On June 27, the astronomers at Slooh.com and the Institute of Astrophysics of the Canary Islands (IAC), home of the largest telescope on Earth, presented a live observation of an exoplanet passing across the face of its home star. It was the first live broadcast of such an event, and was sufficiently extraordinary that the King of Spain was in attendance to inaugurate the telescopes before the show.
The exoplanet that made the transit is called TrES 2b. It orbits its home star GSC 03549-02811 in the constellation Draco. TrES 2b is just a little larger than Jupiter, but it’s a totally alien world. While Jupiter is extremely cold, the outer layers of TrES 2b have a temperature of nearly a thousand degrees Celsius, hot enough to vaporize many metals and molecules. It’s also the darkest exoplanet yet discovered, darker than coal or even black acrylic paint, reflecting just 1% of the light that falls on it. No one yet knows why.
During the show on June 27, Slooh and IAC astronomers made a measurement using the Carlos Sanchez infrared telescope of the very slight dip in the brightness as the planet passed across the face of its star. The astronomers also discussed the state-of-the-art technology needed to make this delicate observation, and they spoke with Dr. Lisa Kaltenegger of Cornell University about the diversity of exoplanets discovered so far and what the future holds for this exciting area of astronomical research.
You can see the recording of the broadcast at this link. You might want to skip ahead in the video by a few minutes to see the start of the broadcast. It lasts more than 2 hours, but it’s packed with interesting discussion about exoplanets.