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《欧洲南方天文台下一代凌星仪器发现第一颗系外行星》

  • 来源专题：天文仪器与技术信息
  • 编译者： zwg@niaot.ac.cn
  • 发布时间：2017-11-02

  • The Next Generation Transit Survey (NGTS) instrument at ESO’s Paranal Observatory in northern Chile has found its first exoplanet, a hot Jupiter orbiting an M-dwarf star [1] now named NGTS-1. The planet, NGTS-1b, is only the third gas giant to have been observed transiting an M-dwarf star, following Kepler-45b and HATS-6b. NGTS-1b is the largest and most massive of these three, with a radius of 130% and a mass of 80% those of Jupiter.

    The NGTS uses an array of twelve 20-centimetre telescopes to search for the tiny dips in the brightness of a star caused when a planet in orbit around it passes in front of it (“transits”) and blocks some of its light. Once NGTS-1b had been discovered its existence was confirmed by follow-up observations at ESO’s La Silla Observatory: photometric observations with EulerCam on the 1.2-metre Swiss Leonhard Euler Telescope; and spectroscopic investigations with the HARPS instrument on ESO’s 3.6-metre telescope.

    Small planets are relatively common around M-dwarf stars, whereas gas giants like NGTS-1b appear to be rarer around M-dwarfs than they are around stars more like the Sun. This is consistent with current theories of planet formation, but observations of more M-dwarfs are needed before a clear understanding of the numbers of giant planets around them can be arrived at. The NGTS is specifically designed to provide better data on planets around M-dwarf stars, and since they account for around 75% of stars in the Milky Way, studying them will help astronomers to understand the majority population of planets in the Galaxy.

    The future could be very exciting for this exoplanet system as it has the potential to be studied in greater detail by the suite of instruments on board the NASA/ESA/CSA James Webb Space Telescope (JWST) which is due to be launched in 2019.

    Notes

    [1] An M-dwarf is a small, faint star with approximately 8–50% of the mass of the Sun and with a surface temperature of less than 3700°C. 50 of the closest 60 stars to our Solar System are thought to be M-dwarfs, even though not a single one is bright enough to be visible from the Earth with the naked eye.

  • 原文来源：http://www.eso.org/public/announcements/ann17076/
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  • 《欧洲南方天文台8.2米望远镜系外行星成像器SPHERE见证系外行星诞生》
    • 来源专题：天文仪器与技术信息
    • 编译者：zwg@niaot.ac.cn
    • 发布时间：2018-07-06
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  • 《天体物理学家发现了许多有系外行星的多星系》
    • 来源专题：生物安全网络监测与评估
    • 编译者：yanyf@mail.las.ac.cn
    • 发布时间：2019-11-15
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