The ICQ Comet Information Website
Primary and secondary information on comets and observing comets:
This is a key place to begin looking for
useful and accurate information regarding news, observations, orbital
data, designations and names, and good links regarding comets and related
topics [sponsored by the International Comet Quarterly (ICQ)].
(Quick aids: Site
map 1/Site map 2)
Special dated news items:
- The
Edgar Wilson Award
for comet discoveries in 2007-2008 has been
announced (see IAUC 8962),
with two recipients, for one comet.
[Earlier Wilson Award
recipients.] [9/19/08]
- The fourth International Workshop on Cometary Astronomy
(IWCA IV) was scheduled to be
held in the Osaka/Kobe area of Japan on the weekend of 2009 July 25-26,
after the July 22 total solar eclipse that will be visible from Asia,
but due to lack of international interest in travelling there, it has
been cancelled. The location of IWCA IV has now been changed to
Shanghai, China, on Thursday, 2009 July 23 (where the path of totality
will pass the previous day).
We are now looking to hold the
fifth
IWCA in Rio de Janeiro, Brazil,
on Saturday, August 8, at the city planetarium in conjunction with the
General Assembly of the International Astronomical Union. More news
here as it becomes available. [10/23/08]
- The only ground-based-observable comets currently known to be
brighter than total visual magnitude 12 are
C/2006
OF2 (near total visual mag 10.5-11),
C/2006
W3 (near total visual mag 10-11),
C/2007
N3 (near total visual mag 8-9),
C/2008
A1 (near total visual mag 7),
C/2008
J1 (near total visual mag 12),
6P
(near total visual mag 9),
and 19P
(near total visual mag 11);
and 29P
(near total visual mag 10-11).
[10/27/08]
- Comets in urgent
need of
photometric observation [new webpage added 10/10/05]
- We are gradually making various articles and data of past published issues
of the ICQ
available here on the
ICQ website.
- The October 2008 quarterly issue of the ICQ is in preparation.
The delayed 2008 Comet Handbook is
nearing completion and should be printed by the end of 2008 with ephemerides
for 2008 and the first half of 2009; the 2009 Comet Handbook will then
be published in the first half of 2009, and the 2010 version before the end
of 2009 to get back on our old schedule.
The 14-page July 2008 quarterly issue of the ICQ was mailed out to
paying subscribers on 2008 Oct. 27. The 60-page April 2008 quarterly issue
of the ICQ was mailed on 2008 Oct. 3.
[Other recent ICQ
mailing dates.]
- Special ICQ
observing project.
- Comet 17P/Holmes underwent a huge outburst of some 13-14 magnitudes
(the largest ever known for a comet in only a day or two)
around 2007 Oct. 24, attaining total visual mag 2.4 +/- 0.2 in the
last week of October. It is only slowly declining in brightness as
it moves slowly through the constellation Perseus, well placed for
northern-hemisphere observers into early 2008.
Additional
information is available here.
[11/10/07]
- In 2007 April, the CfA changed the first part of its URL from
cfa-www to cfa.www. In addition, on 2007 April 19, the Computation
Facility at the CfA deleted the unix subdirectory /ps, where all of
the ICQ/CBAT/MPC/NELPAG webpages were at one time located (and many
were still located at the time of the deletion). The files were
all moved to new subdirectories, and in the case of the ICQ webpages,
a /icq subdirectory was created so that there is now an /icq part to
most or all ICQ webpages. This creates great problems, because it
will take many hours (probably spread over many months, realistically,
given our other work-load issues) to fix all the broken links in
the ICQ webpages (and unfortunately, this goes for the other webpages
in our group, as well). If you get such a broken link, try to
manually delete out the /ps part of the URL in your web-browser
URL-address window and type in /icq instead (for ICQ pages, or
/iau for CBAT webpages).
Need help?
Try our search program.
- After being visible in broad daylight for several days in the second week of
January 2007, comet
C/2006 P1
(McNaught) passed its perihelion and was visible to southern-hemisphere
observers (only) in the third and fourth weeks of January as a spectacular
evening object after sunset, low in the west. Brightness estimates
by many observers
show this to be
the brightest comet
observed in over forty years; see also the
nice
spacecraft images and
beautiful
southern-hemisphere photographs.
Among the very best photos of C/2006 P1 are those by
Rob McNaught and
Gordon Garradd.
- ALERT! We have introduced additional screening software to
block spam e-mail, due to its prolific increase; it is strongly recommended
that those sending e-mail to the ICQ or the CBAT remove ALL html-encoded
text, as we cannot read such text easily (we do not use web browsers for
reading e-mail) and such text may be deleted by our anti-spam software. (This
means: send plain ASCII text *only*, *not* plain ASCII text plus html-encoded
text in same message. The vast majority of ICQ contributors have no problem
sending ASCII-only e-mail with contributed observations, so HTML-encoding is
a natural place to attack SPAM e-mail since the vast majority of SPAM has
html-encoding.)
[11/14/03]. Due to excessive spam-e-mailing, our Computation Facility
took drastic measures on 1998 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 (chiefly, if your e-mail address
has a .com extension), your e-mail may not reach us
(and therefore
please read this)
[8/17/98].
- There was a computer crash on 2004 June 24 involving the main ICQ
disk. While copies of most data are available on other computers,
there was a loss of some unpublished (pending) ICQ-formatted data
and of some unposted (pending) IAUC/comet-magnitudes-webpage-format
data.
- What is The International Comet
Quarterly?
- Currently-observable comets:
ephemerides,
elements, and links to magnitude estimates
- Recent comet magnitude estimates
- The
most recent observation of each recently observed comet, as
reported to the Minor Planet Center (astrometric data, about half of
which have magnitudes). Important note: this is compiled from our
astrometric archives; listed observations do not mean that they are real -- sometimes
bad observations get past the software checks -- and the magnitudes are often off by
several magnitudes. Further, the last observation does not mean that the specific comet
either does or does not need observation urgently. At any rate, it is suggested that --
for most comets -- observations be made of each comet by each observer once
or twice a week, 3-4 observations per night, if possible; more frequent observation
by a single observer usually is not warranted or even encouraged -- being better to
observe more objects in need of observation. And quality is always better than quantity!
- The
ICQ Comet Handbook, a special annual publication giving
orbital elements, ephemerides, predicted brightnesses, and (starting
with the 2007 edition) observability/elongation diagrams for comets.
- The 1997 edition of the ICQ Guide to Observing Comets is now
out of print, but we hope to have a revised edition
available soon. We have had a great
many requests for this popular item.
Additional information on comets (and related phenomena):
About This Service
Here are credits and a
user-feedback form.
These pages are 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 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
CfA
CBAT
MPC
