NASA 宇宙の記録
今日の天体写真 (APOD)= カレンダーから選ぶ「宇宙の神秘」=

silon Tauri lies 146 light-years away. A K-type red giant star, epsilon Tau is cooler than the Sun, but with about 13 times the solar radius it shines with nearly 100 times the solar luminosity. A member of the Hyades open star cluster the giant star is known by the proper name Ain, and along with brighter giant star Aldebaran, forms the eyes of Taurus the Bull. Surrounded by dusty, dark clouds in Taurus, epsilon Tau is also known to have a planet. Discovered by radial velocity measurements in 2006, epsilon Tauri b is a gas giant planet larger than Jupiter with an orbital period of 1.6 years. And though the exoplanet can't be seen directly, on a dark night its parent star epsilon Tauri is easily visible to the unaided eye.