
This image of Comet Hergenrother, taken by the Gemini telescope on Nov. 2, 2012, shows several distinct pieces near the comet's core.
Amateur and professional astronomers have been following Comet Hergenrother for several weeks, noting some impressive outbursts of comet dust as it passed through our neck of the cosmic woods. Now it appears that the icy wanderer's days may be numbered.
"Comet Hergenrother is splitting apart," Rachel Stevenson, a post-doctoral fellow at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "Using the Gemini North Telescope on top of Mauna Kea, Hawaii, we have resolved that the nucleus of the comet has separated into at least four distinct pieces, resulting in a large increase in dust material in its coma."
With more material to reflect sunlight, Hergenrother's coma - the diffuse envelope around its core - has also brightened a great deal, researchers said.
"The comet fragments are considerably fainter than the nucleus," said Caltech's James Bauer, deputy principal investigator for NASA's asteroid-hunting NEOWISE mission, which used observations from the agency's Wide-field Infrared Survey Explorer spacecraft, or WISE. "This is suggestive of chunks of material being ejected from the surface."
One of the newly created comet fragments has also developed its own tail, which runs roughly parallel to Hergenrother's main tail, researchers said.
The comet's breakup was first spotted on Oct. 26, by a team of astronomers from Italy's Remanzacco Observatory who were using the Faulkes Telescope North in Hawaii. Since then, many other groups have trained their instruments on Hergenrother to watch the process unfold.
The comet was discovered in November 1998 by Carl Hergenrother. It completes one lap around the sun every 6.9 years or so. Comet Hergenrother's orbit is well understood; neither the iceball nor its newly formed pieces pose a threat to Earth, researchers say.
Hergenrother is fairly faint, requiring a large telescope to be viewed in any detail. The comet can currently be seen between the constellations of Andromeda and Lacerta, scientists say.
















There is a good reason for and it was not just a 'splitting', but rather (almost certainly) a pretty heavy 'explosion' (they missed to observe) due to the electrical stresses in the comet's nucleus as the (highly negatively charged) body first:
- entered the heliosphere
- then (checking its recent orbital data):
Distance from Sun: 1.484 AU
Perihelion: 1.415 AU (1-Oct-2012)
Eccentricity: 0.609449
Inclination to ecliptic 21.9°
it seems, it must have been crossing the ecliptic (max. electric
stress!) when the 'split' happened.
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"With more material to reflect sunlight, Hergenrother's coma -
the diffuse envelope around its core - has also brightened"
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It's not the 'increase of the material' (what a 'material increase' they
are talking about; it's _constant_!) that makes the sunlight reflecting; the 'diffuse envelope' around (s. picture) is a result of the local
increase of the plasma density (after the discharge) resulting in its own glowing !...