The star cluster NGC 3572 and its dramatic surroundings
The star cluster NGC 3572 in the constellation of Carina
Wide-field view of the sky around the star cluster NGC 3572
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A close look at the star cluster NGC 3572 and its dramatic surroundings
Astronomers at ESO have captured the best
image so far of the curious clouds around the star cluster NGC 3572.
This new image shows how these clouds of gas and dust have been sculpted
into whimsical bubbles, arcs and the odd features known as elephant
trunks by the stellar winds flowing from this gathering of hot young
stars. The brightest of these cluster stars are much heavier than the
Sun and will end their short lives as supernova explosions.
Most stars do not form alone, but with many siblings that are created
at about the same time from a single cloud of gas and dust. NGC 3572,
in the southern constellation of Carina (The Keel), is one of these
clusters. It contains many hot young blue-white stars that shine
brightly and generate powerful stellar winds that tend to gradually
disperse the remaining gas and dust from their surroundings. The glowing
gas clouds and accompanying cluster of stars are the subjects of a new
picture from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at
ESO’s La Silla Observatory in Chile [1].
In the lower part of the image a big chunk of the molecular cloud
that gave birth to these stellar youngsters still can be seen. It has
been dramatically affected by the powerful radiation coming from its
smoldering offspring. The radiation not only makes it glow with a
characteristic hue, but also sculpts the clouds into amazingly
convoluted shapes, including bubbles, arcs and the dark columns that
astronomers call elephant trunks [2].
A strange feature captured in this image is the tiny ring-like nebula
located slightly above the centre of the image. Astronomers still are a
little uncertain about the origin of this curious feature. It is
probably a dense leftover from the molecular cloud that formed the
cluster, perhaps a bubble created around a very bright hot star. But
some authors have considered that it may be some kind of oddly shaped
planetary nebula — the remnants of a dying star [3].
Stars born inside a cluster may be siblings, but they are not twins.
They have almost the same age, but differ in size, mass, temperature,
and colour. The course of a star's life is determined largely by its
mass, so a given cluster will contain stars in various stages of their
lives, giving astronomers a perfect laboratory in which they can study
how stars evolve [4].
These gangs of young stars stick together for a relatively short
time, typically tens or hundreds of millions of years. They are
gradually disbanded by gravitational interactions, but also because the
most massive stars are short-lived, burning through their fuel quickly
and ultimately ending their lives in violent supernova explosions, thus
contributing to the dispersion of the remaining gas and stars in the
cluster.
Notes
[1] The data used to create this
picture were obtained by a team led by ESO astronomer Giacomo Beccari.
They used the power of the Wide Field Imager to study the physics of
protoplanetary discs in the young stars in NGC 3572. They were surprised
to find that this cluster contains stars older than ten million years
that are still unambiguously undergoing mass accretion and, therefore,
must still be surrounded by discs. This proves that the star formation
in NGC 3572 has been ongoing for at least 10–20 million years and would
imply that the planet formation process could proceed on much longer
timescales than previously thought.
[2] The most famous examples of such elephant trunk
features are the Pillars of Creation in the Eagle Nebula, which were
captured in exquisite detail by the NASA/ESA Hubble Space Telescope (http://www.spacetelescope.org/images/opo9544a/).
[3] When a Sun-like star uses up all its fuel, it
puffs its outer layers off into the surrounding space. The hot remains
of the star continue to shine strongly into this material, creating
beautiful but short-lived glowing shells of ionised gas and forming a
so-called planetary nebula. This historical name is only related to the
appearance of the object in a small telescope, not to a physical
relation to a planet.
[4] The lifetime of a star depends dramatically on
how heavy it is. A star fifty times more massive than the Sun will have a
life of only a few million years, the Sun will live for about ten
billion years whereas low-mass red dwarf stars can live for trillions of
years — much longer than the current age of the Universe.
More information
ESO is the foremost intergovernmental
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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
- Handback of 2.2-metre telescope
- Images taken with the MPG/ESO 2.2-metre telescope
- Images of the MPG/ESO 2.2-metre telescope
- ESO press releases with results from the MPG/ESO 2.2-metre telescope
Contacts
Richard HookESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org
Giacomo Beccari
ESO
Santiago, Chile
Tel: +56 (0) 2 2463 3096
Email: gbeccari@eso.org
