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Lava World Baffles Astronomers: Planet Kepler-78b ‘Shouldn’t Exist’
Kepler-78b is a planet that shouldn’t exist. This scorching lava world circles its star every eight and a half hours at a distance of less than one million miles — one of the tightest known orbits. According to current theories of planet formation, it couldn’t have formed so close to its star, nor could it have moved there.
“This planet is a complete mystery,” says astronomer David Latham of the Harvard-Smithsonian Center for Astrophysics (CfA). “We don’t know how it formed or how it got to where it is today. What we do know is that it’s not going to last forever.”
“Kepler-78b is going to end up in the star very soon, astronomically speaking,” agrees CfA astronomer Dimitar Sasselov.
Not only is Kepler-78b a mystery world, it is the first known Earth-sized planet with an Earth-like density. Kepler-78b is about 20 percent larger than Earth, with a diameter of 9,200 miles, and weighs almost twice as much. As a result it has a density similar to Earth’s, which suggests an Earth-like composition of iron and rock.
Read more: http://www.sciencedaily.com/releases/2013/10/131030142915.htm
NASA’s Kepler Discovers Multiple Planets Orbiting a Pair of Stars
ScienceDaily (Aug. 28, 2012) — Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, NASA’s Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. This system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus.
This discovery proves that more than one planet can form and persist in the stressful realm of a binary star and demonstrates the diversity of planetary systems in our galaxy.
Astronomers detected two planets in the Kepler-47 system, a pair of orbiting stars that eclipse each other every 7.5 days from our vantage point on Earth. One star is similar to the sun in size, but only 84 percent as bright. The second star is diminutive, measuring only one-third the size of the sun and less than 1 percent as bright.
Read more: http://www.sciencedaily.com/releases/2012/08/120828190127.htm
Proximity of New Planets Stuns Even Astronomers
“We’ve never known of planets like this,” said Yale University astronomer Sarbani Basu, a member of the research team that analyzed the system. “If you were on the smaller planet looking up, the larger planet would seem more than twice the size of Earth’s full moon. It would be jaw-dropping.”
Basu’s research focused on determining the properties of the planets’ host star — work that was essential for discerning the characteristics of the orbiting planets.
The 46-member, international team, led by astronomers at Harvard and the University of Washington, report their discovery June 21 in Science Express, the early release version of the journal Science.
Read mode : http://www.sciencedaily.com/releases/2012/06/120621152307.htm
Nasa’s Kepler telescope finds planet orbiting two suns
16 September 2011 Last updated at 00:52 GMT
An artist’s conception of Kepler-16bA planet orbiting two suns – the first confirmed alien world of its kind – has been found by Nasa’s Kepler telescope, the US space agency announced.
It may resemble the planet Tatooine from the film Star Wars, but scientists say Luke Skywalker, or anyone at all, is unlikely to be living there.
Named Kepler-16b, it is thought to be an uninhabitable cold gas giant, like Saturn.
The newly detected body lies some 200 light years from Earth.
Though there have been hints in the past that planets circling double stars might exist – “circumbinary planets”, as they are known – scientists say this is the first confirmation.
It means when the day ends on Kepler-16b, there is a double sunset, they say.
‘Stunning’
Kepler-16b’s two suns are smaller than ours – at 69% and 20% of the mass of our Sun – making the surface temperature an estimated -100 to -150F (-73 to -101C).
The planet eclipses, or transits, both stars; and the stars regularly eclipse each other tooThe planet orbits its two suns every 229 days at a distance of 65m miles (104m km) – about the same distance out as Venus.
The Kepler telescope, launched in 2009, is designed to scour our section of the Milky Way for Earth-like planets.
“This is really a stunning measurement by Kepler,” said Alan Boss of the Carnegie Institution for Science near Washington DC, a co-author of the study.
“The real exciting thing is there’s a planet sitting out there orbiting around these two stars.”
Kepler finds stars whose light is regularly dimmed when an orbiting planet passes between the star and the telescope.
In this case, the team was also able to observe dimming when one star passed in front of the other.
Nasa’s scientists saw additional dips in the light in both stars at alternating but regular times, confirming the dual orbit of the planet.
Data collected by the Kepler telescope allows for very precise measurements of the mass, radius and trajectories of all three bodies – the best ever estimates of a extra-solar planet.
The finding was reported in Friday’s issue of the journal Science.
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