CELESTIAL SEASON'S GREETINGS FROM HUBBLE
Swirls of gas and dust reside in this ethereal-looking region
of star formation imaged by NASA's Hubble Space Telescope. This
majestic view, located in the Large Magellanic Cloud (LMC),
reveals a region where low-mass, infant stars and their much
more massive stellar neighbors reside. A shroud of blue haze
gently lingers amid the stars.
Known as LH 95, this is just one of the hundreds of star-forming
systems, called associations, located in the LMC some 160,000
light-years distant. Earlier ground-based observations of such
systems had only allowed astronomers to study the bright blue
giant stars present in these regions. With Hubble's resolution,
the low-mass stars can now be analyzed, which will allow for a
more accurate calculation of their ages and masses.
This detailed view of the star-forming association LH 95 was
taken with Hubble's Advanced Camera for Surveys and provides an
extraordinarily rich sample of newly formed low-mass stars. The
LMC is a galaxy with relatively small amounts of elements heavier
than hydrogen, giving astronomers an insight into star formation
in environments different than our Milky Way.
The largest stars within LH 95 - those with at least three times
the mass of the Sun - generate strong stellar winds and high
levels of ultraviolet radiation that heat the surrounding
interstellar gas. The result is a bluish nebula of glowing
hydrogen that continues to expand out into the molecular cloud
that originally collapsed to form these massive stars.
Some dense parts of this star-forming region are intact despite the
stellar winds, and can still be seen as dark dusty filaments in the
picture. Such dust lanes absorb parts of the blue light from the stars
behind them, making them appear redder. Other parts of the molecular
cloud have already contracted to turn into glowing groups of infant
stars, the fainter of which have a high tendency to cluster. This
deep Hubble image also reveals several large spiral and distant
galaxies decorating the background of LH 95.
This image of LH 95 is a composite of two filters that localize
visible (V) and infrared (I) light. Because of the color assignments
chosen, ionized hydrogen, which is visible within the V
filter, appears bluish. The choice of color assignment helps to
distinguish hot bright blue stars from cooler, less luminous red
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration
Acknowledgment: D. Gouliermis (Max Planck Institute for Astronomy, Heidelberg)