Imaging a multiple star

Apr 18, 2011
An optical image of the field of stars with the triple system GW Orionis at the center. Astronomers have succeeded in obtaining the first very high resolution images of this system in which two stars orbit at a separation of 1.4 AU and the third is at a distance of 8 AU.

(PhysOrg.com) -- Multiple stars - binaries, triplets, or perhaps more stars, that orbit each other - are unique laboratories into the interactions between stars and their early environments.

Young stars develop by accreting matter. How and when the accretion stops, and hence what determines a star's final mass, is among the important unsolved puzzles in astronomy. In a multiple the accretion is even more complex because it potentially involves material around each star in addition to material around the group. A better understanding of multiple stars, especially those that orbit each other closely and hence affect the accretion more strongly, can shed light on the accretion process.

CfA astronomers Nat Carleton and Marc Lacasse, together with a team of eighteen others, used the Smithsonian's Infrared Optical Telescope Array (IOTA, now retired from operation) on Mt. Hopkins, AZ, to make the first direct optical image of a triple with an orbit as small as one (one AU is the average distance of the Earth from the sun).

The astronomers were able to measure reliably the parameters of the triple system, called GW Orionis. One star has a mass of 3.6 solar-masses, and it orbits with a 3.1 solar-mass star at a distance of 1.35 AU. A third , previously inferred to exist from studies of the stellar wobble, is also imaged, and orbits the others at a distance of about 8 AU. The system is unusually bright in the near-infrared, suggesting that some accretion onto the system is still continuing, but further work is needed to sort out the answer to this question. The results highlight the power of optical telescope arrays in the investigation of close multiple stars.

Explore further: New space telescope concept could image objects at far higher resolution than Hubble

Related Stories

Symbiotic Stars

Feb 22, 2010

(PhysOrg.com) -- Many, perhaps even most stars, are members of binaries -- two stars that orbit each other. Symbiotic stars are a small subset of binaries with an attitude: they display characteristic, dramatic, ...

There's More to the North Star Than Meets the Eye

Jan 09, 2006

We tend to think of the North Star, Polaris, as a steady, solitary point of light that guided sailors in ages past. But there is more to the North Star than meets the eye - two faint stellar companions. The ...

Simulating the Birth of Massive Stars

Mar 09, 2010

(PhysOrg.com) -- Astronomers have made great strides recently in understanding how modest stars - those like the sun or smaller -- are formed.

Recommended for you

Black hole chokes on a swallowed star

8 hours ago

A five-year analysis of an event captured by a tiny telescope at McDonald Observatory and followed up by telescopes on the ground and in space has led astronomers to believe they witnessed a giant black hole ...

Swarm of microprobes to head for Jupiter

14 hours ago

A swarm of tiny probes each with a different sensor could be fired into the clouds of Jupiter and grab data as they fall before burning up in the gas giant planet's atmosphere. The probes would last an estimated ...

A recoiling, supermassive black hole

18 hours ago

When galaxies collide, the central supermassive black holes that reside at their cores will end up orbiting one another in a binary pair, at least according to current simulations. Einstein's general theory ...

Chandra celebrates the International Year of Light

Jan 23, 2015

The year of 2015 has been declared the International Year of Light (IYL) by the United Nations. Organizations, institutions, and individuals involved in the science and applications of light will be joining ...

Why is Andromeda coming toward us?

Jan 23, 2015

I don't want to alarm you, but there's a massive galaxy heading our way and will collide with us in a few billion years. But aren't most galaxies speeding away? Why is Andromeda on a collision course with ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Nik_2213
not rated yet Apr 18, 2011
A couple of arrows to disambiguate that star-field would be nice...
Still, resolving 1AU at that distance is astonishing !! "GW Orionis is a single-line spectroscopic binary Classical T Tauri Star with an orbital period of 242 days located at 400 pc (Mathieu et al)"
d_robison
not rated yet Apr 18, 2011
A couple of arrows to disambiguate that star-field would be nice...
Still, resolving 1AU at that distance is astonishing !! "GW Orionis is a single-line spectroscopic binary Classical T Tauri Star with an orbital period of 242 days located at 400 pc (Mathieu et al)"


I agree, ~1 AU at this distance is an amazing feat for optical telescopes.

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.