Space
Phenomenon Imitates Art in Universe's Version of
van Gogh Painting
"Starry
Night," Vincent van Gogh's famous painting,
is renowned for its bold whorls of light sweeping
across a raging night sky. Although this image of
the heavens came only from the artist's restless
imagination, a new picture from NASA's Hubble Space
Telescope bears remarkable similarities to the van
Gogh work, complete with never-before-seen spirals
of dust swirling across trillions of miles of interstellar
space.
This image, obtained with the Advanced Camera for
Surveys on
February 8, 2004, is Hubble's latest view of an
expanding halo
of light around a distant star, named V838 Monocerotis
(V838 Mon).
The illumination of interstellar dust comes from
the red supergiant
star at the middle of the image, which gave off
a flashbulb-like
pulse of light two years ago. V838 Mon is located
about 20,000
light-years away from Earth in the direction of
the constellation
Monoceros, placing the star at the outer edge of
our Milky Way galaxy.
Called a light echo, the expanding illumination
of a dusty cloud around the star has been revealing
remarkable structures ever since the star suddenly
brightened for several weeks in early 2002. Though
Hubble has followed the light echo in several snapshots,
this new image shows swirls or eddies in the dusty
cloud for the first time. These eddies are probably
caused by turbulence in the dust and gas around
the star as they slowly expand away. The dust and
gas were likely ejected from the star in a previous
explosion, similar to the 2002 event, which occurred
some tens of thousands of years ago. The surrounding
dust remained invisible and unsuspected until suddenly
illuminated by the brilliant explosion of the central
star two years ago.
The Hubble telescope has imaged V838 Mon and its
light echo several times since the star's outburst
in January 2002, in order to follow the constantly
changing appearance of the dust as the pulse of
illumination continues to expand away from the star
at the speed of light. During the outburst event,
the normally faint star suddenly brightened, becoming
600,000 times more luminous than our Sun. It was
thus one of the most brightest stars in the entire
Milky Way, until it faded away again in April 2002.
The star has some similarities to a class of objects
called "novae," which suddenly increase
in brightness due to thermonuclear explosions at
their surfaces; however, the detailed behavior of
V838 Mon, in particular its extremely red color,
has been completely different from any previously
known nova.
Nature's own piece of performance art, this structure
will continue
to change its appearance in coming years as the
light from the
stellar outburst continues to propagate outward
and bounce off more
distant black clouds of dust. Astronomers expect
the echoes to
remain visible for at least the rest of the current
decade.
Image Credit: NASA and The Hubble Heritage Team
(AURA/STScI)
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