The iconic Very Large Array is almost as much pop culture as science instrument. It’s been part of movie plots, on album covers, in comic books and video games. But now, the VLA is being transformed from its original 1970s-vintage technology with state-of-the-art equipment. The National Radio Astronomy Observatory says that the upgrades will increase the VLA’s technical capabilities by factors of as much as 8,000 and greatly increasing the array’s scientific impact.
And so to befit the VLA’s new capabilities, NRAO has decided the array should have a new name. And they are looking for some help from the public.
There is a special website, namethearray.org, where you can submit a name suggestion. You may enter a free-form name, or a word or phrase to come as a prefix before “Very Large Array,” or both.
Entries will be accepted until 23:59 EST on December 1, 2011, and the new name will be announced at NRAO’s Town Hall at the American Astronomical Society’s meeting in Austin, Texas, on Tuesday, January 10, 2012.
“The VLA Expansion Project, begun in 2000, has increased the VLA’s technical capabilities by factors of as much as 8,000, and the new system allows scientists to do things they never could do before,” said Fred K.Y. Lo, Director of the National Radio Astronomy Observatory. “After more than three decades on the frontiers of science, the VLA now is poised for a new era as one of the world’s premier tools for meeting the challenges of 21st-Century astrophysics.”
How do massive stars form? This has been one of the more hotly debated questions in astronomy. Do big stars form by accretion like low-mass stars or do they form through the merging of low mass protostars? Since massive stars tend to be quite far away and usually are surrounded by a shroud of dust, they are difficult to observe, said Stefan Kraus from the University of Michigan. But Kraus and his team have obtained the first image of a dusty disc closely encircling a massive baby star, providing direct evidence that, big or small, all stars form the same way.
“Our observations show a disc surrounding an embryonic young, massive star, which is now fully formed,” said Kraus. “It’s the first time something like this has been observed, and the disk very much resembles what we see around young stars that are much smaller, except everything is scaled up and more massive.”
Not only that, but Kraus and his team found hints at a potential planet-forming region around the nascent star.
Using ESO’s Very Large Telescope Interferometer Kraus and his team focused on IRAS 13481-6124, a star located about 10,000 light-years away in the constellation Centaurus, and about 20 times more massive than our sun. “We were able to get a very sharp view into the innermost regions around this star by combining the light of separate telescopes,” Kraus said, “basically mimicking the resolving power of a telescope with an incredible 85-meter (280-foot) mirror.”
Kraus added that the resulting resolution is about 2.4 milliarcseconds, which is equivalent to picking out the head of a screw on the International Space Station from Earth, or more than ten times the resolution possible with current visible-light telescopes in space.
They also made complementary observations with the 3.58-meter New Technology Telescope at La Silla. The team chose this region by looking at archived images from the Spitzer Space Telescope as well as from observations done with the APEX 12-meter submillimeter telescope, where they discovered the presence of a jet.
“Such jets are commonly observed around young low-mass stars and generally indicate the presence of a disc,” says Kraus.
From their observations, the team believes the system is about 60,000 years old, and that the star has reached its final mass. Because of the intense light of the star — 30,000 times more luminous than our Sun — the disc will soon start to evaporate. The disc extends to about 130 times the Earth–Sun distance — or 130 astronomical units (AU) — and has a mass similar to that of the star, roughly twenty times the Sun. In addition, the inner parts of the disc are shown to be devoid of dust, which could mean that planets are forming around the star.
“In the future, we might be able to see gaps in this and other dust disks created by orbiting planets, although it is unlikely that such bodies could survive for long,” Kraus said. “A planet around such a massive star would be destroyed by the strong stellar winds and intense radiation as soon as the protective disk material is gone, which leaves little chance for the development of solar systems like our own.”
Kraus looks forward to observations with the Atacama Large Millimeter/submillimeter Array (ALMA), currently under construction in Chile, which may be able to resolve the disks to an even sharper resolution.
Previously, Spitzer detected dusty disks of planetary debris around more mature massive stars, which supports the idea that planets may form even in these extreme environments. (Read about that research here.) .