February 27, 2015

Astronomers using data from NASA's Wide-field Infrared Survey Explorer, or WISE, have found a cluster of stars forming at the very edge of our Milky Way galaxy.

"A stellar nursery in what seems to be the middle of nowhere is quite surprising," said Peter Eisenhardt, the project scientist for the WISE mission at NASA's Jet Propulsion Laboratory in Pasadena, California. "But surprises turn up when you look everywhere, as the WISE survey did."

The discovery, led by Denilso Camargo of the Federal University of Rio Grande do Sul in Porto Alegre, Brazil, appears in a new study in the journal Monthly Notices of the Royal Astronomical Society.

The Milky Way, the galaxy we live in, has a barred spiral shape, with arms of stars, gas and dust winding out from a central bar. Viewed from the side, the galaxy would appear relatively flat, with most of the material in a disk and the central regions.

Using infrared survey images from WISE, the team discovered two clusters of stars thousands of light-years below the galactic disk. The stars live in dense clumps of gas called giant molecular clouds.

This is the first time astronomers have found stars being born in such a remote location. Clouds of star-forming material at very high latitudes away from the galactic plane are rare and, in general, are not expected to form stars.

"Our work shows that the space around the galaxy is a lot less empty that we thought," said Camargo. "The new clusters of stars are truly exotic. In a few million years, any inhabitants of planets around the stars will have a grand view of the outside of the Milky Way, something no human being will probably ever experience."