A triple star system associated with Alpha Centauri is now targeted for a visit by NASA! The triple-star system is composed of a binary system - two stars akin to the Sun --and another, larger and hotter star Called Alpha Centauri A.
Two other stars are smaller, cooler. Alpha Centauri B is itself orbited by a red dwarf and is more distant. A third star may or may not be a part of the "systems". Called Proxima Centauri, it is just 4.22 light-years from Earth --the closest star outside our Solar System. Recall that our own sun is a star.
This is a "big deal" for at least two reasons.
- Alpha Centauri is the closest star system in the sky. Because of that it’s very bright, and because it's very bright, it is well studied. It has been the object of "planet searches" for decades.
- At one time and for awhile some toyed with the idea that the small red dwarf Proxima could boast a planet.
Dopplar Shifts
The signal from the planet is very weak; it was located only because its gravity tugs on the star. The effect of the "tug" is detectable and measurable: it's a wobble! Predictably, a massive star tugs harder on the star it orbits, smaller planets less so. The "wobbles" are very nearly imperceptible. In the case of stars, the "wobble" almost always means: planet!
With planets of "low mass" the doppler shift is less apparent!
Don't Forget the Aliens?
Relatively speaking, the "system" is in our "backyard"! Additionally, the stars seem very much like our own old Sol --the Sun. UFO aficionados have said that this is the most obvious location of "aliens" that some believe have already visited earth. Some believe that one expedition crashed in the planes of South Eastern New Mexico in the 1940's.
Some writers have said that "... we are very close to finding a planet with the same mass as Earth." It is also said that these planets may have water. Liquid water may very well equal life. It is one thing to find planets of the "correct mass". It is quite another to find planets having both ideal position vis a vis "their" star as well as having the "right mass".
Several writers, scientists, astro-physicians have said that it is only a matter of time before the first life sustaining planet other than Earth may be discovered.