The ICQ Comet Information Website

Primary and secondary information on comets and observing comets:

• ALERT! Due to excessive spam-e-mailing, our Computation Facility took drastic measures on August 14 to block e-mail from many e-mail extensions. Contributors of cometary observations to the ICQ, the CBAT, and the MPC need to be aware of this: if you do not have a .edu, .gov, or .org extension, your e-mail may not reach us (and therefore please read this). [8/17/98]
• There is a special, dated experiment being undertaken now that experienced visual comet observers are urged to take part in, in order to get an understanding of the spectral response of the human eye for astronomical photometry. The survey is being conducted by the AAVSO, and the results are due by 1998 September 22. [The AAVSO web site has been down Sept. 17-18; interested individuals can get hardcopy copies of the charts and instructions by postal mail from AAVSO, 25 Birch St., Cambridge, MA 02138-1205, U.S.A.; it may be possible to get the material via ftp on the Internet or via fax, and you can contact the AAVSO via e-mail at AAVSO@AAVSO.ORG] [8/18/98]
• The Edgar Wilson Award for comet discoveries has been announced. [6/11/98]
• Comet 52P/Harrington-Abell is currently in major outburst near total visual mag 11-12 (some 10 magnitudes brighter than predicted; note that only a handful of rough photographic magnitudes are on the record from large telescopes during 1955-1975, but it definitely appears to be many magnitudes brighter than normal). There are unconfirmed reports that the comet has split. [8/19/98]
• The brightest comets right now are 21P/Giacobini-Zinner (total visual mag 8.5-9.5), 88P/Howell (mag 10-10.5), C/1995 O1 (Hale-Bopp) (mag 10-10.5), and C/1998 P1 (Williams) (near mag 9, close to the sun) [10/26/98]
• Recent comet discoveries include P/1998 QP₅₄, P/1998 S1, C/1998 T1, C/1998 U1, P/1998 U2, and 1998 U3.
• Recent comet recoveries include 137P/1998 K6 = P/1990 UL₃ (Shoemaker-Levy 2), and 138P/1998 O1 = P/1991 V2 (Shoemaker-Levy 7).

• What is The International Comet Quarterly?
• Currently-observable comets: ephemerides, elements, and links to magnitude estimates
  • Recent comet magnitude estimates
  • Helpful information on observing for contributors
  • Recommendations for reference-magnitude sources (to use for comet-magnitude estimates)
  • The annual ICQ Comet Handbook, a special publication (1998 edition now available)
• Definition of comet "magnitude"
  • Glossary of comet and astronomical terms
• Limited copies of the ICQ Guide to Observing Comets may still be available.
• The second International Workshop on Cometary Astronomy (IWCA II) will be held immediately after the European total solar eclipse of 1999 August 11. Further information is available here.

Additional information on comets (and related phenomena):

• Ephemerides of Bright Comets
• Ephemerides/elements for all currently-observable comets
• Lists and Plots regarding Comets
• Correspondence of Old- and New-Style Designations
• Periodic Comet Numbers (new-style), in Alphabetical Order or in Numerical Order
• How to Report a Comet Discovery
• Astronomical headlines from recent Circulars of the CBAT and MPC.
• Index to the CBAT/MPC/ICQ pages
• Is Pluto a giant comet?
• CBAT/ICQ press information sheet on C/1995 O1 (Hale-Bopp)
• Tip: Whenever one comes across a reference to comet C/1995 O1 (Hale-Bopp) as "the Hale-Bopp comet", one can be pretty sure that the information attached to that phrase is compiled by somebody unfamiliar with comets and thus prone to error and misinformation. (People familiar with comets will either use their proper designations or refer to them as "comet Hale-Bopp", "Halley's Comet", or simply "Hale-Bopp", but never "the Halley comet" or "the Hale-Bopp comet"). [This might be analagous to one saying "game ballfoot" iustead of "football game", or "office post" instead of "post office", or "Church Catholic Roman" instead of "Roman Catholic Church" --- not strictly incorrect, perhaps, but obviously odd to those familiar with those subjects.]

• Recommended links to other Websites that contain useful and original comet (and some meteor) material/information
• Recommended publications to general information on comets

• Information on reporting atmospheric fireballs (bright meteors)
• Information on the scourge of light pollution, and what you can do to help make the sky a better place to view comets in! Some pages were produced and made available here because of the prominence of this problem to cometary observers.

About This Service

These pages were designed for the VMS port of version 2.4 of Mosaic. These pages are also light on inline images -- we are considerate of users who may be accessing these pages over slow (modem) connections! They are also intended to be Lynx (and other text-browser) friendly. We are committed to keeping our pages accessible to as many browsers as possible (a courtesy that we'd like to see many other webmasters imitate!).

Further information is available via e-mail from icq@cfa.harvard.edu

Index to the CBAT/MPC/ICQ pages.

New England Light Pollution Advisory Group (NELPAG)

SAO CBAT MPC