According to a paper submitted for publication, astronomers have discovered that two previously observed objects at the outer edge of our solar system are actually pairs. These "trans-Neptunian objects" orbit the sun as part of the Kuiper belt.

The binary nature of the objects were discovered by the Hubble Space Telescope. Previously disovered trans-Neptunian objects 1997 CQ29 and 2000 CF105 were observed by Hubble's WFPC2 (Wide Field Planetary Camera).

According to an abstract of the research paper "The two components of 1997 CQ29 were separated in our images by 0.20 arcsec in November 2001 and by 0.33 arcsec in June/July 2002. The corresponding minimum physical distances are 6100 km and 10,200 km. The companion to 2000 CF105 was 0.78 arcsec from the primary, at least 23,400 km."

Pluto and its moon Charon are the most famous inhabitants of this region of the solar system. They also form a binary pair. In addition to Pluto and Charon, five other binary pairs were already identified. Recent observations of 1997 CQ29 and 2000 CF105 raises the tally of known binary trans-Neptunian pairs to eight.

According to the paper: "binarity appears to be a not-uncommon characteristic in this region of the solar system, with detectable companions present in 4% of the objects we have examined."

Related Links

• Detection of Two Binary Trans-Neptunian Objects, 1997 CQ29 and 2000 CF105, with the Hubble Space Telescope
• List Of Transneptunian Objects

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