Featured Research

from universities, journals, and other organizations

Pulsating star sheds light on exoplanet

Date:
July 29, 2013
Source:
New York University
Summary:
Astronomers have devised a way to measure the internal properties of stars —- a method that offers more accurate assessments of their orbiting planets.

A team of researchers has devised a way to measure the internal properties of stars -- a method that offers more accurate assessments of their orbiting planets. The researchers examined HD 52265 and a single planet in the star's orbit. This is an artistic rendering of HD 52265 and its orbiting Jupiter-like planet.
Credit: Image courtesy of MPI for Solar System Research/Mark A. Garlick

A team of researchers has devised a way to measure the internal properties of stars -- a method that offers more accurate assessments of their orbiting planets.

The research, which appears in Proceedings of the National Academy of Sciences, was conducted by a multi-national team of scientists, including physicists at New York University, Princeton University, and the Max Planck Institute for Solar System Research.

The researchers examined HD 52265 -- a star approximately 92 light years away and nearly 20 percent more massive than our Sun. More than a decade ago, scientists identified an exopanet -- a planet outside our Solar System -- in the star's orbit. HD 52265, then, served as an ideal model for both measuring stars' properties and how such properties can shed light on planetary systems.

Previously, scientists inferred stars' properties, such as radius, mass, and age, by considering observations of their brightness and color. Often these stars' properties were not known to sufficient accuracy to further characterize the nearby planets.

In the PNAS study, the scientists adopted a new approach to characterize star-planet systems: asteroseismology, which identifies the internal properties of stars by measuring their surface oscillations. Some have compared this approach to seismologists' use of earthquake oscillations to examine Earth's interior.

Here, they were able to make several assessments of the star's traits, including its mass, radius, age, and -- for the first time -- internal rotation. They used the COROT space telescope, part of a space mission led by the French Space Agency (CNES) in conjunction with the European Space Agency (ESA), to detect tiny fluctuations in the intensity of starlight caused by starquakes. The researchers confirmed the validity of the seismic results by comparing them with independent measurements of related phenomena. These included the motion of dark spots on the star's surface and the star's spectroscopic rotational velocity.

Unlike other methods, the technique of asteroseismology returns both the rotation period of the star and the inclination of the rotation axis to the line of sight.

The scientists could then use these findings to make a more definitive determination of an orbiting exoplanet. While it had previously been identified as an exoplanet by other scientists, some raised doubts about this conclusion, positing that it could actually be a brown dwarf -- an object too small to be a star and too large to be a planet.

But, armed with the precise calculations yielded by asteroseismology, the researchers on the PNAS study were able to enhance the certainty of the earlier conclusion. Specifically, given the inclination of the rotation axis of HD 52265 and the minimum mass of the nearby exoplanet, the researchers could infer the true mass of the latter -- which was calculated to be roughly twice that of our planet Jupiter and therefore too small to be a brown dwarf.

The study's authors included: Katepalli Sreenivasan, president of Polytechnic Institute of NYU and dean of engineering at NYU; Shravan Hanasoge, an associate research scholar in geosciences at Princeton University and a visiting scholar at NYU's Courant Institute of Mathematical Sciences; and Laurent Gizon, director of the Max Planck Institute for Solar System Research and a professor at the University of Goettingen in Germany.


Story Source:

The above story is based on materials provided by New York University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Laurent Gizon, Jérome Ballot, Eric Michel, Thorsten Stahn, Gérard Vauclair, Hans Bruntt, Pierre-Olivier Quirion, Othman Benomar, Sylvie Vauclair, Thierry Appourchaux, Michel Auvergne, Annie Baglin, Caroline Barban, Fréderic Baudin, Michaël Bazot, Tiago Campante, Claude Catala, William Chaplin, Orlagh Creevey, Sébastien Deheuvels, Noël Dolez, Yvonne Elsworth, Rafael García, Patrick Gaulme, Stéphane Mathis, Savita Mathur, Benoît Mosser, Clara Régulo, Ian Roxburgh, David Salabert, Réza Samadi, Kumiko Sato, Graham Verner, Shravan Hanasoge, and Katepalli R. Sreenivasan. Seismic constraints on rotation of Sun-like star and mass of exoplanet. PNAS, July 29, 2013 DOI: 10.1073/pnas.1303291110

Cite This Page:

New York University. "Pulsating star sheds light on exoplanet." ScienceDaily. ScienceDaily, 29 July 2013. <www.sciencedaily.com/releases/2013/07/130729161520.htm>.
New York University. (2013, July 29). Pulsating star sheds light on exoplanet. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2013/07/130729161520.htm
New York University. "Pulsating star sheds light on exoplanet." ScienceDaily. www.sciencedaily.com/releases/2013/07/130729161520.htm (accessed September 30, 2014).

Share This



More Space & Time News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Water You Drink Might Be Older Than The Sun

The Water You Drink Might Be Older Than The Sun

Newsy (Sep. 27, 2014) — Researchers at the University of Michigan simulated the birth of planets and our sun to determine whether water in the solar system predates the sun. Video provided by Newsy
Powered by NewsLook.com
First Woman Cosmonaut in 17 Years Blasts Off for ISS

First Woman Cosmonaut in 17 Years Blasts Off for ISS

AFP (Sep. 26, 2014) — A Russian Soyuz spacecraft carrying an American astronaut and two Russian cosmonauts, including the first woman cosmonaut in 17 years, blasted off on schedule Friday. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
Water Discovery On Small Planet Could Be Key To Earth 2.0

Water Discovery On Small Planet Could Be Key To Earth 2.0

Newsy (Sep. 25, 2014) — Scientists have discovered traces of water in the atmosphere of a distant, Neptune-sized planet. Video provided by Newsy
Powered by NewsLook.com
Raw: US-Russian Crew Lifts Off for Space Station

Raw: US-Russian Crew Lifts Off for Space Station

AP (Sep. 25, 2014) — A U.S.-Russian space crew has blasted off successfully for the International Space Station. The Russian Soyuz-TMA14M spacecraft lifted off from the Russian-leased Baikonur launch facility in Kazakhstan. (Sept. 25) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins