People have looked at the stars for thousands of years, but only about 20 years ago did astronomers become interested in the stuff inbetween.
Reversing their focus on the sky, astronomers can see that dark patches in the Milky Way are really giant molecular clouds. These big blobs of gas can be many times the size of the sun. Eventually, these clouds fall in on themselves, the cool gas becomes hot and dense and a star is born.
Reversing their focus on the sky, astronomers can see that dark patches in the Milky Way are really giant molecular clouds. These big blobs of gas can be many times the size of the sun. Eventually, these clouds fall in on themselves, the cool gas becomes hot and dense and a star is born.
“The details are tricky. We still don’t know how it really works,” said a South Pole winter scientist Nicholas Tothill from the Smithsonian Astrophysical Observatory.
This process of how they form could answer a lot of questions about stars themselves: why are they as big and heavy as they are? Why are there more light stars than heavy stars and more red stars than blue stars?
“That is determined by what goes on in the galaxy – by molecular clouds,” Tothill said.
“Stars are fairly well understood,” he said. “But the gas – where they come from and where they go to – we have to understand this stuff.”
At the South Pole a 1.7mm telescope named AST/RO (Antarctic Submillimeter Telescope and Remote Observatory) has been measuring galactic gas clouds since 1995.
Other, similar telescopes operate 16,000 feet high in the Chilean desert and from aircraft and satellite, but the dry air over the South Pole makes the best land-based viewing site in the world.
“In submillimeter astronomy, light gets absorbed by atmospheric water vapor so cold, dry air is very good stuff,” Tothill said.
AST/RO picks up submillimeter-wave radiation emitted by dense gas and dust between the stars.
These areas seem black to the human eye but the gas molecules actually emit a non-visible light. The wavelengths of that light can be picked up by submillimeter telescopes like AST/RO.
Concentrating on the wavelengths given off by highly excited carbon monoxide molecules, AST/RO can locate star-forming cores and study the structure and movement of molecular clouds and how the other elements in the galaxy affect them.
Winter is the prime observation time for AST/RO, when the water vapor concentration is lowest so summers are mostly dedicated to maintenance, repair and development work.
The researchers want to minimize the chance of something going wrong during the isolation of winter.
Last year, a new laser-driven receiver was installed. Tothill said the new receiver would provide a higher, more stable frequency for the telescope.
It is the highest-frequency radio astronomy receiver in the world. The lower frequency receivers, were only a few centimeters in size but a larger and heavier device is needed to operate at frequencies of 1400 gigahertz.
“Basically, we’ve replaced something that weighed a few ounces with something that weighs 3,000 pounds (1,360 kg). The only place we could do that is from the ground.”
The two-meter long receiver, which was fine tuned by technicians over summer, will be mounted to the ceiling in the cramped building 800 meters from the geographic South Pole.
The actual telescope is on the roof of the building. It sends the radiated light to the receiver through a series of mirrors.
The project is headed by Antony Stark of the Smithsonian Astrophysical Observatory. AST/RO works as a consortium, with participants from several universities and accepts research proposals from the wider scientific community.
This process of how they form could answer a lot of questions about stars themselves: why are they as big and heavy as they are? Why are there more light stars than heavy stars and more red stars than blue stars?
“That is determined by what goes on in the galaxy – by molecular clouds,” Tothill said.
“Stars are fairly well understood,” he said. “But the gas – where they come from and where they go to – we have to understand this stuff.”
At the South Pole a 1.7mm telescope named AST/RO (Antarctic Submillimeter Telescope and Remote Observatory) has been measuring galactic gas clouds since 1995.
Other, similar telescopes operate 16,000 feet high in the Chilean desert and from aircraft and satellite, but the dry air over the South Pole makes the best land-based viewing site in the world.
“In submillimeter astronomy, light gets absorbed by atmospheric water vapor so cold, dry air is very good stuff,” Tothill said.
AST/RO picks up submillimeter-wave radiation emitted by dense gas and dust between the stars.
These areas seem black to the human eye but the gas molecules actually emit a non-visible light. The wavelengths of that light can be picked up by submillimeter telescopes like AST/RO.
Concentrating on the wavelengths given off by highly excited carbon monoxide molecules, AST/RO can locate star-forming cores and study the structure and movement of molecular clouds and how the other elements in the galaxy affect them.
Winter is the prime observation time for AST/RO, when the water vapor concentration is lowest so summers are mostly dedicated to maintenance, repair and development work.
The researchers want to minimize the chance of something going wrong during the isolation of winter.
Last year, a new laser-driven receiver was installed. Tothill said the new receiver would provide a higher, more stable frequency for the telescope.
It is the highest-frequency radio astronomy receiver in the world. The lower frequency receivers, were only a few centimeters in size but a larger and heavier device is needed to operate at frequencies of 1400 gigahertz.
“Basically, we’ve replaced something that weighed a few ounces with something that weighs 3,000 pounds (1,360 kg). The only place we could do that is from the ground.”
The two-meter long receiver, which was fine tuned by technicians over summer, will be mounted to the ceiling in the cramped building 800 meters from the geographic South Pole.
The actual telescope is on the roof of the building. It sends the radiated light to the receiver through a series of mirrors.
The project is headed by Antony Stark of the Smithsonian Astrophysical Observatory. AST/RO works as a consortium, with participants from several universities and accepts research proposals from the wider scientific community.
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