Light Echoes from V838 Mon
Explanation:
What caused this outburst of V838 Mon?
For
reasons unknown, star
V838 Mon's
outer surface suddenly greatly expanded with the
result that it became the brightest star in the entire
Milky Way Galaxy in January 2002.
Then, just as suddenly, it faded.
A
stellar flash
like this has never been seen before --
supernovas
and
novas expel matter out into space.
Although the
V838 Mon flash appears to expel material into space, what is seen in the
above image from the
Hubble Space Telescope is actually
an outwardly moving
light echo of the bright flash.
In a
light echo, light from the flash is
reflected by successively
more distant rings
in the complex array of ambient
interstellar dust that already surrounded the star.
V838 Mon lies about 20,000
light years away toward the
constellation of the
unicorn
(
Monoceros), while the
light echo above spans about six
light years in diameter.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
