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Gallery – The Sculptor Galaxy

Galaxy NGC 253

Bright regions of ongoing star formation are spread throughout the Sculptor Galaxy, which is pumping out new stars at a furious pace.

ELEVEN AND A HALF MILLION light-years away in the direction of the southern constellation Sculptor, lies the beautiful galaxy NGC 253. Also known as the Sculptor Galaxy, it has been given the names Silver Coin Galaxy or Silver Dollar Galaxy by amateur astronomers.

Indeed it is a popular target for amateurs, and can even be glimpsed through binoculars. It is one of the brightest galaxies in the sky after the Milky Way’s closest, big galactic neighbour, the Andromeda Galaxy.

But professional astronomers are interested in it too, having noted widespread active star formation within it, hence its other label as a “starburst” galaxy.

The many bright clumps dotted throughout the galaxy are “stellar nurseries” where hot, young stars have just ignited. The radiation streaming from these giant blue-white baby stars makes the surrounding hydrogen gas clouds glow brightly (green in this image).

NGC 253 was discovered by the German–British astronomer Caroline Herschel, the sister of the famed astronomer William Herschel, as she searched for comets in 1783.

The image was captured by the European Southern Observatory’s VLT Survey Telescope (VST), and is probably the most detailed wide-field view of this galaxy and its surroundings ever made.

As well as NGC 253, zooming in also reveals a very rich tapestry of much more distant galaxies far beyond NGC 253, a handful of which are marked on the enlargement below – there are many more:

Galaxy NGC 253

This enlargement shows a handful of background galaxies (marked with arrows) – there are many more.

The VST – Super survey telescope

This latest image of NGC 253 was taken during VST’s science verification phase of the European Southern Observatory’s VLT Survey Telescope (VST), when the telescope’s scientific performance is assessed before it enters operations.

The VST data are being combined with infrared images from another telescope called VISTA to identify the younger generations of stars in NGC 253.

VLT Survey Telescope

VLT Survey Telescope (VST)

This picture is more than 12,000 pixels across and the superb sky conditions at ESO’s Paranal Observatory, combined with the fine telescope optics, result in sharp star images over the entire image.

The VST is a 2.6-metre-diameter, wide-field survey telescope with a one-degree field of view — which means it can see an area of sky twice as broad as the full Moon.

The 268-megapixel camera OmegaCAM at its heart is designed to map the sky both quickly and with very fine image quality. VST is the largest telescope in the world designed to exclusively survey the sky in visible light, complementing ESO’s VISTA infrared survey telescope, also located at Paranal.

The VST programme is a joint venture between the INAF–Osservatorio Astronomico di Capodimonte, Naples, Italy and ESO.

Adapted from information issued by ESO / INAF-VST. Acknowledgement: A. Grado/L. Limatola/INAF-Capodimonte Observatory.

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Cosmic grandeur: the Sculptor Galaxy

Infrared view of galaxy NGC 253

NGC 253 is one of the closest galaxies to our own. At infrared wavelengths shown here, dust clouds in the galaxy’s spiral arms become nearly transparent and a host of cool, red stars can be seen.

  • Sculptor Galaxy, also known as NGC 253
  • 13 million light-years from Earth
  • “Starburst” galaxy, in the throes of massive star formation

A new image of the Sculptor Galaxy (NGC 253) has been taken with the European Southern Observatory (ESO) VISTA telescope at the Paranal Observatory in Chile as part of one of its first major observational campaigns.

By observing in infrared light, VISTA’s view is less affected by dust in the galaxy, and reveals a myriad of cooler, red stars, as well as a prominent elongated belt of stars across the central region.

NGC 253 is one of the brightest galaxies in the sky. It is prominent enough to be seen with good binoculars and was discovered by Caroline Herschel from England in 1783.

A spiral galaxy that lies about 13 million light-years away, it is the brightest member of a small collection of galaxies called the Sculptor Group, one of the closest such groupings to our own Local Group of galaxies.

Part of its visual prominence comes from its status as a “starburst galaxy”, one in the throes of rapid star formation.

Infrared and visible light views of galaxy NGC 253

Comparison of the infrared (top) and visible light (bottom) views.

NGC 253 is also very dusty, which obscures the view of many parts of the galaxy. Seen from Earth, the galaxy is almost edge on, with the spiral arms clearly visible in the outer parts, along with a bright core at its centre.

See the full-size image here.

As VISTA works at infrared wavelengths it can see right through most of the dust that is such a prominent feature of the Sculptor Galaxy when viewed in visible light. Huge numbers of cooler stars that are barely detectable with visible-light telescopes suddenly can be seen.

The VISTA view reveals most of what was hidden by the thick dust clouds in the central part of the galaxy and allows a clear view of a prominent elongated section, or “bar”, of stars across the nuclear region — a feature that is not seen in visible light pictures. The majestic spiral arms now spread over the whole disc of the galaxy.

Astronomers are peeling away some of the mysteries of the Sculptor Galaxy. They are studying the myriad cool, red giant stars in the halo that surrounds the galaxy, measuring the composition of some of NGC 253’s small dwarf satellite galaxies, and searching for as yet undiscovered new objects such as globular clusters and ultra-compact dwarf galaxies that would otherwise be invisible without the deep VISTA infrared images.

Adapted from information issued by ESO / J. Emerson / VISTA / Cambridge Astronomical Survey Unit.