April 17, 2013
Airborne Observatory Reveals Mystery Of Star Formation
Brett Smith for redOrbit.com - Your Universe Online
Using observations from an airborne observatory, NASA researchers have discovered new details on how massive stars form within a cloud of interstellar gas and dust.An emerging star known as G35 has been observed forming in an orderly process similar to the one undergone by smaller stars like our sun, according to the scientists´ report in the Astrophysical Journal.
"The focus of our study has been to determine how massive stars actually form," said Zhang, an astronomer with the University of Florida (UFL). "We thought the G35 protostar's structure would be quite complicated, but instead we found it is simple, like the cocoons of protostars with the sun's mass."
Observations of the emerging star were made in 2011 using SOFIA, a modified Boeing 747 that can carry a powerful telescope to altitudes as high as 45,000 feet. SOFIA replaced NASA´s previous flying observatory, the Kuiper Airborne Observatory, in 2010.
According to NASA, G35 was an ideal target for study because it is in the beginning stages of formation. However, because infrared light coming from G35 is so strong, astronomers weren´t able to rely on any number of orbiting observatories for capturing detailed images. The emerging star is also deeply enmeshed in the surrounding cloud of gas and dust that it cannot be accurately imaged from the ground in the visible light spectrum.
In the thin upper reaches of the atmosphere, the NASA team was able to use the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) to distinctly see G35 shrouded inside a dense interstellar dust cloud. FORCAST was able to collect infrared light emitted from the cloud to make out faint details at wavelengths inaccessible to other telescopes on the ground or in space.
"Massive stars, although rare, are important because there is evidence they foster the formation of smaller stars like our sun, and because at the ends of their lives they create and distribute chemical elements that are the basic building blocks of Earth-like planets," co-author James De Buizer, a SOFIA staff scientist at NASA's Ames Research Center in Moffett Field, California, said in a statement.
Using computer modeling, the scientists were able to refine the images taken on board SOFIA, revealing a protostar heating the interstellar cloud and expelling cone-shaped jets of gas.
According to a statement from NASA, the study´s findings reinforce the value of an airborne observatory like SOFIA and give “scientists hope that data gathered in this way substantially will advance their understanding of the Milky Way galaxy.”
The findings also call for a reevaluation of theories surrounding star formation. Stars typically form within dense regions filled by molecular clouds and remnants of former stars. The clouds of stellar material are typically composed of 70 percent hydrogen and the remaining material is mostly helium.
These “stellar nurseries” form stars through the collapse of interstellar plasma into spheres, which then ignite to become stars.
Image Below: NASA's SOFIA flying observatory lifts off from Air Force Plant 42 in Palmdale, Calif., at sunset on July 15, 2011 to begin an all-night astronomical observation mission. The highly modified Boeing 747SP carries a high-tech 100-inch infrared telescope. Credit: NASA / Carla Thomas