Science Current Events | Science News | Brightsurf.com
 

UF astronomer: Some giant planets in other systems most likely to be alone

May 08, 2012
GAINESVILLE, Fla. - "Hot Jupiter-type" planets are most likely to be alone in their systems, according to research by a University of Florida astronomer and others, made public today.

"Hot Jupiters" are giant planets beyond our solar system, roughly the size of Jupiter but orbiting close to their parent stars and thus much hotter than the Earth or Jupiter, said UF professor Eric Ford. They have very short orbital periods, completing a turn around their stars in fewer than 10 days. This study, published in the journal Proceedings of the National Academy of Sciences, provides new insights into how they are formed.

This research used information gathered by NASA's planet-hunting Kepler mission, which uses a 1-meter space telescope to stare constantly at a patch of the Milky Way, registering the small decreases in the light from stars caused when a planet crosses in front of it.

Scientists dug into Kepler's data and selected a sample of 63 planetary systems containing previously detected hot Jupiter candidates. Then they looked for signals of additional planets either crossing in front of the host stars or gravitationally tugging on the hot Jupiter's orbit. In all cases they found no evidence of additional planets. To allow comparisons, they used the same methods to study a sample of "warm Jupiter" candidates, equally big planets but located farther away from their parent stars and "hot Neptunes," smaller but closer to the stars. They found compelling evidence that at least 10 percent of the warm Jupiters and one third of the hot Neptunes have other planetary companions nearby in the system. Thus, why are all the hot Jupiters so lonely?

Astronomers believe it results from the way the hot Jupiters are formed, now thought to be different from most other planets. Current models suggest that they are probably formed farther away from their host star, and then gravitational interactions with another body cause their orbits to become highly elongated. Each orbit the hot Jupiter passes very close to the host star and then travels far away. The star raises tides on the planet, repeatedly stretching it and causing its orbit to become smaller and more circular. This process would remove or destroy other low-mass planets that originally formed between the star and the giant planet.

"We looked for companion planets near hot Jupiters in order to learn a bit more about their formation," Ford said. "The lack of nearby planets supports the theory that a close encounter with another body in the system caused the elongation of the orbit. When a giant planet repeatedly passes through the inner regions of a planetary system on an elongated orbit, it would wreak great havoc on any planets that had formed there. The other planets would either fall into the star, collide with the hot Jupiter or be kicked out of the system via a gravitational slingshot."

In 1995 the first planet orbiting a sun-like star was discovered. It and most exoplanets found in the early days of the exoplanet search happened to be hot Jupiters.

"That was because they are easier to find than smaller planets or others more distant to their host star," Ford said. "Now, we know that less than 1 percent of stars harbor hot Jupiters, so they are relatively rare. A special sequence of events like strong gravitational interactions between two giant planets followed by tidal circularization seems to be the most plausible scenario for the formation of hot Jupiters."

The research was led by Jason Steffen from the Fermilab Center for Particle Astrophysics.

NASA's Kepler Mission, operating since 2009, is revolutionizing the field of planetary science. For the first time it is enabling astronomers to conduct this kind of detailed population studies of planet candidates. By allowing astronomers to study systems other than our own, they are able to confront planet formation theories with observational data, giving important insights into the range of contemporary planetary system architectures and the possible existence of habitable planets within them.

University of Florida


Related Giant Planets Current Events and Giant Planets News Articles


Hubble Finds Three Surprisingly Dry Exoplanets
Astronomers using NASA's Hubble Space Telescope have gone looking for water vapor in the atmospheres of three planets orbiting stars similar to the sun -- and have come up nearly dry.

Highest-precision measurement of water in planet outside the solar system
A team of astronomers using NASA's Hubble Space Telescope have gone looking for water vapour in the atmospheres of three planets orbiting stars similar to the Sun - and have come up nearly dry.

Transiting Exoplanet with Longest Known Year
Astronomers have discovered a transiting exoplanet with the longest known year. Kepler-421b circles its star once every 704 days.

Peering into giant planets from in and out of this world
Lawrence Livermore scientists for the first time have experimentally re-created the conditions that exist deep inside giant planets, such as Jupiter, Uranus and many of the planets recently discovered outside our solar system.

NASA Finds Friction from Tides Could Help Distant Earths Survive, and Thrive
As anybody who has started a campfire by rubbing sticks knows, friction generates heat. Now, computer modeling by NASA scientists shows that friction could be the key to survival for some distant Earth-sized planets traveling in dangerous orbits.

Cracks in Pluto's Moon Could Indicate it Once Had an Underground Ocean
If the icy surface of Pluto's giant moon Charon is cracked, analysis of the fractures could reveal if its interior was warm, perhaps warm enough to have maintained a subterranean ocean of liquid water, according to a new NASA-funded study.

Astronomers identify signature of Earth-eating stars
Some Sun-like stars are 'Earth-eaters.' During their development they ingest large amounts of the rocky material from which 'terrestrial' planets like Earth, Mars and Venus are made.

Mysteries of a nearby planetary system's dynamics now are solved
Mysteries of one of the most fascinating nearby planetary systems now have been solved, report authors of a scientific paper to be published by the journal Monthly Notices of the Royal Astronomical Society in its early online edition on 22 April 2014.

