Exoplanet orbiting solar twin found in distant star cluster

Zee Media Bureau\Philaso G Kaping

New Delhi: Astronomers have discovered an exoplanet orbiting a solar twin 2500 light-years away, according to a new study.

The study, led by Anna Brucalassi from the Max Planck Institute for Extraterrestrial Physics, found three exoplanets in a star cluster of about 500 stars in the constellation of Cancer. More than one thousand exoplanets have been found so far but only a handful have been found in star clusters. That rarity prompted experts to wonder if there was something in star clusters that disrupted the formation of planets from clumps of dust and gas.

"In the Messier 67 star cluster the stars are all about the same age and composition as the Sun. This makes it a perfect laboratory to study how many planets form in such a crowded environment, and whether they form mostly around more massive or less massive stars," said Brucalassi.

Using ESO`s HARPS telescope in Chile and assisted by several other observatories worldwide, astronomers monitored 88 selected stars in Messier 67 over a period of six years to look for movements of the stars indicating the presence of planets in their midsts. The first of these three exoplanets is orbiting a star almost identical to our Sun.

But it orbits at such close proximity that the temperature would be scorching. Water, the stuff of life as we know it, could not exist in liquid form.

Luca Pasquini, co-author of the study, from ESO added: "These new results show that planets in open star clusters are about as common as they are around isolated stars, but they are not easy to detect."

"The new results are in contrast to earlier work that failed to find cluster planets, but agrees with some other more recent observations. We are continuing to observe this cluster to find how stars with and without planets differ in mass and chemical makeup."
(With Agency inputs)