Robotic telescope that is scanning the sky every night at Lick Observatory in USA discovered three planets, supersized Earths, around a nearby star. These planets are seven to eight times the mass of Earth and orbit very close to their host star. Scientists hope that telescope will continue hunting for super-Earths and Earth-size planets, because even relatively near systems have not been fully described yet.
Three newly discovered planets orbit their star at a distance closer than Mercury orbits the sun, completing their orbits in just five, 15 and 24 days. The star itself is 54 light-years distant from the Earth, which is close enough to consider it part of Earth’s neighbourhood. Such planets are not easy to find, but the robotic telescope provides a lot of help for scientists.
Lauren Weiss, who works with the telescope, said that these planets are nothing like we can find in our Solar system and they were discovered thanks to relatively new telescope. The robotic telescope, called Automated Planet Finder, is mounted on top of Mt. Hamilton near San Jose. It was specifically created to search for planets similar to Earth. It is said that robotic telescopes that help scientists scan the sky will be the way we discover planets in the future.
Up until now most of the planets discovered outside of our Solar system were much more massive than these. Usually they are about the size of Neptune — 17 times the mass of Earth or even larger. Majority of them are gas giants like Jupiter. New discoveries demonstrate abilities of Automated Planet Finder to find low-mass planets around nearby stars. Some of these planets that this telescope is designed to look for might have temperatures and surface conditions suitable for life.
Such planets are very difficult to find and are invisible to the naked eye. They only announce about their existence by creating a slight wobble in their host star. This phenomenon is detected by the Doppler technique pioneered by Lauren Weiss’s adviser, Berkeley professor of astronomy Geoff Marcy. The innovative telescope speed up the process of finding such low-mass planets, however, it was not robotic at first.
Initially scientists used it as a conventional telescope, staying old night going from star to star, looking for planets. But later they decided that computer could take the shift too, which was very appealing idea for sleep-deprived scientists. They wrote software that allowed computer to replace them for searching for exoplanets.
The evidence that there might be planets orbiting star code named HD 7924 were found by W.M Keck Observatory in Hawaii back in 2009. However, it took five years of additional work in Keck Observatory and year-and-a-half campaign by the Automated Planet Finder to find additional planets orbiting the star. The planets pinpointed by the APF were confirmed via the Keck Observatory and the Automatic Photometric Telescope at Fairborn Observatory in Arizona.
Scientists say that new level of automation in astronomy is a game-changer and compared it with a driverless car that goes planet-shopping. It will speed up exploration of the space and can broaden our view of the neighbouring systems very effectively. Observations of HD 7924 are part of the new survey for super-Earth planets orbiting nearby stars. When it is complete we will have a census of small planets orbiting sun-like stars within approximately 100 light-years of Earth. However, we will have to wait and see what automation of astronomy will bring next, because now discoveries should be made quicker.