天文學獎
2015

2015年度邵逸夫天文學奬頒予威廉•伯魯奇(William J Borucki)，以表彰他構思及領導開普勒計劃；這計劃大大增進了對太陽系外行星系及恒星內部的認識。他是美國宇航局艾姆斯研究中心開普勒計劃首席研究員。

1984年，威廉•伯魯奇和奥德麗•薩默斯發表論文，評估以凌星測光法探測太陽系外行星系的可能性。其主要概念是同時監測許多恒星的亮度。行星橫過觀察者(地球)與其寄主星之間的視線時，使所見的寄主星亮度輕微減少，這就是行星存在的證據。亮度減少的現象周期性出現，相隔時間正好就是行星的公轉周期，這周期性特徵有利分辨寄主星亮度起伏的其他原因。凌星現象的深度決定了行星與其寄主星的面積比率。威廉•伯魯奇和奥德麗•薩默斯強調，若要檢測約地球大小的行星，必須於大氣層上方能觀察得到。

Thirty years ago, William Borucki and Audrey Summers published a paper assessing the potential for detecting extrasolar planetary systems by transit photometry. The key concept is to simultaneously monitor the brightness of a large number of stars with a high-precision photometer. Planets are revealed by the dips in brightness they produce when they pass in front of (transit) their host stars. Successive transits by a planet are spaced by its orbit period, which helps to distinguish transits from other sources of stellar variability. Transit depths determine the ratio of the planet’s surface area to that of its host star. Borucki and Summers emphasized that detection of Earth-size planets would require observations from above the atmosphere.

Subsequently, Borucki began a long quest to develop a suitable photometer and to convince the astronomical community and the US National Space and Aeronautics Administration (NASA) that a modest space mission could discover planets potentially capable of harbouring life. Four proposals submitted between 1992 and 1998 were rejected before the fifth was selected in December 2001 as Discovery Mission #10. Mission development began in 2002 and launch occurred in March 2009.