Protostar growth spurts

November 4, 2015, National Radio Astronomy Observatory
Astronomers using ALMA have imaged the episodic outflow of a young protostar known as CARMA-7. The twin jets -- each nearly 2.46 trillion kilometers long -- have distinct gaps, revealing that the star is growing by fits-and-starts. Credit: Saxton (NRAO/AUI/NSF); A. Plunkett et al.; ALMA (NRAO/ESO/NAOJ)

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered an adolescent protostar that is undergoing a rapid-fire succession of growth spurts. Evidence for this fitful youth is seen in a pair of intermittent jets streaming away from the star's poles.

Known as CARMA-7, the is one of dozens of similar objects in the Serpens South star cluster, which is located approximately 1,400 light-years from . This clutch of nascent stellar objects was first detected by and named for the Combined Array for Research in Millimeter-wave Astronomy (CARMA) telescope.

"This young protostar is undergoing periods of rapid growth separated by periods of relative calm," said Adele Plunkett, previously a National Science Foundation (NSF) graduate research fellow at Yale University and now a fellow at the European Southern Observatory (ESO) in Chile. "This punctuated stellar formation provides important insights into the chaotic interplay within this tightly packed cluster of young stars."

All stars form in dense clouds of dust and gas. As material condenses and a star begins to evolve, surrounding material forms a flattened, rotating disk that flows onto its surface. Because of the rotational energy of the material in the disk and with the help of the star's magnetic fields, a portion of that material gets ejected from the star's poles, forming a pair of jets that can be seen with radio telescopes like ALMA.

In a recent survey of several protostars in the Serpens South region, astronomers were surprised to find one with brilliantly defined jets that seem to turn on-and-off with startling regularity, alternating from one to the other in possibly as little as 100 years. The protostar and its jets are oriented in such a way that the upper jet is mostly moving away from us and the lower jet is mostly moving toward us.

These prominent jets offer an otherwise hidden insight into the environment of the accretion disk surrounding the protostar. Since the accretion process is obscured by the surrounding dust and gas, the outflow is an important observational proxy. However, since many stars are forming in close proximity, astronomers needed powerful ALMA observations to disentangle the chaotic outflow activity.

The ALMA data reveal that there were 22 distinct ejection events associated with the CARMA-7 protostar. These outflows, which travel up to 2.46 trillion kilometers from the protostar, also are impacting the surrounding cluster and intermingling with other jets.

Previous observations were unable to distinguish the outflow from CARMA-7 from the surrounding outflows driven by neighboring protostars. "These sources are so young and embedded and neither optical nor near-infrared light could give a complete picture of the protostar and its outflow," said Plunkett. "This shows how valuable ALMA is for observing a region like this."

A paper describing these results is published in the journal Nature.

Explore further: A new telescope probes a young protostar

More information: Episodic molecular outflow in the very young protostellar cluster Serpens South, DOI: 10.1038/nature15702

Related Stories

A new telescope probes a young protostar

April 3, 2013

(Phys.org) —IRAS 16293-2922B is a very young star – a protostar - perhaps only about ten thousand years old. Slightly smaller in mass than our Sun, it is still deeply embedded in its surrounding natal material, and apparently ...

Magnetic field around young star captured

October 27, 2014

For the first time astronomers, including SRON astronomer Woojin Kwon, have been able to capture the magnetic field in the accretion disk around a young star. The shape of the field was a big surprise. The discovery suggests ...

Searching for orphan stars amid starbirth fireworks

September 30, 2015

A new Gemini Observatory image reveals the remarkable "fireworks" that accompany the birth of stars. The image captures in unprecedented clarity the fascinating structures of a gas jet complex emanating from a stellar nursery ...

The X-Ray Puzzle of Protostellar Jets

June 22, 2011

(PhysOrg.com) -- A new star develops by accreting material from a circumstellar disk; both in turn are embedded in a much larger, more nearly spherical envelope of in-falling dust and gas. The protostar is obscured in the ...

Recommended for you

Did a rogue star change the makeup of our solar system?

July 20, 2018

A team of researchers from the Max-Planck Institute and Queen's University has used new information to test a theory that suggests a rogue star passed close enough to our solar system millions of years ago to change its configuration. ...

Where to search for signs of life on Titan

July 20, 2018

New findings, published in the journal Astrobiology, suggest that large craters are the prime locations in which to find the building blocks of life on Saturn's largest moon, Titan.

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

wduckss
1 / 5 (2) Nov 05, 2015
"Because of the rotational energy of the material in the disk and with the help of the star's magnetic fields, a portion of that material gets ejected from the star's poles, forming a pair of jets that can be seen"

New evidence that the process is the same for quasars and stars, rapid rotation of the cyclone in the center of the body.

See: Observing the quasars through rotation http://www.svemir...html#14b
viko_mx
1.8 / 5 (5) Nov 05, 2015
Probably only the authors of this article can see the proto star on this picture.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.