Neptune-sized exoplanet discovered around bright star

Written by PTI | London | Updated: Jan 24 2014, 00:47am hrs
ExoplanetScientists have discovered a new Neptune-sized exoplanet in a double star system. Reuters
Scientists have discovered a new Neptune-sized exoplanet in a double star system, 425 light years from Earth.

An international team of astronomers at Stellar Astrophysics Centre in Aarhus, Denmark discovered the exoplanet, named Kepler-410A b, orbiting the brightest star in the system.

By studying the star around which the planet revolves, researchers found that the star's rotation appears to be well-aligned with the planetary movement.

The object can be well-studied because the star is relatively bright, it can be seen if strong binoculars are used.

The planet orbits one star of what appears to be a binary star, and the orbit is not circular but slightly eccentric. The planet is a bit larger than our Earth, with a radius of about 2.8 times that of our planet.

With a period of around 18 days, it is much closer to its star than Earth is to our Sun, and therefore unlikely to be suitable for life due to its high temperature.

Perturbations on the discovered planet indicate that there is likely another, as of yet unknown planet in the system, researchers said.

Kepler-410A b has been observed for four years with the Kepler space telescope, a NASA satellite which has monitored the brightness of more than 150,000 stars simultaneously, to look for small regularly-recurring dips in the light, which are indicative of the presence of an exoplanet.

Kepler data has allowed a very detailed study of the host star. On top of that, the star is rather bright; it is in fact the third brightest exoplanet host star discovered by Kepler.

This has allowed the team to study tiny variations in the stellar brightness caused by stellar pulsations, a technique which is called asteroseismology.

"Ultimately, to understand anything about exoplanets, we need to understand the stars they revolve around. In this case, asteroseismology has even allowed us to measure the inclination angle of the star," said Vincent Van Eylen, lead author of the study published in The Astrophysical Journal.

"We now know we are looking at the equator of the star, not at the pole. This can be compared with the orbit of the planet to learn about planetary formation.

"The star is around 2.7 giga-years old and is a little larger than the Sun. We will never be able to go there, as it is located at around 425 lightyears from Earth," Eylen said.