Explanation:
Like most other sungrazing comets, Comet Lovejoy (C/2011 W3)
was not expected to survive its
close encounter with the Sun.
But it did.
This image
from a coronograph
onboard the sun-staring SOHO spacecraft identifies the still
inbound
remnants of the tail, with the brilliant head or coma
emerging from
the solar glare on December 16.
The Sun's position, behind an occulting disk to block the overwhelming
glare, is indicated by the white circle.
Separated from its tail, Comet Lovejoy's coma is so bright it saturates
the camera's pixels creating the horizontal streaks.
Based on their orbits, sungrazer comets
are thought to belong to the Kreutz
family of comets, created by successive break ups from a single large
parent comet that passed very near the Sun in the twelfth century.
Most have been discovered with SOHO's cameras,
but unlike many sungrazers, this one was first spotted by Australian
astronomer Terry Lovejoy from an earth-based observatory.
Comet Lovejoy is estimated to have come within 120,000 kilometers
of the Sun's surface and likely had
a large cometary nucleus to have survived its intense
perihelion passage.
Remarkable videos of the encounter from
the Solar Dynamics Observatory
can
be found here.
