Red dwarfs are the smallest and faintest of all stars — so faint that not a single one is visible to the eye alone. Yet they’re also the most common stars. So they’re the targets of several searches for planets.
Red dwarfs would be tough environments for the development of life, though. They’re so feeble that the range of distances where temperatures would be comfortable for life is quite small. The stars produce intense outbursts of X-rays that could destroy a planet’s atmosphere. And at least one red dwarf has been found to fire possible blobs of hot gas.
AU Microscopii is in Microscopium, a faint constellation that’s low in the south at nightfall.
The newborn star is about a third as massive as the Sun. It’s encircled by a disk of dust that could provide the raw materials for making planets.
The blobs are a problem, though. Each one is hundreds of millions of miles across. It may be an explosion of gas from the surface of AU Microscopii.
The blobs are blowing holes in the disk. At the current rate, they could wipe out the entire disk in just one-and-a-half million years. Without the disk, no more planets could take shape. And there would be no comets or asteroids to smack any existing planets — depriving them of sources of water, and perhaps the chemistry of life. So life for a planet — and the development of life itself — might not be easy around a red-dwarf star.
We’ll have more about exoplanets tomorrow.