The View From a Distant Star

September 16, 2008 12:26 PM

Take a look at the picture that goes with this blog post.  It may be a piece of history.

Scientists at the University of Toronto say they believe the dot, circled in the upper left, is the first planet ever actually imaged orbiting another star like our Sun.  The star has the prosaic name 1RXS J160929.1-210524, and it’s about 500 light-years from Earth. 

The planet, if that’s what it proves to be, is about eight times as massive as Jupiter (Jupiter, for the record, is about 318 times as massive as Earth), and it’s about 330 times as far from its host star as we are from the Sun.  Details HERE.

It’s probably not a nice place.  It appears to have a temperature of 1,500 degrees C (2,700 deg. F), and if it’s like the (much colder) giant planets in our solar system — Jupiter, Saturn, Uranus, Neptune — it’s probably a gaseous sphere without a solid surface.  The astronomers say they’re also puzzled at how far it is from the star; Neptune, by comparison, is less than a tenth as distant from our Sun.

A few so-called exoplanets have been imaged before, but they were odd cases.  One was circling a brown dwarf, a kind of star without enough mass to keep hydrogen fusion going.  Another was apparently on its own in interstellar space.  Scientists have counted more than 200 exoplanets since the mid-1990s — but without actually seeing them.  Their existence was usually inferred from the little bit of wobble their gravity imposed on their host stars.

The aspiring discoverers, David Lafrenière, Ray Jayawardhana, and Marten H. van Kerkwijk, have submitted their findings to The Astrophysical Journal; you can find the abstract HERE.

They will have to watch their putative planet for a couple of years to make sure it’s actually in orbit, and not just in front of, or behind, the star.  If star and planet move together, this picture could become iconic.  If not, it will just be a footnote. 

(Image courtesy Gemini Observatory, whose Gemini North telescope in Hawaii was used to make the observations.  Adapative optics were used to counteract the distorting effects of the earth’s atmosphere.)