Highlights from VISTA's view of the Small Magellanic Cloud
The location of the Small Magellanic Cloud in the constellation of Tucana
Videos
ESOcast 105 Light: Starstruck by the Small Magellanic Cloud (4K UHD)
A close-up look at VISTA's view of the Small Magellanic Cloud
Comparison of the Small Magellanic Cloud in infrared and visible light
The Small Magellanic Cloud galaxy is a
striking feature of the southern sky even to the unaided eye. But
visible-light telescopes cannot get a really clear view of what is in
the galaxy because of obscuring clouds of interstellar dust. VISTA’s
infrared capabilities have now allowed astronomers to see the myriad of
stars in this neighbouring galaxy much more clearly than ever before.
The result is this record-breaking image — the biggest infrared image
ever taken of the Small Magellanic Cloud — with the whole frame filled
with millions of stars.
The Small Magellanic Cloud (SMC) is a dwarf galaxy, the more petite twin of the Large Magellanic Cloud (LMC). They are two of our closest galaxy neighbours in space — the SMC lies about 200 000 light-years away, just a twelfth of the distance to the more famous Andromeda Galaxy. Both are also rather peculiarly shaped, as a result of interactions with one another and with the Milky Way itself.
Their relative proximity to Earth makes the Magellanic Clouds ideal candidates for studying how stars form
and evolve. However, while the distribution and history of star
formation in these dwarf galaxies were known to be complex, one of the
biggest obstacles to obtaining clear observations of star formation in
galaxies is interstellar dust. Enormous clouds of these tiny grains scatter and absorb some of the radiation
emitted from the stars — especially visible light — limiting what can
be seen by telescopes here on Earth. This is known as dust extinction.
The SMC is full of dust, and the visible light emitted by its stars
suffers significant extinction. Fortunately, not all electromagnetic
radiation is equally affected by dust. Infrared
radiation passes through interstellar dust much more easily than
visible light, so by looking at the infrared light from a galaxy we can
learn about the new stars forming within the clouds of dust and gas.
VISTA, the Visible and Infrared Survey Telescope, was designed to image infrared radiation. The VISTA Survey of the Magellanic Clouds
(VMC) is focused on mapping the star formation history of the SMC and
LMC, as well as mapping their three-dimensional structures. Millions of
SMC stars have been imaged in the infrared thanks to the VMC, providing
an unparalleled view almost unaffected by dust extinction.
The whole frame of this massive image is filled with stars belonging
to the Small Magellanic Cloud. It also includes thousands of background
galaxies and several bright star clusters, including 47 Tucanae at the
right of the picture, which lies much closer to the Earth than the SMC.
The zoomable image will show you the SMC as you have never seen it before!
The wealth of new information in this 1.6 gigapixel image (43 223 x
38 236 pixels) has been analysed by an international team led by Stefano
Rubele of the University of Padova. They have used cutting-edge stellar models to yield some surprising results.
The VMC has revealed that most of the stars within the SMC formed far
more recently than those in larger neighbouring galaxies. This early
result from the survey is just a taster of the new discoveries still to
come, as the survey continues to fill in blind spots in our maps of the
Magellanic Clouds.
More Information
This research was presented in the paper "The VMC survey – XIV. First
results on the look-back time star formation rate tomography of the
Small Magellanic Cloud", in the journal Monthly Notices of the Royal Astronomical Society.
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ambitious programme focused on the design, construction and operation of
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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 a major partner in ALMA, the largest astronomical
project in existence. And on Cerro Armazones, close to Paranal, ESO is
building the 39-metre Extremely Large Telescope, the ELT, which will
become “the world’s biggest eye on the sky”.
Links
Contacts
Maria-Rosa Cioni
Leibniz-Institut für Astrophysik Potsdam (AIP)
Potsdam, Germany
Tel: +49 331 7499 651
Email: mcioni@aip.de
Richard Hook
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org
