Billions of Super-Earths with 41% in ‘habitable zone’

Mar 28, 2012
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Billions of Super-Earths with 41% in ‘habitable zone’

Grenoble University is today reporting that their international team of astronomers has taken data they've collected on Super-Earths and figured that additional discoveries could number "in the billions." Over the past few years and the past few months especially, we've been hearing an unbelievable amount of reports of newly-discovered Earth-like planets, this most recent announcement showing that of these "billions" of Super-Earth planets, a whopping 41% sit inside a zone orbiting their stars where they could potentially support life. The HARPS high-precision "Planet Hunter" device works with a 3.6m telescope at the Silla Observatory in Chile to bring us these results today.

HARPS, for those of you that do not know, is an instrument that was, according to those who built it, "built to obtain very high long term radial velocity accuracy (on the order of 1 m/s)." With this instrument being fed information from the telescope at hand, these astronomers have detected a series of 9 planets which, when figured into the greater scheme or things in our galaxy, show great potential.

ABOVE: according to this HARPS team: "Fig. 15. Survey sensitivity derived from the combined phase-averaged detection limits on individual stars. Iso-contours are shown for 1, 10, 20, 30, 40, 50, 60, 70, 80 and 90 stars. Planet detected or confirmed by our survey are reported by red circles and labeled by their names."

Included in this study is a bit of information on what the team has actually discovered and studied intently thus far:

"Our search for planets with HARPS has detected 9 planets
in that sample alone, and a total of 11 planets when counting 2 M dwarfs from another complementary sample. Our detections includes the lowest-mass planet known so far and the first prototype of habitable super-Earths. They are the fruit of slightly less than 500 h of observing time on a 3.6-m telescope, now-days considered as a modest size telescope."

This information comes from the study released today to the Journal Astronomy and Astrophysics - you can read this paper in full here: [eso1214a.pdf] This finding shows its massive potential in a quote from the BBC from team leader Xavier Bonfils from the Observatoire des Sciences de l'Univers de Grenoble, France:

"Our new observations with Harps mean that about 40% of all red dwarf stars have a super-Earth orbiting in the habitable zone where liquid water can exist on the surface of the planet. Because red dwarfs are so common - there are about 160 billion of them in the Milky Way - this leads us to the astonishing result that there are tens of billions of these planets in our galaxy alone" - Bonfils

The paper suggests at one point that super-Earths in the habitable zone exist in 41% of cases within a range of 28% to 95%. The paper of course also lets us know that the study doesn't end here. We'll be checking in with the team here and there to keep you up to date with your upcoming vacation spots light-years away. Stay tuned!

the formation of planets, we need to evaluate the detection efficiency for all mass ranges, which is the purpose of a forthcoming companion paper (Bonfils et al., in prep.)."


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