Wide-field view of the sky around the dark nebula LDN 483
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Dark cloud obscures hundreds of background stars
Some of the stars appear to be missing in
this intriguing new ESO image. But the black gap in this glitteringly
beautiful starfield is not really a gap, but rather a region of space
clogged with gas and dust. This dark cloud is called LDN 483 — for Lynds
Dark Nebula 483. Such clouds are the birthplaces of future stars. The
Wide Field Imager, an instrument mounted on the MPG/ESO 2.2-metre
telescope at ESO's La Silla Observatory in Chile, captured this image of
LDN 483 and its surroundings.
LDN 483 [1] is located about 700 light-years away in the constellation of Serpens (The
Serpent). The cloud contains enough dusty material to completely block
the visible light from background stars. Particularly dense molecular clouds, like LDN 483, qualify as dark nebulae
because of this obscuring property. The starless nature of LDN 483 and
its ilk would suggest that they are sites where stars cannot take root
and grow. But in fact the opposite is true: dark nebulae offer the most
fertile environments for eventual star formation.
Astronomers studying star formation in LDN 483 have discovered some
of the youngest observable kinds of baby stars buried in LDN 483’s
shrouded interior. These gestating stars can be thought of as still
being in the womb, having not yet been born as complete, albeit
immature, stars.
In this first stage of stellar development, the star-to-be is just a
ball of gas and dust contracting under the force of gravity within the
surrounding molecular cloud. The protostar is still quite cool — about
–250 degrees Celsius — and shines only in long-wavelength submillimetre
light [2]. Yet temperature and pressure are beginning to increase in the fledgling star’s core.
This earliest period of star growth lasts a mere thousands of years,
an astonishingly short amount of time in astronomical terms, given that
stars typically live for millions or billions of years. In the following
stages, over the course of several million years, the protostar will
grow warmer and denser. Its emission will increase in energy along the
way, graduating from mainly cold, far-infrared light to near-infrared
and finally to visible light. The once-dim protostar will have then
become a fully luminous star.
As more and more stars emerge from the inky depths of LDN 483, the
dark nebula will disperse further and lose its opacity. The missing
background stars that are currently hidden will then come into view —
but only after the passage of millions of years, and they will be
outshone by the bright young-born stars in the cloud [3].
Notes
[1] The Lynds Dark Nebula catalogue
was compiled by the American astronomer Beverly Turner Lynds, and
published in 1962. These dark nebulae were found from visual inspection
of the Palomar Sky Survey photographic plates.
[3] Such a young open star cluster can be seen here, and a more mature one here.
More Information
ESO is the foremost intergovernmental astronomy organisation in Europe
and the world’s most productive ground-based astronomical observatory by
far. It is supported by 15 countries: Austria, Belgium, Brazil, the
Czech Republic, Denmark, France, Finland, Germany, Italy, the
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Kingdom. ESO carries out an ambitious programme focused on the design,
construction and operation of powerful ground-based observing facilities
enabling astronomers to make important scientific discoveries. ESO also
plays a leading role in promoting and organising cooperation in
astronomical research. ESO operates three unique world-class observing
sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO
operates the Very Large Telescope, the world’s most advanced
visible-light astronomical observatory and two survey telescopes. VISTA
works in the infrared and is the world’s largest survey telescope and
the VLT Survey Telescope is the largest telescope designed to
exclusively survey the skies in visible light. ESO is the European
partner of a revolutionary astronomical telescope ALMA, the largest
astronomical project in existence. ESO is currently planning the
39-metre European Extremely Large optical/near-infrared Telescope, the
E-ELT, which will become “the world’s biggest eye on the sky”.
Links
- Photos of the MPG/ESO 2.2-metre telescope
- Other photos taken with the MPG/ESO 2.2-metre telescope
- Photos of La Silla
Contacts
Richard Hook
ESO education and Public Outreach Department
Garching bei München, Germany
Tel: +49 89 3200 6655
Email: rhook@eso.org
Source: ESO
