A planet with about the same mass as Earth
has been discovered in orbit around Alpha Centauri B, a star in the Alpha Centauri triple star system - the solar system's closest neighbor, a mere 4.3 light years away. Alpha Centauri B is very similar to the Sun, and this marks the first planet with a mass similar to Earth ever found around a Sun-like star. However, the planet is orbiting at a distance of about six million kilometers, much closer than Mercury is to the Sun in the Solar System, so temperatures above 400 degrees Celsius may make vacationing there unpalatable even for the most dedicated beach-goer. However, lead paper author Xavier Dumusque called it "a major step towards the detection of a twin Earth in the immediate vicinity of the Sun."
posted by kyrademon
on Oct 16, 2012 -
A direct detection of a brown dwarf
only 12.7 light years away (practically next door in interstellar terms)
adds another substellar object to the list of those relatively close by. While not quite the closest such object yet detected,
it’s notable for being pinpointed with a combination of ground-based adaptive optics
and Simultaneous Differential Imaging,
a special set of filters designed to subtract out starlight while leaving the light from substellar objects. This could be an important milestone in the ongoing quest to directly detect extrasolar planets,
as opposed to finding their traces indirectly via methods such as stellar wobble or gravitational microlensing.
Direct detection, among other things, makes it much easier to analyze planetary atmospheres for traces of life.
An object that could be as small as 9 Jupiter masses, less than 13 light years away, is a heck of a good step forward, especially considering that the very first indirect detections of extrasolar planets weren't made until the 1990’s,
and I recall serious arguments being made in the 1980’s that they did not, in fact, exist.
posted by kyrademon
on Mar 22, 2006 -