Hunt for Alien, Earth-Sized Planets Helped by Stellar Alignment of Proxima Centauri

The hunt for alien planets is on. NASA's Hubble Space Telescope will have two opportunities in the next few years to look for Earth-sized planets around the red dwarf Proxima Centauri. The findings could allow scientists to learn a bit more about other planets and, in turn, learn a bit more about Earth as well.

Proxima Centauri is the star nearest to our own Sun. In October 2014 and February 2016, the star will pass in front of two other stars, which will allow astronomers to get a better view of planets that are possibly orbiting Proxima Centauri.

The star is actually a red dwarf, which is the most common class of stars in our Milky Way galaxy. For every one star like our Sun, there are about ten red dwarfs. Part of the three-star Alpha Centauri system, the star is located in the closest solar system to our own.  Since red dwarfs are less massive than other stars, they tend to have smaller planets; this means that they're ideal for finding Earth-sized planets. Already, researchers have detected a hot rocky exoplanet roughly the size of Earth circling Alpha Centauri B, another star in the same system as Proxima Centauri, according to Space.com.

In the past, researchers have been unable to detect planets around Proxima Centauri. However, astronomers believe they can get around the difficulties of detecting planets by looking for microlensing effects during the two stellar alignments occurring soon.

Microlensing occurs when a foreground star passes close to our line of sight to a more distant background star. These images of the background star may be distorted, brightened and multiplied depending on the alignment between the foreground lens and the background source. Although these microlensing events range from just a few hours to a few days, they should allow astronomers to see any Earth-like planets orbiting Proxima Centauri.

Since the red dwarf is so close to Earth, the area of sky warped by its gravitational field is larger than for more distant stars. This makes it easier to look for shifts in apparent stellar position. However, the position shifts will be too small to be seen by any but the most sensitive telescopes in space and on the ground, which means that astronomers will have to keep their instruments ready.

Currently, researchers are waiting for the alignment to occur. When it does, they could learn quite a bit more about the red dwarf star and any planets it might possess.