Observations made by NASA's airborne Stratospheric Observatory for Infrared Astronomy (SOFIA) have led to a development in our understanding of the formation of massive stars. By studying the star G35, the team found that the formation process was more akin to that of smaller stars than was previously thought.
The protostar G35.20-0.74, more commonly known simply as G35, is still in the early stages of its development, and is enclosed within a cocoon of dust and gas. The youth of the star makes it an ideal candidate for the study of massive star formation, but the strength of the infrared light coming from it makes it difficult for infrared space telescopes to obtain detailed images. It's placement within the natal cloud also makes observation using ground-based optical telescopes problematic.
The team overcame these problems by using SOFIA, a Boeing 747SP modified to carry telescopes with an effective diameter of 100 inches (2.5 meters), up to an altitude of 45,000 feet (13,700 meters). The Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) was used to collect infrared readings from the dust covered star.
G35 protostar at wavelengths of 31 and 37 microns taken by the FORCAST instrument on the SOFIA in 2011
G35 resides just 8,000 light-years from Earth, and, at some 20 times the size of our sun, it's one of the largest known protostars. When the researchers used SOFIA to collect the data, they expected to observe a complex formation process driven by the turbulent environment in the center of the new star cluster in which G35 resides. What they actually found was that the giant star is forming by the same simple and symmetrical collapse of interstellar clouds as smaller stars, such as our own sun.
James De Buizer, a SOFIA staff scientist with the Universities Space Research Association, commented on the significance of the findings, said that “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.”