World Bulletin / News Desk
A joint effort of citizen scientists and professional astronomers has led to the first reported case of a planet orbiting twin suns that in turn is orbited by a second distant pair of stars.
Aided by volunteers using the Planethunters.org website, a Yale-led international team of astronomers identified and confirmed discovery of the phenomenon, called a circumbinary planet in a four-star system.
Only six planets are known to orbit two stars, according to researchers, and none of these are orbited by distant stellar companions.
“Circumbinary planets are the extremes of planet formation,” said Meg Schwamb of Yale, lead author of a paper about the system presented Oct. 15 at the annual meeting of the Division for Planetary Sciences of the American Astronomical Society in Reno, Nevada.
“The discovery of these systems is forcing us to go back to the drawing board to understand how such planets can assemble and evolve in these dynamically challenging environments.”
Dubbed PH1, the planet was first identified by citizen scientists participating in Planet Hunters, a Yale-led program that enlists members of the public to review astronomical data from NASA’s Kepler spacecraft for signs of planets. It is the project’s first confirmed planet discovery.
The volunteers — Kian Jek of San Francisco and Robert Gagliano of Cottonwood, Arizona — spotted faint dips in light caused by the planet as it passed in front of its parent stars, a common method of finding extrasolar planets. Schwamb, a Yale postdoctoral researcher, led the team of professional astronomers that confirmed the discovery and characterized the planet, following observations from the Keck telescopes on Mauna Kea, Hawaii. PH1 is a gas giant with a radius about 6.2 times that of Earth, making it a bit bigger than Neptune.
"Planet Hunters is a symbiotic project, pairing the discovery power of the people with follow-up by a team of astronomers,” said Debra Fischer, a professor of astronomy at Yale and planet expert who helped launch Planet Hunters in 2010. “This unique system might have been entirely missed if not for the sharp eyes of the public."
An artist's illustration of PH1, a planet discovered by volunteers from the Planet Hunters citizen science project. PH1, shown in the foreground, is a circumbinary planet and orbits two suns. (Image by Haven Giguere/Yale)
PH1 orbits outside the 20-day orbit of a pair of eclipsing stars that are 1.5 and 0.41 times the mass of the Sun. It revolves around its host stars roughly every 138 days. Beyond the planet’s orbit at about 1000 AU (roughly 1000 times the distance between Earth and the Sun) is a second pair of stars orbiting the planetary system.
“The thousands of people who are involved with Planet Hunters are performing a valuable service,” said coauthor Jerome Orosz, who earned his Ph.D. at Yale in 1996 and is now associate professor of astronomy at San Diego State University. “Many of the automated techniques used to find interesting features in the Kepler data don't always work as efficiently as we would like. The hard work of the Planet Hunters helps ensure that important discoveries are not falling through the cracks."
The research was supported by NASA and the National Science Foundation Astronomy and Astrophysics Postdoctoral Fellowship.
Spanish news publishers want government to negotiate with Google.
The Russian space station Mir, launched by the Soviet Union in 1986, operated until 2001 and President Vladimir Putin is now seeking to reform Russia's once-pioneering space industry
Google's action caps a decade of acrimony with news publishers who blame the search giant for revenue and readership declines
Top climate envoy gives broad support for global deal but says country's "special circumstances" must be factored.
Finnish cyber-security expert tells Istanbul audience that people have made gigantic IT companies billions in profits by providing private data for services.
The scientific observation of Pluto, its entourage of moons and other bodies in the solar system's frozen backyard begins Jan. 15
For the first time in more than 40 years, NASA has launched a spaceship designed to carry astronauts far beyond Earth
Benefits of digital revolution outweigh risks, Germany’s Chancellor says
Last month, Prime Minister Ahmet Davutoglu vowed to make climate change a top priority when Turkey hosts next year’s G20 summit
The emails of Apple’s late CEO is being used as evidence in antitrust claim.
The report said the malware overrides data on hard drives of computers and can make them inoperable and shut down networks.
Among those hit were the London newspapers Daily Telegraph, Independent and Evening Standard, which reported that other news organisations had also been targeted.
The European Union's privacy watchdogs agreed on a set of guidelines to help them implement a ruling from Europe's supreme court that gives people the right to ask search engines to remove personal information
Iraq bars private companies from owning fixed networks transiting domestic data and anything they build is usually seized by the government.
The new crew faces a busy six months in orbit, including a trio of spacewalks to prepare the station for a new fleet of U.S. commercial space taxis