Bright Stars, Dim Galaxy
Explanation:
These two clusters of bright, newly formed stars surrounded
by a glowing nebula lie 10 million light years away in the dim,
irregular galaxy cataloged as NGC 2366.
The Hubble Space Telescope image shows that the youngest cluster,
the bottom one at about 2 million years old,
is still surrounded by the gas and dust cloud it condensed from, while
powerful stellar winds from the stars
in the older cluster at the top (4-5 million years old),
have begun to clear away its central areas giving the entire nebula
an apparent hook shape.
Compared to the sun, the stars in these clusters
are massive and short lived.
The brightest one, near the tip of the hook, is a rare Luminous Blue Variable
with 30 to 60 times the mass of the sun - similar to the erruptive
Eta Carina variable in our own Milky Way.
Stars this massive
are extremely variable.
A comparison with ground based images indicates that in three
years this star's brightness increased by about 40 times making it currently
the brightest star in this dim galaxy.
Studies of such distant and diverse galaxies yield clues to the relationships
of star formation and galactic evolution.
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.
