Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pulsating Star Sheds Light on Exoplanet

31.07.2013
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.


Image courtesy of MPI for Solar System Research/Mark A. Garlick (www.markgarlick.com).

An artistic rendering of HD 52265 and its orbiting Jupiter-like planet.

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 the 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.

James Devitt | Newswise
Further information:
http://www.nyu.edu

Further reports about: Exoplanet LIGHT Max Planck Institute NYU PNAS Princeton Pulsating Solar Decathlon Space brown dwarf

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>