Whereas the ejection scenario does predict that brown dwarf disks should be truncated, it is still possible for ejected dwarfs to retain a small disk.
Dust grains in a disk absorb light from the central star or brown dwarf and reemit the energy at longer wavelengths, making objects with disks appear brighter in the infrared than those without.
Researchers differ in some details, but the consensus is that this is probably a brown dwarf.
A brown dwarf found hiding 75 light-years from Earth is the coldest and dimmest ever discovered, a new study reports.
Ground-based radio telescopes, such as the Atacama Large Millimeter Array( ALMA) now under construction in Chile, should be able to probe the outer regions of brown dwarf disks and measure their sizes and masses, thereby testing the formation scenarios much more stringently.
His calculations suggest Nemesis is between 3 to 5 times the mass of Jupiter, rather than the 13 Jupiter masses or greater that some scientists think is a necessary quality of a brown dwarf.
Nicknamed "Nemesis" or "the Death star," this undetected object could be a red or brown dwarf star, or an even darker presence several times the mass of Jupiter.
This diagram shows a brown dwarf in relation to Earth, Jupiter, a low-mass star and the sun.
Cataloged as WISE 1828 + 2650, it lies within 40 light-years of the Sun and is currently the coldest brown dwarf known.
One group, led by John Matese, professor of physics at the University of Louisiana at Lafayette, confirms the notion that it is most likely to be a brown dwarf, a star that never accumulated enough mass to ignite and which has simply sat in space smouldering for billions of years.
The dark star--named Nemesis by astronomers--is thought to be a brown dwarf" that spins round the Sun in an orbit so large it is measured in light years, the distance light travels in a year, equivalent to about 6,000 billion miles.
