NASA Discovers Stars That Are Cool To The Touch. Well Done, Universe.

The Universe never fails to impress me. On the almost daily tip. Today we have cold  stars. NASA has identified stars, called  Y-dwarfs that are colder than the human body.

io9:

Last year, NASA announced that it had discovered 14 of the coldest stars it had ever recorded. The so-called “brown dwarfs” were, at that time, listed among the coldest known stars in our universe.

Now, employing the same instrumentation it used to detect last year’s brown dwarfs, NASA has identified six new, even-cooler orbs known as “Y-dwarfs.” Y-dwarfs are the coldest members of the brown dwarf family, which makes these stars the coolest of the cool. How cool you ask? Try cooler than the human body.

Brown dwarfs, and Y-dwarfs especially, are what astronomers often refer to as “failed stars;” the low density of these astral bodies prohibits them from fusing atoms at their cores, which in turn keeps them from burning with the enduring heat and intensity typical of other stars (our Sun, for example, has a surface temperature of around 10,000 Fahrenheit, a core temperature as high as 27 million degrees Fahrenheit, and will continue to burn for at least a few billion years).

But astronomers can still learn a lot from these stellar failures, so it’s in their best interests to catalog as many of them as possible. Unfortunately, the same characteristics that make these brown dwarfs interesting to study makes them very difficult to find.

Because brown dwarfs lack the mass to keep burning for extended periods of time, they tend to gradually cool and fade, until the only light they emit is found at infrared wavelengths that are invisible to the human eye. In other words, searching for brown dwarfs with a visible-light telescope is damn near impossible.

Très chouette.