New satellite data like an ultrasound for baby stars

A composite image detailing the pre-life story of a star like the Sun, spanning about 10 million years from conception to birth.

A composite image detailing the pre-life story of a star like the Sun, spanning about 10 million years from conception to birth.

An international team of researchers have been monitoring the “heartbeats” of baby stars to test theories of how the Sun was born 4.5 billion years ago.

In a paper published in Science magazine today, the team of 20 scientists describes how data from two space telescopes – the Canadian Space Agency’s MOST satellite and the French CoRoT mission – have unveiled the internal structures and ages of young stars before they’ve even emerged as full-fledged stars.

“Think of it as ultrasound of stellar embryos,” explains UBC Professor Jaymie Matthews, MOST Mission Scientist and a co-author of the study. “Stars can vibrate due to sound waves bouncing inside. We detect the sound vibrations across the vacuum of space by the subtle changes in stellar brightness. Then we translate the frequencies of those vibrations into models of the structures of those stars’ hidden interiors.”

Dr. Konstanze Zwintz, from the KU Leuven Institute of Astronomy in Belgium and lead author of the study, calls this technique of probing protostars with sound waves “echography.” Astronomers are using measurements of this ‘heartbeat’ as a virtual time machine to explore the life stages of a star.

The study found that when an emerging star is closer to the initial stage of its formation (as in the first trimester of a human pregnancy), it pulsates slowly. When it gets closer to igniting thermonuclear fusion in its core to become a true star (like the moment of human birth), it pulsates ever faster. And when the hydrogen fuel at the core of a star is exhausted, it enters the last stages of its life.

Watching soon-to-be-stars in young clusters like NGC 2264, the focus of the study, is like watching our Sun during its birth, says Matthews.

MOST (Microvariability & Oscillations of STars) is a Canadian Space Agency (CSA) mission launched in 2003 to perform asteroseismology and study planets beyond the Solar System. The telescope was designed and largely built at UBC and is operated there under the supervision of Prof. Matthews.

Read more at news.ubc.ca and www.sciencemag.org
See also: How Do You Age a Star? Check Its ‘Heartbeat’ (Video)

New Planets Feature Young Star and Twin Neptunes

Illustration of a system with twin Neptune-like planets


An international team, including Oxford University scientists, has discovered 10 new planets. Amongst them is one orbiting a star perhaps only a few tens of million years old, twin Neptune-sized planets, and a rare Saturn-like world.
The planets were detected using the CoRoT (Convection, Rotation and Transits) space telescope, operated by the French space agency CNES. It discovers planets outside our solar system — exoplanets — when they ‘transit’, that is pass in front of their stars.
The new finds were announced on 14 June at the Second CoRoT Symposium, held in Marseille…. Continue reading New Planets Feature Young Star and Twin Neptunes

Corot telescope in exoplanet haul

Corot and other telescopes measure the light change when a planet "transits"

Ten new planets outside our Solar System have been spotted by the French-led Corot satellite, bringing the total number of known exoplanets to 561.

They include one planet orbiting an unusually young star, and two Neptune-sized planets orbiting the same star.
Corot, launched in 2006, spots planets by measuring the tiny dip in stellar light that occurs when planets pass between the stars and the Earth.
It has now added 23 planetary systems to the ever-growing roster.
Corot, operated by France’s space agency CNES, was launched in late 2006. It went into orbit shortly before Kepler, a similar mission by the American space agency Nasa.
Originally scheduled to run only until mid-2008, its remit has since been extended to 2013.
It has since established itself not only as a planet-hunter but also a precise instrument for astroseismology – the study of the composition of stars based on the light they emit.
In the latest list of 10 exoplanet finds, seven are so-called “hot Jupiters”, gas giant planets similar to our own Jupiter but far closer to their host star – completing their orbits in just days.
Two more orbit the star Corot-24, with diameters equal to and about 1.4 times that of Neptune, completing their orbits in five and 12 days, respectively.
One of the hot Jupiter planets orbits the star Corot-18, which is believed to be just 600 million years old. This is of particular interest to astrophysicists because there is much to be learned from the earliest stages of planet formation.
“If we want to understand the conditions in which planets form, we need to catch them within the first few hundred million years,” said Suzanne Aigrain, a University of Oxford astrophysicist who is part of the Corot team.
“In the case of Corot-18, different ways of determining the age give different results, but it’s possible that the star might be only a few tens of millions of years old. If this is confirmed, then we could learn a lot about the formation and early evolution of hot gas giant planets by comparing the size of Corot-18b to the predictions of theoretical models.”

  • 1. 4-colour CCD camera and electronics: Captures and analyses starlight
  • 2. Baffle: Works to shield the telescope from extraneous light
  • 3. Telescope: A 30cm mirror; it views the star fields
  • 4. Proteus platform: Contains communication equipment, temperature controls and direction controls
  • 5. Solar panel: Uses the Sun’s radiation to power the satellite

http://www.bbc.co.uk/news/science-environment-13761405