Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




EXO WORLDS
Astronomers discover planet that shouldn't be there
by Staff Writers
Tucson AZ (SPX) Dec 10, 2013


This is a discovery image of HD 106906 b in the thermal infrared (4um wavelength) from MagAO/Clio2, processed to remove the bright light from its host star, HD 106906 A. The planet is than 20 times farther away from HD 106906 A than Neptune is from our Sun. AU stands for Astronomical Unit, the average distance of the Earth and the Sun. Credit: Vanessa Bailey.

An international team of astronomers, led by a University of Arizona graduate student, has discovered the most distantly orbiting planet found to date around a single, sun-like star. It is the first exoplanet - a planet outside of our solar system - discovered at the UA.

Weighing in at 11 times Jupiter's mass and orbiting its star at 650 times the average Earth-Sun distance, planet HD 106906 b is unlike anything in our own Solar System and throws a wrench in planet formation theories.

"This system is especially fascinating because no model of either planet or star formation fully explains what we see," said Vanessa Bailey, who led the research. Bailey is a fifth-year graduate student in the UA's Department of Astronomy.

It is thought that planets close to their stars, like Earth, coalesce from small asteroid-like bodies born in the primordial disk of dust and gas that surrounds a forming star. However, this process acts too slowly to grow giant planets far from their star.

Another proposed mechanism is that giant planets can form from a fast, direct collapse of disk material. However, primordial disks rarely contain enough mass in their outer reaches to allow a planet like HD 106906 b to form. Several alternative hypotheses have been put forward, including formation like a mini binary star system.

"A binary star system can be formed when two adjacent clumps of gas collapse more or less independently to form stars, and these stars are close enough to each other to exert a mutual gravitation attraction and bind them together in an orbit," Bailey explained.

"It is possible that in the case of the HD 106906 system the star and planet collapsed independently from clumps of gas, but for some reason the planet's progenitor clump was starved for material and never grew large enough to ignite and become a star."

According to Bailey, one problem with this scenario is that the mass ratio of the two stars in a binary system is typically no more than 10-to-1.

"In our case, the mass ratio is more than 100-to-1," she explained. "This extreme mass ratio is not predicted from binary star formation theories - just like planet formation theory predicts that we cannot form planets so far from the host star."

This system is also of particular interest because researchers can still detect the remnant "debris disk" of material left over from planet and star formation.

"Systems like this one, where we have additional information about the environment in which the planet resides, have the potential to help us disentangle the various formation models," Bailey added. "Future observations of the planet's orbital motion and the primary star's debris disk may help answer that question."

At only 13 million years old, this young planet still glows from the residual heat of its formation. Because at 2,700 Fahrenheit (about 1,500 degrees Celsius) the planet is much cooler than its host star, it emits most of its energy as infrared rather than visible light. Earth, by comparison, formed 4.5 billion years ago and is thus about 350 times older than HD 106906 b.

Direct imaging observations require exquisitely sharp images, akin to those delivered by the Hubble Space Telescope. To reach this resolution from the ground requires a technology called Adaptive Optics, or AO. The team used the new Magellan Adaptive Optics (MagAO) system and Clio2 thermal infrared camera - both technologies developed at the UA - mounted on the 6.5 meter-diameter Magellan telescope in the Atacama Desert in Chile to take the discovery image.

UA astronomy professor and MagAO principal investigator Laird Close said: "MagAO was able to utilize its special Adaptive Secondary Mirror, with 585 actuators, each moving 1,000 times a second, to remove the blurring of the atmosphere. The atmospheric correction enabled the detection of the weak heat emitted from this exotic exoplanet without confusion from the hotter parent star."

"Clio was optimized for thermal infrared wavelengths, where giant planets are brightest compared to their host stars, meaning planets are most easily imaged at these wavelengths," explained UA astronomy professor and Clio principal investigator Philip Hinz, who directs the UA Center for Astronomical Adaptive Optics.

The team was able to confirm that the planet is moving together with its host star by examining Hubble Space Telescope data taken eight years prior for another research program. Using the FIRE spectrograph, also installed at the Magellan telescope, the team confirmed the planetary nature of the companion.

