A sun-like star some 127 light years away may harbor a record number of planets, nine, spotted in another solar system.
Our own solar system only possesses eight planets, with the recent demotion of Pluto to dwarf planet status by astronomers.
HD 10180 planetary system (Artist’s Impression) Credit: ESO
Accepted for publication by the journal Astronomy and Astrophysics, the report by astronomer Mikko Tuomi of the United Kingdom’s University of Hertfordshire, looks at HD 10180, an often-examined star in the constellation of Hydrus, the water snake.
In 2010, European Southern Observatory astronomers reported the solar system likely hosted 7 planets, nearly as many as our own, one of them perhaps only 1.4 times heavier than Earth, making it among the smallest worlds detected outside our solar system (a so-called “Super-Earth” planet). But in the new study, Tuomi subjects the ESO telescope team’s data to further scrutiny, and reports evidence for two more planets.
View of the sky around the star HD 10180 (center). Credit: ESO
One weighs in at 1.9 times heavier than Earth and the other at about 5.1 times heavier than Earth, “enabling the classification of them as super-Earths,” says the study. The two newly-discovered planets follow hot orbits, circling their star in under 10 days for the small one, and 68 days for the larger.
“… the star is a very quiet one without clear activity-induced periodicities, which makes it unlikely that one or some of the periodic signals in the data were caused by stellar phenomena. Also, the periodicities we report, namely 9.66 and 67.6 days, do not coincide with any periodicities arising from the movement of the bodies in the Solar system. Therefore, we consider the interpretation of these two new signals of being of planetary origin to be the most credible explanation,” says the study.
If the observation proves out, then HD 10180 would be the record-holding solar system, so far, for number of planets, Tuomi concludes. Stay tuned, though, as planet detection is a fast-moving field.