Astronomers discover closest super-Earth

While it orbits too close to the star to be hospitable, its proximity to the star makes it an ideal target for future studies of its atmosphere, if it has one.

The finding was enabled by the HARPS-N spectrograph which is located with the Italian Telescopio Nazionale Galileo in the Roque de los Muchachos Observatory.

Unfortunately HD 219134b is not habitable. It’s only 21 light years away.

Astronomers from the University of Geneva (UNIGE) and members of the NCCR PlanetS say that the cortege of planets around HD219134 is composed of three mostly rocky super-Earths and an outer giant planet, a configuration reminiscent of our own Solar System. By watching for subtle shifts in the light, it is possible to determine the orbit of any planets in the star system. The planet as it passes in front of the star causes a decrease in brightness. The method of discovery is called radial velocity technique, “in which a planet’s mass and orbit can be measured by the tug it exerts on its host star”, according to NASA.

The Spitzer Space Telescope. With these sorts of observations, scientists are coming to a better understanding. The Verge reports that one orbits the star every 6.8 days, is 2.7 times as large as the Earth, and the other has a 47-day orbit as well as being 9 times the size of Earth. It is being dubbed “Super Earth” by some. This suggests a rocky composition and sees it classed as a super-Earth.

The Spitzer Space Telescope is part of NASA’s Great Observatories Program, designed to detect infrared (heat) radiation from cosmic regions hidden from optical telescopes. With its supply of liquid helium long since exhausted, Spitzer continues operating under the Warm Mission program using two remaining on-board instruments. It’s one of the closest exoplanets ever discovered, and the closest confirmed rocky world we know about. HD219134b: A transiting rocky planet in a multi-planet system at 6.5 pc from the Sunday. It’s much larger than Earth, it’s rocky (or with solid surfaces), but cannot sustain life because it’s too close to its host star (or not orbiting within the so-called goldilocks zone). It can be seen near the North Star’s area, specifically the Cassiopeia constellation. “To do this, we needed to go to space to reach the required precision”, said Ati Motalebi, the study’s first author. “It can be considered a kind of Rosetta Stone for the study of super-Earths“, Michael Gillon, the lead scientist for the Spitzer detection, said in the announcement.

If you were on a spaceship going this fast, it would take you just over 387,000 years to get to HD 219134b from Earth.