Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.arcetri.astro.it/~palla/ANDREAIMMAGINI/ViaLattea/9816.txt Дата изменения: Fri Mar 2 18:51:47 2001 Дата индексирования: Sat Dec 22 08:24:37 2007 Кодировка: Поисковые слова: m 8

FOR RELEASE: 9:00 a.m. (EDT) April 9, 1998

PHOTO NO.: STScI-PRC98-16



HOT WHITE DWARF SHINES IN YOUNG STAR CLUSTER

A dazzling "jewel-box" collection of over 20,000 stars can be seen in
crystal clarity in this NASA Hubble Space Telescope image, taken with
the Wide Field and 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.

In the cluster, astronomers have found 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 its
intense blue-white glow from a sizzling surface temperature of 50,000
degrees Fahrenheit.


IMAGE DATA

Date taken: December 1995
Wavelength: natural color reconstruction from three filters (I,B,U)
Field of view: 100 light-years, 2.2 arc minutes


TARGET DATA

Name: NGC 1818
Distance: 164,000 light-years
Constellation: Dorado
Age: 40 million years
Class: Rich star cluster
Apparent magnitude: 9.7
Apparent diameter: 7 arc minutes

Credit: Rebecca Elson and Richard Sword, Cambridge UK, and NASA
(Original WFPC2 image courtesy J. Westphal, Caltech)

Image files are available electronically via the World Wide Web at:
http://oposite.stsci.edu/pubinfo/1998/16 and via links in
http://oposite.stsci.edu/pubinfo/latest.html or
http://oposite.stsci.edu/pubinfo/pictures.html.


GIF and JPEG images are available via anonymous ftp to oposite.stsci.edu in
/pubinfo/gif/9816.gif and /pubinfo/jpeg/9816.jpg.