NASA's WISE telescope has discovered that there are fewer brown dwarfs in our solar neighborhood than previously thought.
Transcript:Davy Kirkpatrick: Astronomers are interested not only in the bright stars in our neighborhood which are easily seen here around the sun, but also the small, dim objects we can't readily see. Finding these is one of the prime objectives of NASA's Wide-field Infrared Survey Explorer, or WISE.
As we move further away from the sun, we focus only on our neighbors within 26 light years. Within that volume, we increase the brightness of the faintest, reddest stars to make them more easily visible. These objects, known as M dwarfs, are the most common type of star in the solar neighborhood.
Now, viewing from a distance of 30 light years, we circle all the known brown dwarfs: faint objects with too little mass to shine stably as stars do. The blue circles show all of the previously-known brown dwarfs while the red circles show the ones that WISE has identified for the very first time.
This updated census of our solar neighborhood now shows that brown dwarfs are much rarer than stars, there being roughly 6 stars for every known brown dwarf.