When the gringa’s dear readers think of a star, what do you think of? The Sun? Polaris? Alpha Centauri? And what do you think would happen if you reached out to touch the Sun? You’d probably get vaporized, right? Well, depending on the star, not necessarily. In fact, if you touched the right star it might be a sensation more like when you roll over in bed and find the cool spot.
Brown dwarfs are cold stars. There are 14 that NASA believes are cool enough to touch. Cool! They are also the oldest stars in the Universe. I guess stars are kind of like people. Old folks with poor circulation are generally cold all the time. Stars get old and cold, too. Out of all the old, cold, brown dwarf stars in the Universe, it’s the Y-dwarfs that are even cooler than the average human’s body temperature. Y, you may ask. Well, the gringa will tell you why the Y is the way that it is.
Not only are they old but they are failures. Poor Y-dwarfs. They must have very low self-esteem. Perhaps that is why they don’t shine as brightly as other stars. They have grown old and are failures as stars. The gringa feels very sorry for the poor, little things.
Because their cores are not very dense they can’t fuse loads of atoms within. That means they don’t burn as hot and brightly as other stars. The gringa finds it very amusing that the denser a star is the brighter it is. It doesn’t seem to work that way in humans.
If Y-dwarfs are such failures at being stars, the gringa wonders if they should be considered stars at all. Do we have a Pluto prospect in the future? Just as Pluto got demoted from planet to dwarf planet, Y-dwarf stars may very well face the possibility of being re-classified. In the future scientists may decide they don’t meet all the guidelines of being a star. The gringa thinks this is a wonderful possibility for Y-dwarfs. Whereas poor Pluto suffered a demotion, the Y-dwarf could get better news. They could go from being failures as stars to being over-achievers for whatever it is they may become!
However, it may take astronomers quite some time to collect enough data in their studies. Their failure to shine bright like a diamond in the sky means it is difficult to view and study them. It’s practically impossible to study them at all with a telescope dependent on visible light. To take productive peeks at Y-dwarfs NASA had to construct an infrared telescope and mount it to an orbiting satellite. And that is why the Universe is wiser thanks to these cold, little star failures, because of Wide-field Infrared Survey Explore (WISE) that studies them in the heavens.
Image Credit: www.jpl.nasa.gov