On The Trail Of Brown Dwarfs
A report by:
RAdm. RM Wey
COSR: SFS-SFC
As reported in an earlier paper (see osr1221) the 'brown dwarf' is a star that just didn't 'make it'. In order to be a 'star' certain axioms must occur. The first, having a mass of sufficient size (i.e. 75 times that of the planet Jupiter), and second, a core temperature of at least 3 million degrees Kelvin. It was long thought that brown dwarfs were the 'missing link' of celestial objects, this because none had been observed (though such were 'thought' to exist). Many names were 'assigned' to these 'objects' until the name brown dwarf was coined. Some, like black stars or infrared stars come to mind. Even the term 'brown dwarf' is somewhat misleading, as the object actually appears red, not brown. It was in the middle of the last decade of the twentieth century that the 'discovery' of brown dwarfs became a regular occurrence. One of these, GLIESE 229 (osr1221) was detected by both the Palomar Observatory, and the Hubble. Brown dwarfs appear to be more plentiful than was previously believed. Discovery of such objects in the Pleiades Cluster (PPI 15) and the first 'field' brown dwarf (Kelu-1), discovered in 1997, have led astronomers and stellar cartographers to rethink their procedures for the hunt. One such method is referred to as the 'Lithium test'. As stars expend energy, they destroy lithium atoms, this by the continued nuclear reactions within their cores. Because a brown dwarf never reaches the core temperature necessary for such detonations, the element remains forever. Another method of brown dwarf detection is through the Doppler shift. Approximately 10 candidates as brown dwarfs have been detected with this method. It is estimated through the methods being used to date, that there could be approximately 100 billion brown dwarfs in our galaxy alone. The life cycles of ordinary stars and brown dwarfs begin essentially the same; that is to say, that in the early stages, a brown dwarf and a 'star' follows the same pattern. Their formations are the same, beginning with as an interstellar molecular cloud. Over the period of a million years or so, begin to for an accretion disk. Over the next some 10 million years, formations of planets become possible. Yet here is where the divergence begins. Where as a star's mass eventually leads to nuclear detonation, a brown dwarf continues its downward spiral, cooling as it ages. Eventually fading into oblivion. More updates will be provided as they become available.