A Planet-like Companion Growing up in the Fast Lane
The cliché that youth grow up so fast is about to take on a new twist. This is due to the discovery of a very young planet-like object (with a mass somewhere between 5-10 times that of Jupiter), paired with a low-mass brown dwarf. What is unique about this system is that the planet-like body appears to have formed in about a million years - more rapidly than some theories of planet formation predict. Kamen Todorov of Pennsylvania State University and co-investigators made the discovery using the keen visible-light eyesight of the Hubble Space Telescope combined with high-resolution adaptive optics infrared images from the Gemini Observatory. The images of the pair were obtained as part of a survey of 32 young brown dwarfs in the Taurus star-forming region located some 450 light years away. The team's paper is in press for an upcoming issue of the Astrophysical Journal Letters. Identified as 2M044144, the primary brown dwarf is likely about 20 times the mass of Jupiter and separated from the smaller body by about 3.6 billion kilometres - for comparison, Saturn is about 2.25 billion kilometres from the Sun. Read more
As our telescopes grow more powerful, astronomers are uncovering objects that defy conventional wisdom. This latest example is the discovery of a planet-like object circling a brown dwarf. It's the right size for a planet, estimated to be 5-10 times the mass of Jupiter. There has been a lot of discussion in the context of the Pluto debate over how small an object can be and still be called a planet. This new observation addresses the question at the other end of the size spectrum: How small can an object be and still be a brown dwarf rather than a planet? This new companion is within the range of masses observed for planets around stars - less than 15 Jupiter masses. But should it be called a planet? The answer is strongly connected to the mechanism by which the companion most likely formed. What's even more puzzling is that the object formed in just 1 million years, a very short time to make a planet according to conventional theory. Read more
Mysterious planet-like object reveals its surprising identity
A mysterious planet-like object orbiting a not-quite-starlike "brown dwarf" is the most recent enigma discovered by astronomers with their ever-more powerful telescopes. Kamen Todorov, a graduate student at Penn State University, and a team of co-investigators including Kevin Luhman, assistant professor of astronomy and astrophysics at Penn State, used the keen eyesight of the Hubble Space Telescope and the Gemini observatory to directly image the planet-like object. The team's discovery, which resulted from a survey of 32 brown dwarfs in the Taurus star-forming region, will be published in the Astrophysical Journal. Read more