Graham et al. via Swinburne
The "emerald-cut galaxy" known as LEDA 074886 lies 70 million light-years away. This false-color image was taken with the Subaru Telescope's Suprime-Cam. The contrast has been adjusted to reveal the rapidly spinning disk of material at the galaxy's core.
Astronomers puzzle over square galaxy
We have the Hexagon on Saturn, the Red Rectangle nebula — and now there's a square-shaped galaxyfor astronomers to deal with.
"It's one of those things that just makes you smile because it shouldn't exist, or rather, you don't expect it to exist," Alister Graham, a professor at Australia's Swinburne University of Technology, said this week in a news release. "It's a little like the precarious Leaning Tower of Pisa, or the discovery of some exotic new species which at first glance appears to defy the
And yet, there it is: LEDA 074886, a square-looking dwarf galaxy that's part of the NGC 1407 Group of more than 250 galaxies in the constellation Eridanus, 70 million light-years away. The "emerald-cut galaxy" was spotted in a wide-fieldimage taken using Japan's Subaru Telescope, and discussed in a research paperto be published in The Astrophysical Journal.
Most galaxies are either spheroidal, disk-shaped or irregular and lumpy, Graham noted. LEDA 074886 seems to have four rounded corners. Graham and his colleagues suspect that the galaxy is actually shaped like a shallow cylinder or an inflated disk, seen somewhat side-on. That would fit with observations from the Keck Telescope, which picked up the signs of a rapidly spinning, thin disk embedded in the galaxy's center.
"One possibility is that the galaxy may have formed out of the collision of two spiral galaxies," said Swinburne Professor Duncan Forbes, one of the study's co-authors. "While the pre-existing stars from the initial galaxies were strewn to large orbits, creating the emerald-cut shape, the gas sank to the midplane, where it condensed to form new stars and the disk that we have observed."
Studying the dynamics behind the square-looking shape could provide insights for modeling the development and interaction of other galaxies in collision, the researchers said.
"Curiously, if the orientation was just right, when our own disk-shaped galaxy collides with the disk-shaped Andromeda galaxy, about 3 billion years from now, we may find ourselves the inhabitants of a square-looking galaxy," Graham said. Maybe Huey Lewis was right: It's hip to be square.
Where in the Cosmos?
Three Cosmic Log correspondents were definitely hip to the square-shaped galaxy: The Subaru Telescope's view of the galaxy served as this week's "Where in the Cosmos" picture puzzle on theCosmic Log Facebook page, and it took Paul Burley, Karl J. Martin and Charles Britten less than three minutes to come up with the answer.
Three Cosmic Log correspondents were definitely hip to the square-shaped galaxy: The Subaru Telescope's view of the galaxy served as this week's "Where in the Cosmos" picture puzzle on theCosmic Log Facebook page, and it took Paul Burley, Karl J. Martin and Charles Britten less than three minutes to come up with the answer.
The fact that Paul provided the geometrical answer first is particularly fitting, because he's the author of a book about cosmic geometry titled "The Sacred Sphere: Exploring Sacred Concepts and Cosmic Consciousness Through Universal Symbolism."
