HAR11
  V      2015ER61 2017 08 17.69  12.1     1.2  2            WYA  

                            

Comet Observing Planner

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

Current comet magnitudes (August 8)

Comet                     Magnitude   Trend    Observable     When visible
Johnson (2015 V2)              9      fade     35 N to 90 S   evening
PanSTARRS (2015 ER61)         10      fade     55 N to 50 S   morning
ASASSN1 (2017 O1)             10      bright   50 N to 75 S   early morning
71P/Clark                     11      fade     35 N to 90 S   best evening
PanSTARRS (2016 R2)           11 ?    bright   30 N to 70 S   morning
217P/LINEAR                   12.5    fade     25 N to 25 S   early morning
29P/Schwassmann-Wachmann      13 ?    varies   50 N to 80 S   best morning
Lemmon-Yeung-PanS (2015 VL62) 13 ?    steady   55 N to 45 S   best morning
65P/Gunn                      14      fade     25 N to 70 S   evening
PanSTARRS (2015 O1)           14      steady   55 N to 25 S   best evening

List of comets maintained by Jonathan Shanklin at http://www.ast.cam.ac.uk/~jds.


Latest news

Jul. 26, 2017

Large, distant comets more common than previously thought

There are about seven times more long-period comets measuring at least 1 kilometer across than previously predicted, suggests new research. The researchers also found that long-period comets are, on average, nearly twice as large as 'Jupiter family' comets, whose orbits are shaped by Jupiter's gravity and have periods of less than 20 years.

more...

Jul. 07, 2017

Bizarro comet challenging researchers

Scientists pursue research through observation, experimentation and modeling. They strive for all of these pieces to fit together, but sometimes finding the unexpected is even more exciting. That's what happened recently to a researcher who studies comets, asteroids and planetary formation and was part of a team that published a study focused on the comet 174P/Echeclus. It didn't behave the way the team was expecting.

more...

Jun. 27, 2017

New tool for CCD photometry - tutorial

CCD photometry of comet still remains as a very difficult work, especially for most wanted total coma magnitudes, compatible with visual observations. Also the usual problem is creating of proper ICQ coded line of observation. To help observers with this, I programmed an application - tool for comet observers, which is now in testing - beta phase.

more...

Jun. 06, 2017

New Comet: C/2017 K4 (ATLAS)

CBET nr. 4397, issued on 2017, June 01, announces the discovery of a comet (magnitude ~17) by the "Asteroid Terrestrial-impact Last Alert System" (ATLAS) Team on CCD exposures taken on May 26.5 with the ATLAS 0.5-m f/2.0 Schmidt telescope at Haleakala. The new comet has been designated C/2017 K4 (ATLAS).

more...

May. 12, 2017

COBS maintenance downtime 17.05.2017!

Due to a COBS servers system upgrade, we will have some website downtime on Wednesday 17.05.2017.

more...