Hovering about 70 light-years from Earth –– that's
"next door" by astronomical standards –– is a star astronomers call
HD 97658, which is almost bright enough to see with the naked eye. But the real
"star" is the planet HD 97658b, not much more than twice the Earth's
diameter and a little less than eight times its mass. HD 97658b is a super-Earth,
a class of planet for which there is no example in our home solar system.
While the discovery of this particular exoplanet is not new,
determining its true size and mass is, thanks to Diana Dragomir, a postdoctoral
astronomer with UC Santa Barbara's Las Cumbres Observatory Global Telescope
(LCOGT). As part of her research, Dragomir looked for transits of this
exoplanet with Canada's Microvariability & Oscillations of Stars (MOST)
space telescope. The telescope was launched in 2003 to a pole-over-pole orbit
about 510 miles high. Dragomir analyzed the data using code written by LCOGT
postdoctoral fellow Jason Eastman. The results were published online today in
the Astrophysical Journal Letters.