| Full
size picture of cluster
HOT WHITE DWARF SHINES IN YOUNG STAR CLUSTER
A dazzling "jewelbox" collection of over 20,000 stars can be seen
in crystal clarity in this NASA Hubble Space Telescope image,
taken with the Wide Field Planetary Camera 2.
The young (40 million year old) cluster, called NGC 1818, is 164,000
light-years away in the Large Magellanic Cloud (LMC), a satellite
galaxy of our Milky Way. The LMC, a site of vigorous current star
formation, is an ideal nearby laboratory for studying stellar
evolution.
The circled star is a young white dwarf star which has only very
recently formed following the burnout of a red giant. Based on
this observation astronomers conclude that the red giant
progenitor star was 7.6 times the mass of our Sun. Previously,
astronomers have estimated that stars anywhere from 6 to 10 solar
masses would not just quietly fade away as white dwarfs but
abruptly self-destruct in torrential explosions.
Hubble can easily resolve the star in the crowded cluster,
and detect it's intense blue-white glow from a sizzling surface
temperature of 180,000 degrees Fahrenheit.
IMAGE DATA
date taken: December 1995
wavelenghth: natural color reconstruction
from three filters (I,B,U)
field of view 100 light-years, 2.2 arc minutes
pixel resolution: 0.1 arcsec/pixel for the WFC,
0.05 for the smaller PC
TARGET DATA
name NGC 1818
distance 164,000 light-years
constellation: Dorado
age 40,000,000 years
class: rich star cluster
apparent magnitude: 9.7
apparent diameter: 7 arc minutes
Credit: Rebecca Elson and Richard Sword, IoA Cambridge UK, and NASA
***(original WFPC2 image courtesy J. Holtzmann, Arizona State U)***
The images are from the Archive.
The PI on the original proposal was J. Westphal, Caltech.
Credit: Rebecca Elson and Richard Sword, IoA Cambridge UK, and NASA
The picture of the LMC is courtesy of
C. Smith,
based on images from
G. Bothun & I. Thompson.
Last updated 07/03/98
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