. 24/7 Space News .
NASA's TESS helps astronomers study red-giant stars, examine a too-close planet
by Staff Writers
Ames IA (SPX) Nov 20, 2019

Recent TESS panorama of the souther sky.

NASA's planet-hunting TESS Mission keeps giving astronomers new realities to examine and explain.

Case in point: astronomers using the tools of asteroseismology - the observations and measurements of a star's oscillations, or starquakes, that appear as changes in brightness - have learned more about two stars bright enough to be visible in a dark sky to the naked eye. These red-giant stars - older, "retired" stars no longer burning hydrogen in their cores - are known as HD 212771 and HD 203949.

Both stars are known to host their own planets. And the TESS data indicate one of those "exoplanets" (the general term for planets that orbit stars other than our sun) is so close to its host star it shouldn't have survived the star's expansion as a red giant - if, that is, the star is old enough to have expanded and retreated.

Steve Kawaler, an Iowa State University distinguished professor of physics and astronomy, and Miles Lucas, a recent Iowa State graduate and current doctoral student at the University of Hawaii at Manoa, are part of the TESS asteroseismology study team.

"We listened to the notes the stars were singing," Kawaler said. "We used that data to determine actual values - mass, radius and evolutionary stage - for these stars. Asteroseismology can tell us all these things - and more - about stars that are difficult to obtain with other tools."

The team of 48 astronomers describe their findings in a paper recently published by The Astrophysical Journal. The lead author is Tiago L. Campante of Portugal's Universidade do Porto.

The paper describes the first use of TESS data to detect oscillations of stars already known to host exoplanets. The new work, the authors wrote, is a way of "further showcasing the mission's potential to conduct asteroseismology of red-giant stars."

Kawaler said the study indicated star HD 203949 was less massive than previously thought. That meant for its planet to be moving as fast as the astronomers determined, it had to be much closer to the star than expected. So close, in fact, it would be engulfed by the star's expansion as a red giant.

The paper offers two possible explanations: The host star is early in its red giant expansion and has yet to engulf and destroy the planet. Or, computer simulations of star-planet tides indicate the planet could have been dragged from a wider orbit, where it avoided destruction by the star, and then settled into a closer orbit once the star retreated.

It's an interesting case of planetary evolution, said Kawaler, who's on the seven-member board leading the TESS Asteroseismic Science Consortium. Jorgen Christensen-Dalsgaard of Aarhus University in Denmark is the consortium's lead investigator.

"Tiago (the paper's lead author) has a knack for finding these planetary systems that expand our horizons on how nature makes planets and keeps them," Kawaler said.

As astronomers continue to analyze data for clues about how planets and stars evolve with each other, Kawaler said TESS is an important tool.

TESS - the Transiting Exoplanet Survey Satellite, led by astrophysicists from the Massachusetts Institute of Technology - launched in April 2018. The spacecraft and its four cameras are on a two-year mission to survey 85 percent of the sky, looking for planets by detecting tiny dips of light as they pass in front of their host stars.

Those cameras also collect star data that are useful for planetary studies, too.

"Characterization of host stars is a critical component of understanding their planets," the authors wrote. " ... The asteroseismology techniques described here are thus an important component of overall planetary system characterization."

Research paper

Related Links
TESS Mission
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only
SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Scientists use 3D climate model to narrow search for habitable exoplanets
Washington (UPI) Nov 14, 2019
For the first time, scientists used a 3D climate model that incorporates photochemistry to study the habitability of exoplanets surrounding M dwarf stars. The findings - published Thursday in the Astrophysical Journal - could help planetary scientists know what to look for when surveying potentially habitable exoplanets. Researchers adopted a 3D climate model, originally developed by scientists at the University of Colorado-Boulder, for the study of Earth's climate, to simulate the atm ... read more

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Audit criticizes NASA for payments to Boeing in human spaceflight program

NASA overpaid Boeing by hundreds of millions of dollars: auditor

US has paid Russia 4 billion dollars to transport astronauts to ISS

Stand-up scientists use comedy to reach beyond the ivory tower

Roscosmos creates rocket-monitoring system using technology found in smart homes

China sends five satellites into orbit via single rocket

SpaceX Crew Dragon releases photos of emergency escape engines test

Arianespace will orbit TIBA-1 and Inmarsat GX5 with Ariane 5

Human Missions to Mars

Mars scientists investigate ancient life in Australia

China completes Mars lander test ahead of 2020 mission

At future Mars landing spot, scientists spy mineral that could preserve signs of past life

China plans to complete space station construction around 2022: expert

China conducts hovering and obstacle avoidance test in public for first Mars lander mission

Beijing eyes creating first Earth-Moon economic zone

China conducts simulated weightlessness experiment for long-term stay in space

China sends two global multimedia satellites into planned orbit

Tesla Completes Acquisition of Maxwell Technologies

Space Talks 2019: bringing space to you

EU must boost spending in space or be squeezed out: experts

Headwall and geo-konzept Announce Hyperspectral Remote-Sensing Center in Europe

Amazon says 'bias' in Pentagon awarding $10 bn contract to Microsoft

Amazon says 'bias' in Pentagon awarding $10 bn contract to Microsoft

Multimaterial 3D printing manufactures complex objects, fast

Making planets in a rocket

Scientists use 3D climate model to narrow search for habitable exoplanets

Distant worlds under many suns

Study refines which exoplanets are potentially habitable

NASA finds Neptune moons locked in 'Dance of Avoidance'

NASA scientists confirm water vapor on Europa

New Horizons Kuiper Belt Flyby object officially named 'Arrokoth'

NASA renames faraway ice world 'Arrokoth' after backlash

The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.