ESO Astronomers Directly Image Lightest Exoplanet Yet

For anyone with even a passing interest in the night sky, there has probably never been a better time to be alive.  Almost weekly, we are learning more and more about the worlds which surround us, a fact underscored last week when radar imaged  passing Near Earth Asteroid 1998 QE2 complete with its own tiny “moon.”

One of the most exciting aspects of the current era is the rate at which new worlds beyond our own solar system are  being added to the catalogue of that which is known about the universe around us.  Among the different ways new planets are being discovered, the most productive method so far is that employed by the now hobbled Kepler Space Telescope,  observing the tiny dip in a star’s light as planet passes in front of it, known as the transiting method.  Another technique,  the radial velocity method,  detects planets by recording the infinitesimal wobble in star’s rotation caused by a planet orbiting it.  The third way,  observing the planet directly, is perhaps the most gratifying, but it is also the most difficult.  Among the roughly 1,000 planets discovered to date, only 12 have been imaged directly, all of which are understandably on the large side of the spectrum.

Now, a team at the European Southern Observatory using the Very Large Telescope, has directly imaged the lightest planet yet “seen,” orbiting a very young star 300 light years away. The star HD 95086 is in the constellation Carina, (remember its the European Southern Observatory)  and the planet is estimated to be 4 to 5 times the mass of Jupiter.  The newfound world orbits far out from its sun,  at nearly twice distance of Neptune’s orbit,  which is what makes it possible to distinguish the planet’s reflection apart from the much brighter light coming from star HD 95086.  Between the planet and the star lies the primordial debris disc  from which it formed,  and  which is likely still a nursery for other planets just now being born.  The full story can be found at the ESO website.