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    There are several techniques for discovering exoplanets (planets orbiting other stars). The first exoplanets were detected by the gravitational effect that they exerted on their host stars. More recent techniques have been able to image the planets. Each method is sensitive to specific types of exoplanets, and when we piece the information together, we can begin to understand the diversity of exoplanets.  Humans have long wondered whether other solar systems with planets like our own Earth might exist among the billions of stars in our galaxy, and this moment will go down as the time when we figured this out.
    ::发现外行星有几种技术(行星环绕其他恒星的轨道) 。 第一批外行星是通过它们对宿主恒星的引力效应探测到的。 更多的最新技术能够映射行星。 每种方法都对特定类型的外行星十分敏感, 当我们将信息拼凑在一起时, 我们就可以开始理解外行星的多样性。 人类早就在想,我们银河系上数十亿颗恒星中是否还存在其他具有像我们地球这样的行星的太阳系, 而这一时刻将随着我们发现这一点而消失。

    The first failures and successes
    ::最初的失败和成功

    The discovery of worlds around other stars has a long with many false starts. In the 1960s, (1901 - 1995) interpreted a small wobble in the position of Barnard's star as an exoplanet. Observations by other astronomers contradicted that result, although van de Kamp never admitted that his claim was in error. In 1991, and Bailes reported in the prestigious Nature journal  the discovery of a planet orbiting the pulsar star PSR 1829-10. They had measured frequency of pulse arrival times and used the Doppler effect to infer the presence of a planet, but later realized that they had not properly accounted for the velocity of the Earth around the Sun. When Lyne retracted the result at a meeting of the American Astronomical Society in January 1992, he received a standing ovation for his scientific integrity and courage.
    ::在1960年代(1901-1995年),将Barnard的恒星位置上的一个微小的波动解释为一个外行星。其他天文学家的观察与这一结果相矛盾,尽管van de Kamp从未承认他的说法有误。1991年和Bailes在著名的《自然》杂志上报道了在脉冲星PSR 1829-10轨道上发现一个行星的情况。它们测量了脉冲到达时间的频率,并利用多普勒效应推断了行星的存在,但后来意识到它们没有适当说明太阳周围地球的速度。当Lyne在1992年1月美国天文学协会会议上收回其结果时,他得到了科学完整性和勇气的表扬。

    There were also a few signals that were initially published with alternative interpretations that later turned out to be exoplanets. In 1988, Campbell, Walker and Yang observed a periodic radial velocity signal in the red giant star, . They tentatively interpreted this as photospheric variability in the star, but additional data by Hatzes and colleagues in 2002 confirmed that this was indeed an orbiting exoplanet.  Another example occurred in 1989 when Latham and colleagues published the discovery of a companion to the star HD 114762; the team cautiously interpreted this as a possible brown dwarf. However, by 2012, this object was reclassified as a massive exoplanet.
    ::在1988年,Campbell、Walker和Yang在红巨星中观测到一个定期的辐射速度信号。它们暂时将这个信号解释为恒星的光球变异,但Hatzes和同事2002年的额外数据证实,这的确是一个轨道外行星网。另一个例子是1989年Latham和同事公布发现一颗恒星的伴侣HD 114762;小组谨慎地将这个信号解释为一个可能的棕色矮星。然而,到2012年,该物体被重新分类为巨大的外行星网。

    The first confirmed exoplanets were very peculiar. and Dale Frail measured periodic variations in the frequency of pulse arrival times to detect two small planets orbiting the pulsar neutron star, in 1992. In 1994, they found one more planet in this system. These discoveries were puzzling because this planetary system should not have survived the supernova explosion of the host star before it evolved to become a spinning neutron star. The planets likely formed in a debris disk around the pulsar. In retrospect, perhaps that discovery should have told us that planet formation was a ubiquitous process. If planets can form around an exploding supernova, then we should have expected that exoplanets were common.
    ::第一个已证实的外行星非常奇特。戴尔·弗莱尔测量了脉冲到达频率的周期变化,以探测两个围绕脉冲星中子星运行的小行星,1992年。1994年,他们在这个系统中发现了另一个行星。这些发现令人费解,因为这个行星系统不应该在宿主星的超新星爆炸演变成为旋转中子星之前幸存下来。行星可能形成于脉冲星周围的碎片盘中。回过头来看,也许发现该发现告诉我们行星形成是一个无处不在的过程。如果行星能够在爆炸的超新星周围形成,那么我们本应该预期外行星是常见的。

    In 1952, astronomer Otto Struve made the remarkable assertion that if a Jupiter-like planet resided very close to its host star, that the gravitational tug of the planet on the star would produce radial velocity variations that might be detected in the stellar spectra with high enough precision measurements.
    ::1952年,天文学家Otto Struve在1952年提出令人瞩目的断言,如果一个类似于木星的行星离主星非常近,恒星上行星的引力拖拉将产生辐射速度变化,在星光光谱中可以检测到这种变化,并进行足够精确的测量。

    Twentieth-century astronomers worked to improve the precision of their techniques, and in 1995, the first exoplanet was finally discovered around a sun-like star. Most astronomers consider the dawn of exoplanets to be November 1995 when and discovered a gas giant planet orbiting the sun-like star 51 Pegasi at the Observatoire de Haute-Provence using the Doppler technique. The interpretation of this radial velocity signal as an exoplanet remained controversial for a few years but is no longer questioned.  51 Peg b was the first confirmed detection of an exoplanet around a main sequence star, and the 2019 Nobel Prize was awarded to Mayor and Queloz.
    ::20世纪天文学家努力提高技术的精确度,1995年,第一个外行星网最终在太阳般的恒星周围被发现。 多数天文学家认为外行星的黎明是1995年11月,当时发现一个气态巨行星在利用多普勒技术在上普罗旺斯天文台绕着太阳星51号Pegasi环绕着一颗气体巨行星运行。 将这一辐射速度信号解释为外行星网,几年来一直引起争议,但不再受到质疑。 51 Peg b是第一个在主要序列恒星周围确证的外行星探测,2019年诺贝尔奖授予市长和奎洛兹。