24/7 Space News
Discovery of planet too big for its sun throws off solar system formation models
An artistic rendering of the mass comparison of LHS 3154 system and our own Earth and sun.
Discovery of planet too big for its sun throws off solar system formation models
by Staff Writers
University Park PA (SPX) Dec 01, 2023

The discovery of a planet that is far too massive for its sun is calling into question what was previously understood about the formation of planets and their solar systems, according to Penn State researchers.

In a paper published online in the journal Science, researchers report the discovery of a planet more than 13 times as massive as Earth orbiting the "ultracool" star LHS 3154, which itself is nine times less massive than the sun. The mass ratio of the newly found planet with its host star is more than 100 times higher than that of Earth and the sun.

The finding reveals the most massive known planet in a close orbit around an ultracool dwarf star, the least massive and coldest stars in the universe. The discovery goes against what current theories would predict for planet formation around small stars and marks the first time a planet with such high mass has been spotted orbiting such a low-mass star.

"This discovery really drives home the point of just how little we know about the universe," said Suvrath Mahadevan, the Verne M. Willaman Professor of Astronomy and Astrophysics at Penn State and co-author on the paper. "We wouldn't expect a planet this heavy around such a low-mass star to exist."

He explained that stars are formed from large clouds of gas and dust. After the star is formed, the gas and dust remain as disks of material orbiting the newborn star, which can eventually develop into planets.

"The planet-forming disk around the low-mass star LHS 3154 is not expected to have enough solid mass to make this planet," Mahadevan said. "But it's out there, so now we need to reexamine our understanding of how planets and stars form."

The researchers spotted the oversized planet, named LHS 3154b, using an astronomical spectrograph built at Penn State by a team of scientists led by Mahadevan. The instrument, called the Habitable Zone Planet Finder or HPF, was designed to detect planets orbiting the coolest stars outside our solar system with the potential for having liquid water - a key ingredient for life - on their surfaces.

While such planets are very difficult to detect around stars like our sun, the low temperature of ultracool stars means that planets capable of having liquid water on their surface are much closer to their star relative to Earth and the sun. This shorter distance between these planets and their stars, combined with the low mass of the ultracool stars, results in a detectable signal announcing the presence of the planet, Mahadevan explained.

"Think about it like the star is a campfire. The more the fire cools down, the closer you'll need to get to that fire to stay warm," Mahadevan said. "The same is true for planets. If the star is colder, then a planet will need to be closer to that star if it is going to be warm enough to contain liquid water. If a planet has a close enough orbit to its ultracool star, we can detect it by seeing a very subtle change in the color of the star's spectra or light as it is tugged on by an orbiting planet."

Located at the Hobby-Eberly Telescope at the McDonald Observatory in Texas, the HPF provides some of the highest precision measurements to date of such infrared signals from nearby stars.

"Making the discovery with HPF was extra special, as it is a new instrument that we designed, developed and built from the ground-up for the purpose of looking at the uncharted planet population around the lowest mass stars," said Guomundur Stefansson, NASA Sagan Fellow in Astrophysics at Princeton University and lead author on the paper, who helped develop HPF and worked on the study as a graduate student at Penn State. "Now we are reaping the rewards, learning new and unexpected aspects of this exciting population of planets orbiting some of the most nearby stars."

The instrument has already yielded critical information in the discovery and confirmation of new planets, Stefansson explained, but the discovery of the planet LHS 3154b exceeded all expectations.

"Based on current survey work with the HPF and other instruments, an object like the one we discovered is likely extremely rare, so detecting it has been really exciting," said Megan Delamer, astronomy graduate student at Penn State and co-author on the paper. "Our current theories of planet formation have trouble accounting for what we're seeing."

In the case of the massive planet discovered orbiting the star LHS 3154, the heavy planetary core inferred by the team's measurements would require a larger amount of solid material in the planet-forming disk than current models would predict, Delamer explained. The finding also raises questions about prior understandings of the formation of stars, as the dust-mass and dust-to-gas ratio of the disk surrounding stars like LHS 3154 - when they were young and newly formed - would need to be 10 times higher than what was observed in order to form a planet as massive as the one the team discovered.

