First Baby Photo of Stellar Twins

Sep 21, 2005
First Baby Photo of Stellar Twins

Newborn stars are difficult to photograph. They tend to hide in the nebulous stellar nurseries where they formed, enshrouded by thick layers of dust. Now, Smithsonian astronomer T.K. Sridharan (Harvard-Smithsonian Center for Astrophysics) and his colleagues have photographed a pair of stellar twins in infrared light, which penetrates the dust. And these babies are whoppers, weighing several times the mass of the Sun.

Image: Detailed infrared observations from the UKIRT telescope revealed a massive binary star system recently formed in the constellation Cygnus. In this pseudo-color image, longer-wavelength infrared light is represented as red while shorter-wavelength infrared is represented as blue. The pink spot at the center of the image is the higher-mass primary star. To its lower right, a green spot marks the location of a less massive companion star seen here for the first time. The bright blue-white spots at left and upper right are cavities cleared in the surrounding circumstellar disk by an outflow from the newborn star system. The stars are seen along the plane of the edge-on disk, between the blue patches. The presence of a disk suggests that massive, multiple-star systems form the same way as the Sun, by gradually accreting material from a gaseous disk. Credit: T.K. Sridharan (CfA), S.J. Williams & G.A Fuller (UMIST)

Moreover, Sridharan's images reveal a circumstellar disk surrounding the more massive of the two stars. The presence of a disk suggests that massive, multiple-star systems form the same way as the Sun, by gradually accreting material from a gaseous disk.

"This system is the youngest massive binary ever to be directly imaged - only about 100,000 years old," said Sridharan.

Sridharan and his colleagues studied an object known as IRAS 20126+4104, located more than 5,000 light-years away in the constellation Cygnus the Swan. IRAS 20126+4104 was suspected of harboring a binary star because outflows from the region wobbled back and forth like a spinning top. The wobble hinted at the gravitational tug of an unseen companion.

On several exceptionally clear and steady nights, the researchers were able to take highly detailed infrared images of this object using the UKIRT telescope on Mauna Kea, Hawaii. Those images revealed not one but two stars, as well as a dark dust lane where the inner parts of the disk, known from previous radio-wavelength observations, appeared nearly edge-on in silhouette.

"Many people have seen the iconic Hubble Space Telescope images of circumstellar disks around low-mass stars. This image is the equivalent for high-mass stars," said Sridharan.

Between them the two stars weigh more than 10 times the mass of the Sun. Sridharan calculates that the surrounding disk contains at least one-tenth of a solar mass, which is enough material to make 100 Jupiter-sized worlds. The disk may be even more massive. It extends outward for at least 850 astronomical units, or 80 billion miles (more than 20 times the distance to Pluto). Interestingly, the smaller companion star currently is located at the same distance from the primary star, hinting that the companion's gravity may play a role in limiting the outer reaches of the disk.

Sridharan said that the next step in studying this intriguing twin system is to get higher-resolution observations using adaptive optics or interferometry. Such data will yield a better estimate of the companion's mass and a detailed profile of the disk.

"We are currently following several leads to investigate this star system, so stay tuned," Sridharan added.

Sridharan's co-authors are S.J. Williams and G.A. Fuller of UMIST (Manchester, UK). This research was published in the Sept. 20, 2005, issue of The Astrophysical Journal Letters and is available online at arxiv.org/abs/astro-ph/0508342 .

Source: Harvard-Smithsonian Center for Astrophysics

Explore further: US-India to collaborate on Mars exploration

add to favorites email to friend print save as pdf

Related Stories

How to Build A Big Star

Sep 06, 2005

The most massive stars in our galaxy weigh as much as 100 small stars like the Sun. How do such monsters form? Do they grow rapidly by swallowing smaller protostars within crowded star-forming regions?

Recommended for you

Image: The Pillars of Creation

2 minutes ago

The Pillars of Creation (seen above) is an image of a portion of the Eagle nebula (M16) taken by Hubble Space Telescope in 1995. It soon became one of the most iconic space images of all time. The Eagle nebula ...

Student to live in simulated space habitat

29 minutes ago

A Purdue University industrial engineering doctoral student is among six "crew members" spending the next eight months in a domed habitat on a volcanic landscape mimicking life on a Martian outpost.

The wake-up call that sent hearts racing

3 hours ago

"But as the minutes ticked by, the relaxed attitude of many of us began to dissolve into apprehension. Our levels of adrenaline and worry began to rise."

US-India to collaborate on Mars exploration

12 hours ago

The United States and India, fresh from sending their own respective spacecraft into Mars' orbit earlier this month, on Tuesday agreed to cooperate on future exploration of the Red Planet.

Swift mission observes mega flares from a mini star

12 hours ago

On April 23, NASA's Swift satellite detected the strongest, hottest, and longest-lasting sequence of stellar flares ever seen from a nearby red dwarf star. The initial blast from this record-setting series ...

Sandblasting winds shift Mars' landscape

17 hours ago

High winds are a near-daily force on the surface of Mars, carving out a landscape of shifting dunes and posing a challenge to exploration, scientists said Tuesday.

User comments : 0