"Images tell us an object is there and some information about its properties but only a spectrum gives us detailed information about its nature and composition," explained co-investigator Megan Reiter, a graduate student in the UA Department of Astronomy. "Such detailed information is rarely available for directly imaged exoplanets, making HD 106906 b a valuable target for future study."

"Every new directly detected planet pushes our understanding of how and where planets can form," said co-investigator Tiffany Meshkat, a graduate student at Leiden Observatory in the Netherlands.

"This planet discovery is particularly exciting because it is in orbit so far from its parent star. This leads to many intriguing questions about its formation history and composition. Discoveries like HD 106906 b provide us with a deeper understanding of the diversity of other planetary systems."

The research paper, "HD 106906 b: A Planetary-mass Companion Outside a Massive Debris Disk," has been accepted for publication in The Astrophysical Journal Letters and will appear in a future issue. An online version is available for download at http://arxiv.org/abs/1312.1265 .

The members of the discovery team are Vanessa Bailey (UA), Tiffany Meshkat (Leiden Observatory [LO]), Megan Reiter (UA), Katie Morzinski (UA), Jared Males (UA), Kate Y. L. Su (UA), Philip M. Hinz (UA), Matthew Kenworthy (LO), Daniel Stark (UA), Eric Mamajek (University of Rochester), Runa Briguglio (Arcetri Observatory [AO]), Laird M. Close (UA), Katherine B. Follette (UA), Alfio Puglisi (AO), Timothy Rodigas (UA, Carnegie Institute of Washington [CIW]), Alycia J. Weinberger (CIW), and Marco Xompero (AO).

.


Related Links
MagAO system
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

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




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EXO WORLDS
Hot Jupiters Highlight Challenges in the Search for Life Beyond Earth
Baltimore MD (SPX) Dec 09, 2013
This week, the Goddard Center for Astrobiology celebrated the confirmation of atmospheric water on five exoplanets. This discovery heralds a new era in planet hunting at the same time as it acknowledge two conundrums, one old and one new. The new problem directly involves the water signals themselves. While undoubtedly present, on each of the five planets the signal appears to be actively ... read more


EXO WORLDS
Silent Orbit for China's Moon Lander

China's most moon-like place

LADEE Instruments Healthy and Ready for Science

China launches first moon rover mission

EXO WORLDS
Bid to colonize Mars wins high-profile backing

MRO Reveals A More Dynamic Red Planet

Mars One spaceflight project 'can succeed'

Opportunity ascending Solander Point at rim of Endeavour Crater

EXO WORLDS
Heat Shield for NASA's Orion Spacecraft Arrives at Kennedy Space Center

Space exploration can drive the next agricultural revolution

Global patent growth hits 18-year high

Facebook joins NYU in artificial intelligence lab

EXO WORLDS
China moon rover enters lunar orbit: Xinhua

Turkey keen on space cooperation with China

China space launch debris wrecks villagers' homes: report

Designer: moon rover uses cutting-edge technology

EXO WORLDS
New crew to run space station in March

Russian android may take on outer space operations at ISS

Repurposing ISS Trash for Power and Water

Russian spacecraft with advanced navigation system docks with ISS

EXO WORLDS
Kazakhstan to end Proton missions in 2025

Russian Proton-M rocket launches Inmarsat-5F1 satellite

Basic build-up is being completed for Arianespace's Soyuz to launch Gaia

Third time a charm: SpaceX launches commercial satellite

EXO WORLDS
Astronomers discover planet that shouldn't be there

Hot Jupiters Highlight Challenges in the Search for Life Beyond Earth

Astronomers find strange planet orbiting where there shouldn't be one

Hubble Traces Subtle Signals of Water on Hazy Worlds

EXO WORLDS
Google opens first data centres in Asia

Berkeley Lab Researchers Create a Nonlinear Light-generating Zero-Index MetaMaterial

First Boeing-built Inmarsat-5 Global Xpress Satellite Sends Initial On-Orbit Signals

New setback for Canadian gold mine plan




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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. 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. Privacy Statement