[Prev][Next][Index][Thread]
(meteorobs) A new naked-eye comet next summer?
Using the rather short arc computed from the observations, a preliminary
orbit for Comet LINEAR -- C/1999 S4 has been worked out. From this I have
developed an ephemeris for June, July and August of next year. The comet
will then be a late-night object -- rising out of the northeast during June
and early July -- as it moves from Triangulum, through Andromeda and into
Perseus. Between July 5 and 15, for those living north of latitude 40
degrees North, the comet will become circumpolar, as it moves through
Perseus, Camelopardalis and Ursa Major.
On July 16, the comet will be 0.720 a.u. from the Sun and 0.374 a.u. from
Earth. Using a fourth-power law formula, this would correspond to a
magnitude +3.5. However, since the comet orbit is still indistinguishable
from a parabola, we cannot be sure if it is an Oort-cloud comet (and making
its first visit to the Sun's vicinity). If this is the case, then the
comet's brightening could slow dramatically by next spring (a la comets
Cunningham, Kohoutek and Austin) and possibly not even reach sixth magnitude.
If it has been here before -- like Hale-Bopp or Hyakutake -- it should
manage to get to +3.5 . . . "possibly" a magnitude or so brighter. It is
still much too early in the ball game to tell. Also take note of the fact
that a total lunar eclipse of extreme duration (totality = 107 minutes) will
take place for much of Asia and the Pacific on July 15-16!
After July 16, the comet -- now an evening object in the western twilight
sky -- heads south across Leo Minor, Leo and Virgo. Perihelion will come on
July 18, its distance from the Sun at 0.71953 a.u. It will cross the
celestial equator on July 30, at which time it will become increasingly
difficult to follow from mid-northern viewing sites.
-- joe rao
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html