Comet Hale-Bopp Update
COMET HALE-BOPP UPDATE
Sky & Telescope News Bulletin
May 2, 1997
COMET-TAIL WATCH
Space scientists from NASA and the European Space Agency predict that the
ion tail of Comet Hale-Bopp will be particularly susceptible to the solar
wind's influence between April 28th and May 15th. They say the blue-
colored tail could show brightness changes, kinks, and perhaps moving
structures. Also possible are "disconnection events," when the ion tail
breaks off from the comet's coma and reforms a few hours later. Scientists
have issued this "tail watch" because the comet is now within 10 degrees
of the plane of the solar equator. In this region the outflowing solar
wind is gusty and the magnetic field irregular. When the plane is crossed
on May 3rd, the direction of the interplanetary magnetic field will
change. Amateur astronomers are encouraged to monitor the tail's
appearance carefully during this period. Interested observers can access
the comet watch home page at http://www-istp.gsfc.nasa.gov/istp/halebopp/
TWILIGHT FOR HALE-BOPP
Observers are having an interesting time pinning down the current
magnitude of Comet Hale-Bopp. Depending on whom you ask, this celebrated
comet has faded to anywhere from magnitude 0.0 to 1.0. However, it's still
a cinch to spot after sunset; it should be obvious about 20 degrees above
the west-northwestern horizon as soon as it gets dark.
MAY 4 -- SUNDAY
Comet Hale-Bopp is still in view this week, though it has shrunken and
faded in the last month. Look low in the west-northwest right at the end of
twilight. Bring binoculars!
MAY 5 -- MONDAY
Today Comet Hale-Bopp passes through the Earth's orbital plane, only
about 10 million miles outside the January part of our orbit. Too bad we're
not there now, to see the comet from 20 times closer than we did a month ago
when it was at its best!
MAY 8 -- THURSDAY
This evening the crescent Moon (now plainly visible) is paired with
Comet Hale-Bopp. Just as twilight ends, look low in the west-northwest. The
comet is about 4 or 5 degrees (about three finger-widths at arm's length)
to the Moon's upper right (as seen from North America). They're partway up
the horns of Taurus. Try binoculars.
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