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A close-up look at the stellar nursery IC 2944 and Thackeray's Globules
With this new view (eso1322a) of a spectacular
stellar nursery ESO is celebrating 15 years of the Very Large Telescope —
the world's most advanced optical instrument. This picture reveals
thick clumps of dust silhouetted against the pink glowing gas cloud
known to astronomers as IC 2944. These opaque blobs resemble drops of
ink floating in a strawberry cocktail, their whimsical shapes sculpted
by powerful radiation coming from the nearby brilliant young stars.
This new picture celebrates an important anniversary for the Very
Large Telescope – it is fifteen years since the first light on the first
of its four Unit Telescopes, on 25 May 1998. Since then the four
original giant telescopes have been joined by the four small Auxiliary
Telescopes that form part of the VLT Interferometer (VLTI). The VLT is
one of the most powerful and productive ground-based astronomical
facilities in existence. In 2012 more than 600 refereed scientific
papers based on data from the VLT and VLTI were published (ann13009).
Interstellar clouds of dust and gas are the nurseries where new stars
are born and grow. The new picture shows one of them, IC 2944, which
appears as the softly glowing pink background . This image is the sharpest view of the object ever taken from the ground .
The cloud lies about 6500 light-years away in the southern
constellation of Centaurus (The Centaur). This part of the sky is home
to many other similar nebulae that are scrutinised by astronomers to
study the mechanisms of star formation.
Emission nebulae like IC 2944 are composed mostly of hydrogen gas
that glows in a distinctive shade of red, due to the intense radiation
from the many brilliant newborn stars. Clearly revealed against this
bright backdrop are mysterious dark clots of opaque dust, cold clouds
known as Bok globules. They are named after the Dutch-American
astronomer Bart Bok, who first drew attention to them in the 1940s as
possible sites of star formation. This particular set is nicknamed the
Thackeray Globules .
Larger Bok globules in quieter locations often collapse to form new
stars but the ones in this picture are under fierce bombardment from the
ultraviolet radiation from nearby hot young stars. They are both being
eroded away and also fragmenting, rather like lumps of butter dropped
into a hot frying pan. It is likely that Thackeray’s Globules will be
destroyed before they can collapse and form stars.
Bok globules are not easy to study. As they are opaque to visible
light it is difficult for astronomers to observe their inner workings,
and so other tools are needed to unveil their secrets — observations in
the infrared or in the submillimetre parts of the spectrum, for example,
where the dust clouds, only a few degrees over absolute zero, appear
bright. Such studies of the Thackeray globules have confirmed that there
is no current star formation within them.
This region of sky has also been imaged in the past by the NASA/ESA Hubble Space Telescope (opo0201a). This new view from the FORS instrument on ESO’s Very Large Telescope at the Paranal Observatory in northern Chile  covers a wider patch of sky than Hubble and shows a broader landscape of star formation.
 The nebula IC 2944 is associated
with the bright star cluster IC 2948 and both of these names are also
sometimes associated with the whole region. Many of the bright cluster
stars appear in this picture.
 The seeing of the blue image in this colour
combination was better than 0.5 arcseconds, exceptionally good for a
 They were discovered from South Africa by the English astronomer A. David Thackeray in 1950.
 This picture comes from the ESO Cosmic Gems programme,
an outreach initiative to produce images of interesting, intriguing or
visually attractive objects using ESO telescopes, for the purposes of
education and public outreach. The programme makes use of telescope time
that cannot be used for science observations. All data collected may
also be suitable for scientific purposes, and are made available to
astronomers through ESO’s science archive.
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 Netherlands, Portugal, Spain,
Sweden, Switzerland and the United 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”.