On the morning of July 23, two amateurs discovered a new comet just south of the Sagittarius Teapot near the globular cluster M70. Alan Hale in Cloudcroft, NM, and Thomas Bopp near Stanfield, AZ, were both using 16-inch reflectors. They described the comet as a tailless, 11th-magnitude glow. Thanks to hundreds of positional observations, calculations by the IAU's Central Bureau for Astronomical Telegrams now show Comet Hale-Bopp to be a whopping 7 astronomical units from the Sun -- well beyond Jupiter, and farther away than any comet discovered by amateurs before. The fact that it can be seen at all suggests it may be experiencing an outburst, which might be making it appear 5 to 10 magnitudes brighter than normal.
Meanwhile, Warren Offutt, a New Mexico neighbor of Hale, used his 24-inch reflector and a CCD to record a "spiral coma," an appearance typical of Comet Schwassmann-Wachmann 1 after its own outburst. Moreover, Offutt says the new comet has shrunk and dimmed a little in the past week. SKY & TELESCOPE columnist John Bortle notes that when an outburst occurs in a comet, a second outburst sometimes occurs about 30 days later. Bortle was intrigued by the comet's fan-shaped head when he observed it on July 31.
According to [analysis], the comet will reach perihelion [point in its orbit nearest the sun] in March or April of 1997, just inside the Earth's orbit. It will grace the predawn sky for northern observers that spring, but how bright it will get is still anybody's guess. For now it's magnitude 10 or 11 and crossing Sagittarius. Here are Hale-Bopp's 2000 coordinates for 0 hours Universal Time:
R.A. (2000) Decl.
August 1 18h 38.0m -31d 55'
August 6 18h 34.7m -31d 46'
August 11 18h 31.7m -31d 35'
Original file name: .CNI - Comet Hale-Bopp 8.7
This file was converted with TextToHTML - (c) Logic n.v.