Lick's Automated Planet Finder: First robotic telescope for planet hunters
Lick Observatory's newest telescope, the Automated Planet Finder (APF), has been operating robotically night after night on Mt. Hamilton since January, searching nearby stars for Earth-sized planets.

Detection of Water Vapor in the Atmosphere of a Hot Jupiter
Although liquid water covers a majority of Earth's surface, scientists are still searching for planets outside of our solar system that contain water.
More Giant Planets Current Events and Giant Planets News Articles

Galactic Hoppers #1: Planet of Giants

Galactic Hoppers #1: Planet of Giants


The Galactic Hoppers' very first out-of-this-world space adventure!

That's where Suzanne, Richard and David find themselves when the magic whirlpool spirals them to a strange new Planet of Giants. Will they ever get back to Earth or will they become alien dinner?


Mass Destruction: The Men and Giant Mines That Wired America and Scarred the Planet

Mass Destruction: The Men and Giant Mines That Wired America and Scarred the Planet
by Professor Timothy J. LeCain (Author)


The place: The steep mountains outside Salt Lake City. The time: The first decade of the twentieth century. The man: Daniel Jackling, a young metallurgical engineer. The goal: A bold new technology that could provide billions of pounds of cheap copper for a rapidly electrifying America. The result: Bingham's enormous "Glory Hole," the first large-scale open-pit copper mine, an enormous chasm in the earth and one of the largest humanmade artifacts on the planet. Mass Destruction is the compelling story of Jackling and the development of open-pit hard rock mining, its role in the wiring of an electrified America, as well its devastating environmental consequences.Mass destruction mining soon spread around the nation and the globe, providing raw materials essential to the mass production and...

Planet Earth Giant Coloring & Activity Book ~ Wildlife Wonders (Our Extraordinary World)

Planet Earth Giant Coloring & Activity Book ~ Wildlife Wonders (Our Extraordinary World)
by Modern publishing (Author)


Giant coloring and activity book

The Planet of the Giant (The Little Prince)

The Planet of the Giant (The Little Prince)
by Gilles Adrien (Author), Alain Broders (Author)


The Planet of the Giant is a very strange place. The planet itself is a stone giant, and each body part is managed by a different ruler. But ever since Talamus, the controller of the giant's brain, stopped responding to messages and started giving crazy orders, nothing on the planet is working anymore . . .

The Planets

The Planets
by DK Publishing (Author)


Featuring all-new 3D models built using data gathered by NASA and the European Space Agency, The Planets is an awe-inspiring journey through the Solar System, from Earth to Mars and beyond. Viewed layer by layer, planets and other objects in the Solar System are taken out of the night sky and presented on a white background, revealing every detail of their surface and internal anatomy in astonishing detail. Looking at planets, the Sun, hundreds of moons and thousands of asteroids and comets, The Planets includes timelines that chronicle all major Space missions, right up to the latest Mars rovers, and infographics that present fascinating facts about all planets and the Solar System in a fresh new way.

Planet Earth Giant Coloring & Activity Book ~ Exciting Earth (Our Extraordinary World)

Planet Earth Giant Coloring & Activity Book ~ Exciting Earth (Our Extraordinary World)
by bbc (Author)


This book celebrates the magnificent imagery of Planet Earth, the groundbreaking documentary that inspires with the incredible wonder, beauty, & spirit of nature.

Doctor Who: Planet of Giants

Doctor Who: Planet of Giants
by Terrance Dicks (Author)




Planet Dinosaur: The Next Generation of Killer Giants

Planet Dinosaur: The Next Generation of Killer Giants
by Cavan Scott (Author)


The companion book to the upcoming Discovery Channel television series, Planet Dinosaur is an introduction to the latest and most exciting dinosaur discoveries. The last decade has been particularly fruitful in the study of dinosaurs, with more new species found than were discovered in the preceding 200 years. Many of these discoveries easily eclipse previously known species and are rewriting what we know about dinosaurs. Planet Dinosaur is a global survey of the 30 most thrilling dinosaur species found in recent years. It provides a new global perspective on dinosaurs, revealing which species lived at the same time on different continents and how the Earth looked in each time period. Specimens in China, the Sahara, the Arctic, Antarctica and North America are especially exciting....

The Giant Planet Jupiter (Practical Astronomy Handbooks)

The Giant Planet Jupiter (Practical Astronomy Handbooks)
by John H. Rogers (Author)


Jupiter is an extraordinarily colourful and dynamic planet. Over minutes, one can watch tiny shadows cast by its moons slide over its surface; over days and weeks parades of diverse, giant swirling storms can be seen to move and evolve. It is because of this richness of visual and physical properties that Jupiter has intrigued amateur and professional astronomers and has been the goal of several space missions. This highly illustrated volume provides a comprehensive and accessible account of Jupiter and its satellites. It reviews systematic telescopic observations that have stretched over more than a hundred years, in addition to modern observations and theories, and the wealth of data from the Pioneer, Voyager and Ulysses space missions. As well as a thorough survey of the planet's...

Planet of Giants (Doctor Who Series)

Planet of Giants (Doctor Who Series)


The TARDIS doors open while the ship is still in flight by accident. Although they have arrived back on Earth in the 1960s, a time they have been trying to return to since they all met, the travellers soon realise that something is very wrong.

The Doctor, Ian, Barbara and Susan discover that they have all be reduced in size and the world they are now exploring has dangers at every turn…

© 2014 BrightSurf.com