Triangulum Galaxy Snapped by VST

 PR Image eso1424a

VST snaps a very detailed view of the Triangulum Galaxy

PR Image eso1424b

Messier 33 in the northern constellation of Triangulum

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Wide-field view of the sky around Messier 33

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Videos

PR Video eso1424a

Zooming in on the Triangulum Galaxy

PR Video eso1424b

A close-up look at the Triangulum Galaxy

The VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile has captured a beautifully detailed image of the galaxy Messier 33. This nearby spiral, the second closest large galaxy to our own galaxy, the Milky Way, is packed with bright star clusters, and clouds of gas and dust. The new picture is amongst the most detailed wide-field views of this object ever taken and shows the many glowing red gas clouds in the spiral arms with particular clarity.

Messier 33, otherwise known as NGC 598, is located about three million light-years away in the small northern constellation of Triangulum (The Triangle). Often known as the Triangulum Galaxy it was observed by the French comet hunter Charles Messier in August 1764, who listed it as number 33 in his famous list of prominent nebulae and star clusters. However, he was not the first to record the spiral galaxy; it was probably first documented by the Sicilian astronomer Giovanni Battista Hodierna around 100 years earlier.

Although the Triangulum Galaxy lies in the northern sky, it is just visible from the southern vantage point of ESO’s Paranal Observatory in Chile. However, it does not rise very high in the sky. This image was taken by the VLT Survey Telescope (VST), a state-of-the-art 2.6-metre survey telescope with a field of view that is twice as broad as the full Moon. This picture was created from many individual exposures, including some taken through a filter passing just the light from glowing hydrogen, which make the red gas clouds in the galaxies spiral arms especially prominent.

Among the many star formation regions in Messier 33’s spiral arms, the giant nebula NGC 604 stands out. With a diameter of nearly 1500 light-years, this is one of the largest nearby emission nebulae known. It stretches over an area 40 times the size of the visible portion of the much more famous — and much closer — Orion Nebula.

The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, which includes the Milky Way, the Andromeda Galaxy, and about 50 other smaller galaxies. On an extremely clear, dark night, this galaxy is just visible with the unaided eye, and is considered to be the most distant celestial object visible without any optical help. Viewing conditions for the very patient are only set to improve in the long-term: the galaxy is approaching our own at a speed of about 100 000 kilometres per hour.

A closer look at this beautiful new picture not only allows a very detailed inspection of the star-forming spiral arms of the galaxy, but also reveals the very rich scenery of the more distant galaxies scattered behind the myriad stars and glowing clouds of NGC 598.

More information

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”.

Links

• Photos of the VST
• The VLT and Messier 33

Contacts

Richard Hook
ESO Public Information Officer
Garching bei München, Germany

Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

Source: ESO

The Supernovae of Triangulum

An optical image of the Triangulum Galaxy.

Scientists have used the Chandra X-ray Observatory to study and characterize all of the known supernova remnants in this galaxy. Credit: Paul Mortfield, Stefano Cancelli

The Triangulum Galaxy, at a distance of only 2.6 million light-years, is one of the closest spiral galaxies to earth. It is also the third largest member of our galactic neighborhood (after Andromeda and our own Milky Way). Because we see it nearly face on and so have such a clear view of its stars, it has long been an obvious choice for astronomers wanting to characterize the complete population of supernovae in a galaxy.

Supernovae are the explosive deaths of massive stars. These cataclysms disburse into space all the chemical elements produced by the nuclear reactions inside the progenitor stars, and chemical enrichment alone is reason enough to make supernovae objects of intense study. In addition, though, supernovae are so bright that they can be seen at very large (cosmological) distances. If a supernova's intrinsic brightness is known from its basic character, its distance (and the distance of its host galaxy) can be determined from its apparent brightness. This presumes that we understand supernovae and their possible varieties. By studying the character of an entire population of supernovae in a single galaxy, like the Triangulum, and the remnants they leave behind, astronomers can test and refine their understanding of supernovae.

In the Milky Way there have been at least five supernovae in the last thousand years or so. All of their remnants are detectable today as X-ray sources, and their differing properties reflect their diverse characters. For example, while four these five remnants have comparatively modest gas temperatures, the Crab Nebula remnant hosts a pulsar and its gas is much hotter. CfA astronomers Terrance Gaetz, Bob Kirshner, Paul Plucinsky, and Ralph Tullmann, together with a team of twelve colleagues, used the Chandra X-ray Observatory to undertake the first deep X-ray study of the Triangulum Galaxy.

The scientists detected eighty-two of the 137 known supernova remnants, making this the largest sample of supernova remnants detected both in optical and X-rays in any galaxy, including the Milky Way. They developed a new morphological classification scheme to relate optical and X-ray sources, reported that they find no direct analogs to some of the bright, recent remnants in the Milky Way, and concluded that there are no strong correlations between the X-ray brightness of these remnants and their brightnesses at other wavelengths. The results refine our basic understanding of supernovae, and help clarify the range of X-ray properties they have.