The discovery of Gliese 887's super-Earths opens up excellent opportunities for future studies of such planets in the search for extraterrestrial life.
"The exciting thing about these planets are that they orbit a star so close to the Sun, and so very bright", said UNSW-based planet hunter Prof Chris Tinney, who is a co-author on the paper. Both of them are close to the habitable zone of the system, which is actually closer to the star compared to the zone where the Earth is because Gliese 887 is smaller and dimmer than the Sun.
Itself star Gliese 887 fairly quiet, like a red dwarf.
The research, which was published in Science, holds a lot of promise, but we don't yet possess the technology to view these Earth-alikes in greater detail. The nearest star to the Sun - Proxima Centauri - is an example of a red dwarf.
The team monitored the system using the Radial High Speed Planet Finder (HARPS) spectrograph from the European Southern Observatory of Chile and analyzed almost 20 years of archival data in Gliese 887.
Apart from discovering the nearby super-Earths, the researchers also found that Gliese 887 has very few sunspots, which means that it is not as active as the Sun and would therefore not sweep away the super-Earths' atmospheres. However, scientists said the temperature of the later planet is about 70 degrees Celsius, or 158 degrees Fahrenheit.
Regular signals detected indicate the presence of two planets, super-Earths to be specific -Gliese 887b and Gliese 887c - with orbiting periods of 9.3 and 21.8 days. A study led by the University of Göttingen reports the discovery of a system of super-Earth planets orbiting nearby of red dwarf Gliese 887 or GJ 887 and may possibly possess conditions that can harbor life.
"So given the star is relatively inactive the newly discovered planets could be expected to retain their atmospheres". Additionally, the researchers also found that the brightness from the red dwarf star is nearly constant, making it easier for space telescopes to look for the atmospheres on the super-Earths.
This makes it a prime target for the James Webb Space Telescope, a successor to the Hubble Telescope that is due to launch in the next year. At the same time, the team also observed a single jiggle, of a potential planet making a 50-day orbit in the star's temperate zone. Planets tend to orbit these stars so closely, putting them in range of intense solar flares and radiation. However, the more distant location of the unconfirmed third planet may place it within GJ 887's so-called "habitable zone".
The star Gliese 887 is the best near us to study the atmospheres of its exoplanets since it is a bright and peaceful celestial body.