The globular star cluster NGC 6362
The globular star cluster NGC 6362 in the constellation of Ara (The Altar)
Wide-field view of the sky around the globular cluster NGC 6362
Hubble image of the globular star cluster NGC 6362
Comparison of views of the globular star cluster NGC 6362 from WFI and Hubble
Videos
Zooming in on the globular star cluster NGC 6362
Panning across the globular star cluster NGC 6362
This colourful view of the globular star cluster NGC 6362 was captured by the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. This new picture, along with a new image of the central region from the NASA/ESA Hubble Space Telescope, provide the best view of this little-known cluster ever obtained. Globular clusters are mainly composed of tens of thousands of very ancient stars, but they also contain some stars that look suspiciously young.
Globular star clusters are among the oldest objects in the Universe,
and NGC 6362 cannot hide its age in this picture. The many yellowish
stars in the cluster have already run through much of their lives and
become red giant stars. But globular clusters are not static relics from
the past — some curious stellar activities are still going on in these
dense star cities.
For instance, NGC 6362 is home to many blue stragglers — old stars that really do succeed in passing for a younger age. All
of the stars in a globular cluster formed over a fairly short period
of time, typically about 10 billion years ago for most globulars.
Yet blue stragglers are bluer and more luminous — and hence more
massive — than they should be after ten billion years of stellar
evolution. Blue stars are hot and consume their fuel quickly, so if
these stars had formed about ten billion years ago, then they should
have fizzled out long ago. How did they survive?
Astronomers are keen to understand the secret of the youthful
appearance of blue stragglers. Currently, there are two main theories:
stars colliding and merging, and a transfer of material between two
companion stars. The basic idea behind both of these options is that the
stars were not born as big as we see them today, but that they received
an injection of extra material at some point during their lifetimes and
this then gave them a new lease of life.
Although less well known than some brighter globular clusters, NGC
6362 holds much that is of interest to astronomers and has been well
studied over the years. It was selected as one of the 160 stellar fields
for the Pre-FLAMES Survey — a preliminary survey conducted between 1999
and 2002 using the 2.2-metre telescope at La Silla to find suitable
stars for follow-up observations with the VLT’s spectroscopic instrument
FLAMES. The picture here comes from data collected as part of this
survey.
The new image shows the entire cluster against a rich background of
the carpet of stars in the Milky Way. The central parts of NGC 6362 have
also been studied in detail
by the NASA/ESA Hubble Space Telescope. The Hubble view shows a much
smaller area of sky in much greater detail. The two views — one
wide-angle and one zoomed in — complement each other perfectly.
This brilliant ball of stars lies in the southern constellation of
Ara (The Altar). It can be easily seen in a small telescope. It was
first spotted in 1826 by the Scottish astronomer James Dunlop using a
22-centimetre telescope in Australia.
More information
The year 2012 marks the 50th anniversary of
the founding of the European Southern Observatory (ESO). ESO is the
foremost intergovernmental astronomy organisation in Europe and the
world’s most productive astronomical observatory. 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”.
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, La Silla, Paranal, E-ELT and Survey Telescopes Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org
