Washington, Nov 19 : A team of astronomers from Penn State and Nicolaus Copernicus University in Poland has discovered a new planet that is orbiting dangerously close to a red-giant star.
The star, known as HD 102272, which is much older than our own Sun, is being closely orbited by a planet that has a mass that is nearly six times that of Jupiter, the largest planet in our solar system.
The team that discovered the star includes Alexander Wolszczan, the director of the Center for Exoplanets and Habitable Worlds at Penn State University, and Andrzej Niedzielski, who leads his collaborators in Poland.
The team suspects that a second planet may be orbiting HD 102272, as well.
The findings, from the research, shed light on the ways in which aging stars can influence nearby planets.
Scientists already know that stars expand as they age and that they eventually may gobble up adjacent planets.
But, what scientists don't yet understand fully is how aging stars influence nearby planets before they are destroyed.
The team's newly discovered planet is interesting because it is located closer to a red-giant star than any other known planet.
"When red-giant stars expand, they tend to eat up the nearby planets," said Wolszczan. "Although the planet we discovered conceivably could be closer to the star without being harmed by it, there appears to be a zone of avoidance around such stars of about 0.6 astronomical units, which is a little more than half of the distance from the Earth to the Sun," he added.
According to Wolszczan, it is important to find out why planets don't want to get any closer to stars.
"So, one of our next steps is to try to figure out why this zone of avoidance exists and whether it occurs around all red-giant stars," he said.
The team used the Hobby-Eberly Telescope of McDonald Observatory in south-western Texas to make its discovery.
Through the telescope, which is equipped with a precise spectrograph, the scientists observed a pattern of alternating shifts of spectral lines in the light coming from the star, which is located 1,200 light-years from the Earth in the constellation Leo.
The specific pattern of these shifts, which the research team observed, allowed the scientists to determine that one planet, and possibly two planets, orbit the star.
If the second planet exists, the system would become the first multi-planet system discovered around a red-giant star.