Near the end of May, Comet C/2011 L4 PanSTARRS passed through a chance alignment of its orbital plane with Earth's, revealing a long antitail
pointing back toward the Sun.
Hornoch, Lelekovice, Czech Republic, reported observations (0.35m reflector + CCD) of an antitail
on several occasions during April and May: April 24.89 UT, 4'.0 long in p.a.
and then there was a spike, which was going straight forward and it was heading for the Sun." This sunward spike, or antitail
, had not been seen on Kohoutek before, and the astronauts debated if it was real or an illusion.
My third memorable one, C/1990 K1, put on a nice performance in August and September 1990, brightening to 3rd magnitude as it cruised the Milky Way and growing a broad antitail
the following year.
We could see not only the comet's thin, 30cents-long ion tail but also a rare and unexpected 10cents-long antitail
, one that appeared to point toward the Sun instead of away from it.
It had a tail that extended nearly 30 [degrees], as well as a bright, spike-shaped antitail
half as long.
This almost 2 [degrees] -long antitail
appeared broad and diffuse (see page 33).
The comet also exhibited an antitail
the likes of which had never been seen.
Sekanina predicts there will be no Sunward-pointing antitail
in late March, given the geometry of the flyby.
(With just a little extra effort you can improve your results dramatically, as discussed later.) You might even catch something of scientific value - a disconnection in the comet's tail, a sudden brightening, or the appearance of an antitail
At that time our view was directed upward at the comet's "underbelly." Visually, the directions of the antitail
and normal tail diverged by approximately 150 [degrees], with the former preceding the comet's head.
Just past perihelion and on its way out of the solar system, this comet surprised me by displaying a beautiful antitail
-- one that projects toward the Sun.