A famous astronomer said that “we certainly can expect for our own Sun which eventually will become a red giant and possibly will consume our Earth”. But we won’t have to worry about it happening, he suggests.

The statement came from Alex Wolszczan, an Evan Pugh Professor of Astronomy and Astrophysics at Penn State University–who in 1992 became the first astronomer ever to discover planets outside our solar system, after a researchers he led discovered new three planets codenamed (1) HD 240237; (2) BD +48 738; and (3)HD 96127, located tens of light years away from our solar system, as it is reported on Penn State’s press release

The new research is expected to shed light on the evolution of planetary systems around dying stars. It also will help astronomers to understand how metal content influences the behavior of dying stars.

The three newly-discovered planetary systems are more evolved than our own solar system.

“Each of the three stars is swelling and has already become a red giant—a dying star that soon will gobble up any planet that happens to be orbiting too close to it,” Wolszczan said. “While we certainly can expect a similar fate for our own Sun, which eventually will become a red giant and possibly will consume our Earth, we won’t have to worry about it happening for another five-billion years.”

Wolszczan also pointed out that, as stars swell to the red-giant stage, planetary orbits change and even intersect, and close-in planets and moons eventually get swallowed and sucked up by the dying star. For this reason, it is possible that HD 240237, BD +48 738, and HD 96127 once might have had more planets in orbit, but that these planets were consumed over time.

“It’s interesting to note that, of these three newly-discovered stars, none has a planet at a distance closer than 0.6 astronomical units—that is, 0.6 the distance of the Earth to our Sun,” Wolszczan said. “It might be that 0.6 is the magic number at which any closer distance spells a planet’s demise.”

Observations of dying stars, their metal content, and how they affect the planets around them could provide clues about the fate of our own solar system.

“Of course, in about five-billion years, our Sun will become a red giant and likely will swallow up the inner planets and the planets’ accompanying moons. However, if we’re still around in, say, one-billion to three-billion years, we might consider taking up residence on Jupiter’s moon, Europa, for the remaining couple billion years before that happens,” Wolszczan said.

“Europa is an icy wasteland and it is certainly not habitable now, but as the Sun continues to heat up and expand, our Earth will become too hot, while at the same time, Europa will melt and may spend a couple billion years in the Goldilocks zone—not to hot, not to- old, covered by vast, beautiful oceans.”

The research will be published in December in the Astrophysical Journal. The first author of the paper is Sara Gettel, a graduate student from Penn State’s Department of Astronomy and Astrophysics, and the paper is co-authored by three graduate students from Poland. Funding for this research was provided by NASA and the Polish Ministry of Science and Higher Education.

Penn State’s Center for Exoplanets and Habitable Worlds is organizing a conference in January 2012 to discuss planets and their dying stars. The conference will be held in Puerto Rico and is scheduled to take place at exactly 20 years from when Wolszczan used the 1,000-foot Arecibo radiotelescope to detect three planets orbiting a rapidly spinning neutron star—the very first discovery of planets outside our solar system.

(Disclosure: Adapted from a press release written by Katrina Voss, titled “Three New Planets and a Mystery Object Discovered Outside Our Solar System” published at Penn State University, Eberly College Science)