"What we have discovered provides an extreme test case for all existing planet formation theories," Mahadevan said. "This is exactly what we built HPF to do, to discover how the most common stars in our galaxy form planets - and to find those planets."

Other Penn State authors on the paper are Eric Ford, Brianna Zawadzki, Fred Hearty, Andrea Lin, Lawrence Ramsey and Jason Wright. Other authors on the paper are Joshua Winn of Princeton University, Yamila Miguel of the University of Leiden, Paul Robertson of the University of California, Irvine, and Rae Holcomb of the University of California, Shubham Kanodia of the Carnegie Institution for Science, Caleb Canas of the NASA Goddard Space Flight Center, Joe Ninan of India's Tata Institute of Fundamental Research, Ryan Terrien of Carleton College, Brendan Bowler, William Cochran, Michael Endl and Gary Hill of The University of Texas at Austin, Chad Bender of The University of Arizona, Scott Diddams, Connor Fredrick and Andrew Metcalf of the University of Colorado, Samuel Halverson of California Institute of Technology's Jet Propulsion Laboratory, Andrew Monson of the University of Arizona, Arpita Roy of Johns Hopkins University, Christian Schwab of Australia 's Macquarie University, and Gregory Zeimann of the Hobby-Eberly Telescope at UT Austin.

Research Report:A Neptune-mass exoplanet in close orbit around a very low mass star challenges formation models

Related Links
Penn State
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Subscribe Free To Our Daily Newsletters

The following news reports may link to other Space Media Network websites.
Webb study reveals rocky planets can form in extreme environments
Paris (ESA) Dec 01, 2023
An international team of astronomers have used the NASA/ESA/CSA James Webb Space Telescope to provide the first observation of water and other molecules in the inner, rocky-planet-forming regions of a disc in one of the most extreme environments in our galaxy. These results suggest that the conditions for rocky-planet formation, typically found in discs in regions where low-mass stars are formed, can also occur in regions where massive stars are formed and possibly in a broader range of environmen ... read more

Axiom Space Chooses AWS to Power IT Infrastructure for Commercial Space Station

Was going to space a good idea

Sierra Space's Shooting Star Module Begins Rigorous Testing at NASA Facility

Russian Progress 86 spacecraft lifts off with supplies for ISS

NASA Continues Progress on Artemis III Rocket Adapter with Key Joint Installation

NASA Tests In-Flight Capability of Artemis Moon Rocket Engine

Sidus Space and Bechtel join forces for Artemis Mobile Launcher 2

NASA, small companies eye new cargo delivery, heat shield technologies

Mapping Mars: Deep Learning Could Help Identify Jezero Crater Landing Site

MAHLI Marathon: Sols 4025-4027

Should I Stay or Should I Go Now: Sols 4028-4029

Farewell, Solar Conjunction 2023: Sols 4023-4024

CAS Space expands into Guangdong with new rocket engine testing complex

China's Lunar Samples on Display in Macao to Inspire Future Explorers

China Manned Space Agency Delegation Highlights SARs' Role in Space Program

Wenchang Set to Become China's Premier Commercial Space Launch Hub by Next Year

Embry-Riddle's Innovative Mission Control Lab prepares students for booming space sector

Ovzon and SSC close to sealing satellite communication contract worth $10M

A major boost for space skills and research in North East England

GalaxySpace to boost mobile broadband with new-gen satellite technology

CityU develops universal metasurface antenna, advancing 6G communications

The Rise of the Virtual Mission

LeoLabs Partners with Aalyria to enhance global communication network security

Tracking undetectable space junk

Discovery of planet too big for its sun throws off solar system formation models

Ariel moves from drawing board to construction phase

Webb study reveals rocky planets can form in extreme environments

Can signs of life be detected from Saturn's frigid moon?

Unwrapping Uranus and its icy moon secrets

Juice burns hard towards first-ever Earth-Moon flyby

Fall into an ice giant's atmosphere

Juno finds Jupiter's winds penetrate in cylindrical layers

Subscribe Free To Our Daily Newsletters


The content herein, unless otherwise known to be public domain, are Copyright 1995-2023 - 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.