New giant planet twice the mass of Jupiter found in Pisces constellation

A team of astronomers has discovered a new giant planet located in a star system within the Pisces constellation.

The planet, perhaps twice the mass of Jupiter, could help researchers led by SF State astronomer Stephen Kane learn more about how extrasolar planets are formed.

The star system harboring the new planet contains only one star, as do the other three systems with extrasolar planets analyzed by Kane, an assistant professor of physics and astronomy, and his colleagues.

It is a surprising finding, given the high rate of multiple-star systems in our solar neighborhood.

"There is a great interest in these stars that are known to host planets," Kane explained, since astronomers suspect that planet formation in a multi-star system would be very different from planet formation in a single-star system like our own.

A multiple-star system "might have not one but two planetary disks" where planets form, he said. "Or it could be that having an extra star would be disruptive, and its gravity could cause any protoplanets to pull apart."

In the case of one star, Pisces' HD 4230, the unexplained radial velocity appears to be coming from the pull of a previously undiscovered giant planet, the researchers report.

They confirmed the planet's presence with additional radial velocity data collected at Hawaii's Keck observatory.

The findings were presented at the annual conference of the American Astronomical Society.