Comets On The Doorstep - Where Once There Were Two, Now There Are THREE !
Friday, March 12 2004 @ 06:02 pm EST
Contributed by: bobmoody
Source - Oxford Astronomy Encyclopedia, 2002: Philip's (Division of Octopus Pub) p. 89-91
If all goes well, a pair of bright comets may grace our skies in late April through May, and one may linger into the early summer. Not since Comet Hyakutake in 1996 and Comet Hale-Bopp in 1997 have there been such bright comets well placed for viewing. These "small Solar System bodies" are known as C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR).
Now, add comet C/2004 F4 Bradfield to the mix. Bradfield has just recently been discovered by 76 year old Australian amateur astronomer William A. Bradfield in March, but wasn't officially named until April12th. Bradfiled adds this to his previous 17 comet discoveries since 1972.
Comet Bradfield was not visible to this observer the morning of April 25 at approximately 5:30-6:00 am. Estimates are that it was at magnitude 4.4 today, and that it will dim by 1/2 magnitude per every 2 days over the next week, making it nearly impossible to find without binoculars. See the Astronomy Picture of the Day for April 27 for a time-lapse image of Bradfield rising at: http://antwrp.gsfc.nasa.gov/apod/archivepix.html
Comet NEAT will pass within 0.32 AU of Earth on May 6, about 30 million miles away. It will not be visible to northern observers until mid-May and into June, but at it's closest point to the Sun (perihelion) on May 15, it may be as bright as 2nd magnitude at a distance of nearly 90 million miles from the Sun. By the end of May NEAT continues to move and change rapidly, passing near the Big Dipper at the end of May as a dimmer 5th magnitude object. This comet is a first-time visitor to the inner solar system.
C/2002 T7 (LINEAR) Discovered on October 14, 2002, the Lincoln Laboratory Near Earth Asteroid Research (LINEAR) survey first mis-identified this object as an asteroid. Further observations nearly two weeks later revealed it to be a comet beginning to outgas its volatile elements and form a coma at an estimated distance of just over 600 million miles. "T7" as it is better known, is the subject of intense study by AOAS member Mike Holloway from his home observatory about 12 miles NW of Van Buren, AR. T7 is just past its conjunction with the Sun, and was expected to brighten to an estimated 2nd magnitude around it's perihelion on April 23 at about 60 million miles from the Sun, and visible for a few days in the morning skies. T7 will be brightest for Earthly observers around May 19th when it will lie only 25 million miles from Earth and returns to the evening skies
See the links at the end of this story for images from Mike Holloway and other observers from around the world in their observations of these three bright comets. >
AOAS will host public outings to view the night sky the evenings of May 21st AND 22nd at Carol Ann Cross park on 74th Street, about 1 mile N. of Rogers at St Edwards Hospital. The observing is for the public, in association with Ft Smith City Parks, and is always FREE of charge. Make plans to bring your family and join members of AOAS for "the view of a lifetime"!
Arkansas Sky Observatory
Mike Holloway's page
Comet Q4 Observer Terry Lovejoy
Comet T7 - NASA/JPL
Comet Q4 - NASA/JPL
Sky & Telescope