Two Telescopes Combine to Probe Young 'Family' of Stars

Aug 08, 2007
Two Telescopes Combine to Probe Young 'Family' of Stars
This Spitzer Space Telescope photograph shows the Serpens South star cluster – a relatively dense group of 50 young stars, 35 of which are protostars just beginning to form. Tints of green in the image represent hot hydrogen gas excited when high-speed jets of gas ejected by infant stars collide with the cool gas in the surrounding cloud. Wisps of red in the background are organic molecules called polycyclic aromatic hydrocarbons (PAHs). Credit: NASA/JPL-Caltech/L. Allen (Harvard-Smithsonian CfA) & Gould's Belt Legacy Team

A spectacular new image from NASA's Spitzer Space Telescope uncovers a small group of young stellar "siblings" in the southern portion of the Serpens cloud – located approximately 848 light-years away from Earth. Scientists suspect that this discovery will lead them to more clues about how these cosmic families, which contain hundreds of gravitationally bound stars, form and interact.

"It's amazing how these stars really stand out in the Spitzer images. At visible wavelengths the stars can't be seen at all; they are completely obscured by the dust in the cloud," says Robert Gutermuth, of the Harvard-Smithsonian Center for Astrophysics. "This is the first time that anyone has ever seen these stars."

Astronomers dubbed the newfound cluster “Serpens South” for its location on the sky.

Spitzer uncovered the young star cluster, but couldn’t determine whether they are forming a new "family unit," or are members of an established stellar "clan." In the case of Serpens South, Dr. Tyler Bourke, also of the Harvard-Smithsonian Center for Astrophysics, used the Smithsonian’s Submillimeter Array (SMA) to solve this mystery of stellar ancestry.

From the ground, he measured motions of the gas surrounding the newly formed cluster, and determined that the newly discovered stars belonged to the Serpens star-forming cloud, which also hosts the famous and massive Serpens star cluster.

“With the SMA, we were able to show that Serpens South is moving at the same speed as the Serpens Cluster,” said Bourke. “It looks like the smaller families are sticking together.”

Spitzer’s Family Portrait

In the Spitzer photograph, the newly discovered Serpens South stars are shown as green, yellow, and orange specks, sitting atop a black line that runs through the middle of the image. The "line" is a long, dense patch of cosmic dust and gas, which is currently condensing to form stars. Like raindrops, stars form when thick cosmic clouds collapse.

Tints of green represent hot hydrogen gas. Spitzer can see this hydrogen gas "fingerprint" when the high-speed jets shooting out of the young stars violently collide with cool gas in the surrounding cloud.

Wisps of red in the background are organic molecules called polycyclic aromatic hydrocarbons (PAHs) that are being excited by stellar radiation from a neighboring star-forming region called W40. On Earth, PAHs are found on charred barbeque grills and in sooty automobile exhaust.

"This image provides just a taste of the exciting science that will come from the Gould's Belt Legacy project," says Lori Allen of the Harvard-Smithsonian Center for Astrophysics, principal investigator of the Gould’s Belt Legacy program, which discovered the Serpens South Cluster.

The Gould’s Belt Survey will study all prominent star-forming regions within about 1,600 light-years of Earth. Taken together, these regions comprise a ring of molecular clouds and associated young stars known as the Gould’s Belt. Data from Spitzer will be combined with observations from the James Clerk Maxwell telescope and the Herschel Space Observatory to better characterize Gould’s Belt, which was first described by astronomer Benjamin Gould in 1879.

Cluster Beginnings

For years, astronomers have debated how members of large stellar families, which can contain hundreds of stars, are related. Some astronomers suspect that the stars may be "fraternal siblings" – born at the same time from the same "parent" cloud of gas and dust. Meanwhile, other scientists suspect that these stellar family members are "adopted" – meaning the stars are born in small batches of a few at a time, and eventually many of these small stellar groups will "bond" to form a massive star cluster, or family.

According to Allen, one of the greatest challenges in determining how a cluster's stars are related is finding the smaller, younger star clusters in the first place.

"Spitzer is currently the only telescope with the capabilities to find young star clusters like Serpens South, which are deeply embedded inside giant cosmic clouds of gas and dust," says Allen.

The Gould’s Belt Legacy project will examine the evidence for “fraternal” versus “adopted” star families in detail for a well-defined region of space. The answers thereby generated will lead to a greater understanding of how stars, including our Sun, form. The project’s CfA team members include Allen, Tracy Huard, Dawn Peterson and Phil Myers.

Source: Harvard-Smithsonian Center for Astrophysics

Explore further: Exomoons Could Be Abundant Sources Of Habitability

add to favorites email to friend print save as pdf

Related Stories

The 'Serpent' star-forming cloud hatches new stars

May 30, 2014

( —Stars that are just beginning to coalesce out of cool swaths of dust and gas are showcased in this image from NASA's Spitzer Space Telescope and the Two Micron All Sky Survey (2MASS). Infrared ...

'Heaven and hell' in the serpent's tail

Nov 21, 2013

Renowned University of Arizona astrophotographer and astronomy educator Adam Block has taken this photograph of glowing, colorful beauty shimmering behind a dark cloud of dust and gas in the constellation ...

A cluster within a cluster

Apr 25, 2012

( -- The star cluster NGC 6604 is shown in this new image taken by the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. It is often overlooked in ...

Eagle Nebula: A new view of an icon

Jan 17, 2012

( -- The Eagle Nebula as never seen before. In 1995, the Hubble Space Telescope's 'Pillars of Creation' image of the Eagle Nebula became one of the most iconic images of the 20th century. Now, ...

First temperate exoplanet sized up (w/ Video)

Mar 17, 2010

( -- Combining observations from the CoRoT satellite and the ESO HARPS instrument, astronomers have discovered the first “normal” exoplanet that can be studied in great detail. Designated Corot-9b, ...

An Eagle of Cosmic Proportions

Jul 16, 2009

( -- Today ESO has released a new and stunning image of the sky around the Eagle Nebula, a stellar nursery where infant star clusters carve out monster columns of dust and gas.

Recommended for you

New radio telescope ready to probe

1 hour ago

Whirring back and forth on a turning turret, the white, 40-foot dish evokes the aura of movies such as "Golden Eye" or "Contact," but the University of Arizona team of scientists and engineers that commissioned ...

Exomoons Could Be Abundant Sources Of Habitability

Oct 20, 2014

With about 4,000 planet candidates from the Kepler Space Telescope data to analyze so far, astronomers are busy trying to figure out questions about habitability. What size planet could host life? How far ...

Partial solar eclipse over the U.S. on Thursday, Oct. 23

Oct 17, 2014

People in most of the continental United States will be in the shadow of the Moon on Thursday afternoon, Oct. 23, as a partial solar eclipse sweeps across the Earth. For people looking through sun-safe filters, from Los Angeles, ...

A newborn supernova every night

Oct 17, 2014

Thanks to a $9 million grant from the National Science Foundation and matching funds from the Zwicky Transient Facility (ZTF) collaboration, a new camera is being built at Caltech's Palomar Observatory that ...

User comments : 0