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Archive for March 28, 2013

New Radio Telescope In SA Will Also Shed New Light On The Earliest Moments Of The Universe: C-BASS South Commissioning At Hartebeesthoek


In the week that saw the release of the first results from the European Space Agency’s Planck satellite, astronomers at the Hartebeesthoek Radio Astronomy Observatory (HartRAO) near Johannesburg are working on a new radio telescope that will also shed new light on the very earliest moments of the universe.

The C-Band All-Sky Survey (C-BASS) is a project to map the sky in microwave (short-wavelength radio) radiation. Like Planck, it will survey the whole sky, mapping out how bright the sky is, and also the orientation of the waves (called polarization). While Planck observes very short wavelengths, C-BASS observes longer wavelengths that are actually easier to observe from the ground.

“Because we want to observe at these longer wavelengths, the C-BASS telescope has to be much bigger than the telescope on Planck,” explains South African C-BASS team member Charles Copley. “The C-BASS dish is over seven metres across – much too big to launch on a rocket.”

In order to observe the entire sky, C-BASS needs to use two different telescopes, one in the northern hemisphere and one in the southern hemisphere.

Full Story: http://www.ska.ac.za/releases/20130327.php

Sun Block For The Big Dog: Detection Of Titanium Oxide And Titanium Dioxide Around The Giant Star VY Canis Majoris


Credits: Molecule symbols: CDMS/T. Kamiński, Background image: NASA/ESA and R. Humphreys (University of Minnesota)

Credits: Molecule symbols: CDMS/T. Kamiński, Background image: NASA/ESA and R. Humphreys (University of Minnesota)

An international team of astronomers, including researchers from the Max Planck Institute for Radio Astronomy and from the University of Cologne, discovered two titanium oxides, TiO and TiO2, at radio wavelengths using telescope arrays in the USA and in France. The detection was made in the environment of VY Canis Majoris, a giant star close to the end of its life.

The discovery was made in the course of a study of a spectacular star, VY Canis Majoris or VY CMa for short, which is a variable star located in the constellation Canis Major (Greater Dog). “VY CMa is not an ordinary star, it is one of the largest stars known, and it is close the end of its life,” says Tomasz Kamiński from the Max Planck Institute for Radio Astronomy (MPIfR). In fact, with a size of about one to two thousand times that of the Sun, it could extend out to the orbit of Saturn if it were placed in the center of our Solar System.

The star ejects large quantities of material which forms a dusty nebula. The complexity of this nebula has been puzzling astronomers for decades. It has been formed as a result of stellar wind, but it is not understood well why it is so far from having a spherical shape. Neither is known what physical process blows the wind, i.e. what lifts the material up from the stellar surface and makes it expand. “The fate of VY CMa is to explode as a supernova, but it is not known exactly when it will happen”, adds Karl Menten, head of the “Millimeter and Submillimeter Astronomy” Department at MPIfR.

Full Story: http://www3.mpifr-bonn.mpg.de/public/pr/pr-tio-mar2013-en.html

Hubble Observes The Hidden Depths Of Messier 77


Image credit: NASA, ESA & A. van der Hoeven

Image credit: NASA, ESA & A. van der Hoeven

Messier 77 is a galaxy in the constellation of Cetus, some 45 million light-years away from us. Also known as NGC 1068, it is one of the most famous and well-studied galaxies. It is a real star among galaxies, with more papers written about it than many other galaxies put together!

Despite its current fame and striking swirling appearance, the galaxy has been a victim of mistaken identity a couple of times; when it was initially discovered in 1780, the distinction between gas clouds and galaxies was not known, causing finder Pierre Méchain to miss its true nature and label it as a nebula. It was misclassified again when it was subsequently listed in the Messier Catalogue as a star cluster.

Now, however, it is firmly categorised as a barred spiral galaxy, with loosely wound arms and a relatively small central bulge. It is the closest and brightest example of a particular class of galaxies known as Seyfert galaxies — galaxies that are full of hot, highly ionised gas that glows brightly, emitting intense radiation.

Full Story and Image: http://www.spacetelescope.org/news/heic1305/