Space.com | Mike Wall | 2010 Aug 02
Astronomers have discovered three small, icy worlds orbiting the sun near Pluto, on the outer reaches of the solar system.
The three newfound bodies are likely big enough to be rounded by their own gravity, which means they may be "dwarf planets" like Pluto, researchers said. Scientists discovered them and eleven other new objects while performing a survey of the Kuiper Belt, the ring of icy bodies beyond Neptune.
"Three of the discoveries would be in the dwarf planet regime," said study lead author Scott Sheppard, of the Carnegie Institution of Washington. "The others were much smaller, and they're probably just irregular chunks of ice or rock." ...
Kuiper Belt Gets New Notches
Scientific American | John Matson | 2011 Aug 08
The map of the solar system may be due for a little updating. A telescopic sky survey has turned up 14 new objects in and around the Kuiper Belt, the icy debris field out past Neptune. [arXiv:1107.5309]
The new trans-Neptunian objects, as they're called, are just the latest to revise our view of the outer solar system. The first Kuiper Belt object was spotted in 1992, but it was not until the middle of the last decade that the belt got its biggest notches. That's when astronomers turned up a handful of large trans-Neptunian objects that led to the creation of the "dwarf planet" category.
Some of the newfound objects may be large enough to qualify as dwarf planets. The key is that they need to be several hundred kilometers across, large enough to have settled into a round shape. So far there are just five confirmed dwarf planets, including the most famous Kuiper Belt object, Pluto. The new potential dwarfs will join several other candidates awaiting confirmation and recognition.
Astronomers will need more detailed observations to determine if any of the newfound objects are truly round. If so, they may be able to slip past the velvet rope and into the exclusive dwarf-planet club.
Three Dwarf-Planet Candidates Found at Solar System’s Edge
Wired Science | Mark Brown | 2011 Aug 09
A new survey of the Kuiper belt — the distant area of the solar system beyond the orbit of Neptune — has turned up three new icy worlds that may be dwarf planets like Pluto.
The frosty Kuiper belt lies roughly 30 to 55 astronomical units (AU) from the Sun. In comparison, the Earth orbits at just 1 AU. Like a frozen asteroid belt, it’s littered with chunks of ice and frozen methane and ammonia.
Scott Sheppard, of the Carnegie Institution of Washington, and a team of astronomers used the 1.3-meter Warsaw Telescope at Las Campanas Observatory in Chile to hunt for objects in previously overlooked areas of the belt, including the southern skies and the galactic plane.
His team sniffed out 14 curious objects. 11 of them are far too small to be considered planetlike, and were probably just regular chunks of ice and rock.
But three of the objects seem to be more than 250 miles wide, which is potentially big enough to be molded into a sphere by their own gravity, and likely qualify them for that oh so prestigious dwarf planet status. ...
Three New "Plutos"? Possible Dwarf Planets Found
National Geographic | Rachel Kaufman | 2011 Aug 11
Three relatively bright space rocks recently found in Pluto's neighborhood may be new members of the dwarf planet family, astronomers say.
The objects were discovered in a little studied section of the Kuiper belt, a region of the solar system that starts beyond the orbit of Neptune and extends 5.1 billion miles (8.2 billion kilometers) from the sun.
Astronomer Scott Sheppard, of the Carnegie Institute of Washington, and colleagues found the bodies using the 1.3-meter Warsaw University Telescope at Las Campanas in Chile.
The region of the Kuiper belt visible from Earth's Northern Hemisphere has been fairly well studied. But until recently, a lack of instruments prohibited searches from the Southern Hemisphere.
The latest survey turned up 14 new Kuiper belt objects, three of which are probably big enough to join Pluto, Eris, Ceres, Haumea, and Makemake in dwarf-planet status, the study authors say. (Related: "Pluto Gets 14 New Neighbors") ...
A Southern Sky and Galactic Plane Survey for Bright Kuiper Belt Objects - S Sheppard et al
- arXiv.org > astro-ph > arXiv:1107.5309 > 26 Jul 2011