Measuring the clumpiness of proto-planetary disks

June 14, 2011
A combined X-ray and optical image of the young stars in the heart of the Orion Nebula. A new infrared study has found that most of the young stars vary in intensity, some apparently due to obscuring clumps of material in a rotating disk. Credit: X-ray: NASA/CXC/Penn State/E.Feigelson & K.Getman et al.; Optical: NASA/ESA/STScI/M. Robbert et al.

(PhysOrg.com) -- The process of star formation, once thought to involve just the simple coalescence of material under the influence of gravity, actually entails a complex series of stages, with the youngest stars assembling circumstellar disks of material (possibly preplanetary in nature) for example. Understanding these early stages has been difficult for astronomers, in part because because they take place in nurseries heavily obscured by dust. Nevertheless, they are critically important to an understanding of how our young solar system and its planets were born and evolved.

The and its IRAC have enabled astronomers during the past few years to discover and study large numbers young stellar objects ("YSOs") in star forming clouds of gas and dust. Its sensitive can penetrate most of the dusty veil and pinpoint the many faint stars, cool and red, that are between about one and ten million years old, or sometimes younger.

In a new study of the time variability of YSOs, CfA astronomers Joe Hora and Jan Forbrich, together with a large team of collaborators, used IRAC to conduct a timed series of observations (81 snapshots over 40 days) of YSOs in the . They discovered that 70% of the YSOs thought to have disks around them vary in time, with variations that fall roughly into four categories: periodic, flaring, irregular, and narrow flux dips.

These latter cases, called "dippers," are suspected of being caused by clumps of dust in the circumstellar disk that happen to pass across the line-of-sight to the star as the disk rotates; they may also be due to a warp in the rotating disk that crosses the line-of-sight. With additional observations, including some from ground-based telescopes, the scientists plan to confirm and model the nature of these clumps, as well as to explain more specifically each of the other types of variability on a case-by-case basis.

Explore further: Hubble Reveals Two Dust Disks Around Nearby Star

Related Stories

Hubble Reveals Two Dust Disks Around Nearby Star

June 27, 2006

NASA's Hubble Space Telescope has revealed two dust disks circling the nearby star Beta Pictoris. The images confirm a decade of scientific speculation that a warp in the young star's dust disk may actually be a second inclined ...

Spitzer Reveals New Wonders in the Familiar Orion Nebula

August 15, 2006

The Orion nebula is one of the most famous and easily viewed deep-sky sights. Located in the sword of Orion the Hunter, this distant cloud of gas and dust holds hundreds of young stars. At its center, a cluster of four bright, ...

Making Jupiters

August 21, 2009

IC348 is a glowing nebula of young stars, hot gas, and cold dust seen in the direction of the constellation of Perseus. It is the nearest rich cluster of young stars to earth, being only about one thousand light-years away. ...

Colony of Young Stars Shines in New Spitzer Image

April 1, 2010

(PhysOrg.com) -- Astronomers have their eyes on a hot group of young stars, watching their every move like the paparazzi. A new infrared image from NASA's Spitzer Space Telescope shows the bustling star-making colony of the ...

Recommended for you

Exoplanets 20/20: Looking back to the future

July 31, 2015

Geoff Marcy remembers the hair standing up on the back of his neck. Paul Butler remembers being dead tired. The two men had just made history: the first confirmation of a planet orbiting another star.

Image: Hubble sees a dying star's final moments

July 31, 2015

A dying star's final moments are captured in this image from the NASA/ESA Hubble Space Telescope. The death throes of this star may only last mere moments on a cosmological timescale, but this star's demise is still quite ...

Earth flyby of 'space peanut' captured in new video

July 31, 2015

NASA scientists have used two giant, Earth-based radio telescopes to bounce radar signals off a passing asteroid and produce images of the peanut-shaped body as it approached close to Earth this past weekend.

Binary star system precisely timed with pulsar's gamma-rays

July 31, 2015

Pulsars are rapidly rotating compact remnants born in the explosions of massive stars. They can be observed through their lighthouse-like beams of radio waves and gamma-rays. Scientists at the Max Planck Institute for Gravitational ...

0 comments

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.