Steven Veach

Keeping cool Yawning may be more than an oral stretch for the sleepy. New research by a Princeton postdoc suggests that yawning helps to regulate brain temperature in humans. The study, by evolutionary biologist Andrew Gallup and colleague Omar Eldakar of the University of Arizona, observed subjects outdoors during winter and early summer. In winter, 45 percent of pedestrians yawned in response to seeing pictures of people yawning. In summer, that figure dropped to 24 percent. Gallup hypothesizes that ambient temperature accounts for the difference. When the air is warmer, yawning becomes less useful to the brain. The paper, published in Frontiers in Evolutionary Neuroscience Sept. 22, builds on earlier research that confirmed the brain-cooling effects of yawning in rats.

Dark giant The planet known as TrES-2b has a few notable characteristics: It lies 750 million light-years away from Earth; the same side of the planet always faces its sun; and it is the darkest exoplanet that astrono­mers have found, reflecting just 1 percent of the light that reaches it. Princeton postdoctoral researcher David Spiegel and David Kipping of the Harvard-Smithsonian Center for Astrophysics found the Jupiter-sized TrES-2b using data from NASA’s Kepler spacecraft and reported the discovery in Monthly Notices of the Royal Astronomical Society in August. The planet is not completely dark, according to Spiegel: “It’s so hot that it emits a faint red glow, much like a burning ember or the coils on an electric stove.”