The Top 10 Everything of 2009

In December, an international team of astronomers announced it had spotted a planetlike object orbiting a star much like our sun. The star lies 300 trillion miles, or about 50 light-years, from Earth; the planetlike object is estimated to be 10 to 40 times the size of Jupiter. Using a new planet-hunting instrument on the Subaru telescope in Hawaii, scientists were able to get direct images of this new object — which may or may not be a brown dwarf (a failed star). Although direct images of other solar systems have been taken before, this is the first time astronomers have captured a star this similar to the sun in size and temperature. Scientists say the real surprise is the location of the orbit of GJ 758 B, as the newly identified object was dubbed: it was previously thought that large planets form either closer to or farther from their stars, but not in the location of GJ 758 B, which is about as far from its star as Neptune is from the sun. Alan Boss, an astronomer at the Carnegie Institute for Science who was not involved in the research, said the "beautiful detection of a very low-mass companion to a sunlike star reminds us again how little we truly know" about the planets around nearby stars.