THE newfound gas-giant planet TrES-2b is black with a slight red glow, experts estimate.
It may be hard to imagine a planet
blacker than coal, but that’s what
astronomers say they’ve discovered in our home galaxy with NASA’s Kepler space telescope.
Orbiting only about three million miles out
from its star, the Jupiter-size gas giant
planet, dubbed TrES-2b, is heated to 1,800
degrees Fahrenheit (980 degrees Celsius).
Yet the apparently inky world appears to
reflect almost none of the starlight that
shines on it, according to a new study.
“Being less reflective than coal or even the
blackest acrylic paint—this makes it by far the darkest planet ever discovered,” lead study author David Kipping said.
“If we could see it up close it would look like a near-black ball of gas, with a slight glowing red tinge to it—a true exotic amongst exoplanets,” added Kipping, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
NASA’s Planet Detector
The Earth-orbiting Kepler spacecraft was
specifically designed to find planets outside
our solar system. But at such distances—
TrES-2b, for instance, is 750 light-years
from us—it’s not as simple as snapping
pictures of alien worlds.
Instead, Kepler—using light sensors called
photometers that continuously monitor tens of thousands of stars—looks for the regular dimming of stars.
Such dips in stellar brightness may indicate that a planet is transiting, or passing in front of a star, relative to Earth, blocking some of the star’s light—in the case of the coal-black planet, blocking surprisingly little of that light.