Wobbly spinning top planet found
12 Mar 2014 by hddbqtthcb.d hddbqtthcb.d
NASA’s Kepler space telescope has spotted a wobbly planet akin to a child’s spinning top near the constellation of Cygnus.
Kepler-413b precesses or wobbles on its axis wildly; the tilt of its spin axis can vary as much as 30 degrees over 11 years. The planet orbits a close pair of orange and red dwarf stars every 66 days – and appears to wobble around these too as the plane of its orbit is tilted 2.5 degrees with respect to the star pair’s orbit. As seen from Earth, the planet seems to wobble up and down continuously.
Kepler finds planets by observing the dimming of stars when planets transit in front of them; normally this happens like clockwork but an unusual pattern of transiting for Kepler-413b alerted astronomers to the wobbling.
“Looking at the Kepler data over the course of 1,500 days, we saw three transits in the first 180 days – one transit every 66 days – then we had 800 days with no transits at all,” said Veselin Kostov, principal investigator from the Space Telescope Science Institute and John Hopkins University. “After that we saw five more transits in a row.”
Because the orbit wobbles up and down to such a great degree, Kepler-413b sometimes doesn’t transit the stars as viewed from Earth; the next transit visible from Earth is expected in 2020.
Astronomers are still trying to figure out why this planet is out of alignment with its stars: other planetary bodies have tilted the axis or a third star nearby that is a visual companion could be gravitationally bound to the system and exerting an influence.
“Presumably there are planets out there like this one that we’re not seeing because we’re in the unfavourable period,” said Peter McCullough. “And that’s one of the things that Veselin is researching; Is there a silent majority of things that we’re not seeing.”
Kepler-413b is unlikely to be habitable: it undergoes erratic season changes and will be too warm for life, and for liquid water to exist. It’s also a super Neptune with a mass 65 times that of Earth – so there is no surface to stand on.
