Astronomers spy nursery of baby exoplanets

Today, at the Extreme Solar Systems III conference in Waikoloa Beach, Hawaii, astronomers announced the discovery of at least one, probably two, baby Jupiter-like planets still actively forming and surrounded by their natal clouds of gas and dust. The Gemini Planet Imager at the Gemini South telescope in Chile provided the key data for this discovery. The system resembles an infant version of the first directly imaged multiple planet system discovered using the Gemini North telescope on Maunakea.

Astronomers report that this system, surrounding a star known as HD 100546, is giving us a glimpse back in time to see what other more developed exoplanet systems looked like in their adolescence. The star is remarkably similar to HR 8799, the first multiple planet system directly imaged and discovered in 2008, but HR 8799’s planets are fully formed. “Now, seven years later, we can for the first time see what this planetary system may have looked like while the planets were just coming into existence,” said Thayne Currie from the Subaru Observatory in Hilo, Hawaii.

The team expects many more discoveries as they probe the environs of HD 100546 more deeply. According to Ryan Cloutier from the University of Toronto, systems like this one, containing multiple forming giant planets, have extensive spiral arms in their disks. “For HD 100546, its spiral arms may suggest the presence of additional planets,” said Cloutier. “In fact, one of the observed protoplanets might instead be a hotspot within the disk or a signpost of an unseen protoplanet.”

The unique set of data for this research, including high-contrast direct imaging, integral-field spectroscopy, and polarimetry, “really brought this system into focus — it’s remarkably powerful,” said Carol Grady from NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

GPI is now in its second year of regular observations at the Gemini South telescope, and in addition to general observations for the astronomical community like those that produced this result, the ambitious Gemini Planet Imager Exoplanet Survey (GPIES) has over a year of observations completed.