These are *not* the smallest exoplanets found yet. That honor goes to the pulsar planets that were discovered in the early 1990′s. Their maximum masses derived from radial velocity were near or well below the mass of Earth, including this one:

http://en.wikipedia.org/wiki/PSR_B1257%2B12_A

Which is, in fact, the smallest exoplanet ever discovered (in 1994), weighing in at only twice the mass of Earth’s *Moon*, making it much smaller than all other exoplanets discovered so far, and in fact smaller than any of the 8 planets in our solar system.

I do occasionally see articles that give a nod to this by adding “around any main-sequence star” after “smallest yet discovered,” which is at least technically accurate.

It seems like a disservice to those early planet hunters to always overlook that achievement, especially because most articles on exoplanets also indicate the “first” exoplanet discovered was 51 Pegasi b in 1995, which is also completely untrue.

Second, it shows that red dwarf stars can form and hold onto planets… which itself is important because red dwarfs are by far the most common kind of star in the Universe. They make up roughly 80% of the total number of stars!

Plus while they used to be considered unlikely hosts for habitable planets as Ken Croswell points out here :

http://kencroswell.com/HowRedDwarfsProtectTheirPlanets.html

& here :

http://kencroswell.com/reddwarflife.html

Red dwarfs may be a lot better suited to hosting life than we used to think.

Mind you, coping with red dwarf flares – and many of them really do flare dramatically – could present life on planets necessarily tucked in close with some major issues. As kaler notes on page 31, “The Faintest Stars” article by James B. Kaler , in ‘Astronomy’magazine, August, 1991 :

“Imagine M-dwarf [red dwarf - ed.] bathing on the beach and having your star suddenly -with no warning at all – become ten times brighter.”

Yikes!

Can anyone imagine our Sun becoming even twice as bright abruptly?

As always, there’s just so much still to learn.

Wondering more than ever before if the nearer red dwarf stars – eg. Proxima Centauri, Barnard’s Star, Wolf 359 – have planets, what they’re like and when, if ever, we’ll know? A twin of Barnard’s Star eh?

Ah, for FTL travel, sigh.

The more of these newly-detected planets we catalog, the less appropriate it will be to use distinct terminology. From a scientific standpoint, what justifies a vocabulary for discussing planetary bodies which implicitly views the ones in our own system as somehow inherently special or different?

Possible Disintegrating Short-Period Super-Mercury Orbiting KIC 12557548

The exoplanet low mass limbo just keeps getting lower!

Down to the mass of Mars – wow.

Surely we must be pushing the limit of what they can detect now – but does have me wondering how much lower (mass~wise) they can go. All the way to Pluto-mass & beyond? Also wonder if further study could use perturbations of these rock dwarfs to detect any higher (or even equally low) planets further out?