J. Davy Kirkpatrick is an American astronomer at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, California. Kirkpatrick's research was named one of the top ten science accomplishments of the first ten years (1992–2002) of the W. M. Keck Observatory and one of the Top 100 Stories of 2011 by Discover Magazine.
J. Davy Kirkpatrick
Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main-sequence stars. Their mass is approximately 13 to 80 times that of Jupiter (MJ)—not big enough to sustain nuclear fusion of ordinary hydrogen (1H) into helium in their cores, but massive enough to emit some light and heat from the fusion of deuterium (2H). The most massive ones can fuse lithium (7Li).
Artist's concept of a T-type brown dwarf
The smaller object is Gliese 229B, about 20 to 50 times the mass of Jupiter, orbiting the star Gliese 229. It is in the constellation Lepus, about 19 light-years from Earth.
Planets, brown dwarfs, stars (not to scale)
A size comparison between the Sun, a young sub-brown dwarf, and Jupiter. As the sub-brown dwarf ages, it will gradually cool and shrink.