A NASA telescope mounted on a modified Boeing 747SP jet has captured the formation of new stars in a nearby nebula, giving groundbreaking insight into starbirth.
The Rho Ophiuchi cloud complex [Image by NASA/JPL-Caltech/Harvard-Smithsonian CFA]
Rho Ophiuchi is known to be one of the nearest star-forming regions to the solar system. The region is about 407 light years away from Earth, sitting near the Scorpius and Ophiuchus constellations. Though that distance seems quite far away, Rho Ophiuchi is actually relatively close by. The region has a large main cloud full of molecular hydrogen, a key component in the formation of new stars. Stars in the region have an average age of 300,000 years old, much younger than the oldest stars, which are thought to be over 12 billion years old.
There’s a lot that we still don’t know about the more nuanced aspects of starbirth. However, these new observations of the birth of new stars may tell us more about this dazzling phenomenon.
The formation of stars and planets from clouds of dust and gas [Image by Bill Saxton, NRAO/AUI/NSF]
The High-resolution Airborne Wideband Camera-Plus (HAWC+) was mounted on the Stratospheric Observatory for Infrared Astronomy (SOFIA) observatory last year. HAWC+ mainly senses infrared light and shows how light is affected by magnetic fields (the polarization of light). Because of these abilities, HAWC+ allows researchers to see material with lower temperatures, like stellar dust in nebulae.
Astronomers focused the telescope on the star-forming region for their study, which was presented at the 231st American Astronomical Society meeting. This study sought to understand the finer details of starbirth, finding that it’s a more complicated process than scientists thought. The basic idea is this: molecular clouds have mass, and therefore they have gravity—gravity under which the clouds should contract. As the clouds grow denser and denser, they break down into clumps and form dense structures called cores. Newborn stars can be found within these dense cores of gas and dust.
However, that’s not the end of it. "It's a very complicated process," says Fabio Pereira Santos, one of the researchers. Santos and his colleagues focused on Rho Ophiuchi A, an area forming hundreds of new stars that will eventually mature to be much like our sun and have their own planetary systems. Using HAWC+, the researchers were also able to examine dust clump particles and their magnetic alignment.
The central parts of Rho Ophiuchi. Image to the left shows several young stars in formation. [Image by NASA/F. Pereira Santos]
"You can think of the magnetic field as this net of lines that is mixed together with the material in the cloud,” Santos explains. “Whenever the cloud contracts, it brings the field lines together. So, it acts as a kind of tension that holds the material together.
"There is an idea that if you have very strong magnetic fields in some parts of the galaxy, you could run into a situation where gravity will not be able to overcome this magnetic tension. So you won't be able to form any stars... the magnetic field lines don't let the material collapse." However, it then follows that weaker magnetic fields should yield to gravity and thus allow the formation of stars.
The researchers also discovered that magnetic fields may be able to influence how large these newborn stars will be, and whether or not planets will form around them.
Get weekly science updates in your inbox!