Researchers have discovered what might be the universe's smallest star. It might even harbor planets with conditions similar to Earth.
The star in question has been given the unflattering name of EBLM J0555-57Ab and is approximately 600 light-years away from Earth. In terms of size, it is a bit bigger than Saturn. While Saturn is nearly 10 times larger than Earth, stars are normally a lot bigger than planets, so finding a star this small is certainly a rare thing. The study's author noted that, sometimes, finding stars is harder than finding planets.
"This star is smaller, and likely colder than many of the gas giant exoplanets that have so far been identified," said Alexander Boetticher, the study's lead author.
This may very well be as small as a star can possibly be. As most people know, stars are giant clouds of gas that collapse under the force of gravity and give off energy, normally in the form of heat and light. A star does need to maintain a certain amount of mass to begin the process of hydrogen fusion, which both produces energy and ensures that they do not collapse in on themselves.
Anything smaller than the star discovered would likely not be able to produce fusion. Instead, it would likely end up being classified as a brown dwarf. Brown Dwarves are larger than gas giants but are smaller than stars. In terms of light, brown dwarves produce infrared radiation.
This particular star was discovered by the Wide Angle Search for Planets, a collaborative effort of several British universities. It was discovered when researchers noticed its parent star dimming. This was a clue that they were looking at a binary star system.
The Search For Earth-Like Planets
"The smallest stars provide optimal conditions for the discovery of Earth-like planets, and for the remote exploration of their atmospheres," said the study's co-author, Amaury Triaud. "However, before we can study planets, we absolutely need to understand their star; this is fundamental."
Smaller stars are more likely to have planets that contain liquid water, a necessity for the emergence of life. It is unknown whether or not EBLM J0555-57Ab has Earth-like planets, but a similar star known as TRAPPIST-1 is believed to harbor Earth-like planets. This star is believed to have a similar mass to TRAPPIST-1 despite its radius is only a third of the size.