论文标题
K2-280B-在一个轻度进化的恒星周围的低密度温暖子尾
K2-280b -- a low density warm sub-Saturn around a mildly evolved star
论文作者
论文摘要
我们提出了K2-280B的独立发现和详细表征，这是一个在19.9天中等中度偏心轨道中的过渡性低密度暖尾（E = 0.35 _ { - 0.35 _ { - 0.04}^{+0.05}），来自K2广告系列7。 K2-280B的半径为R_B = 7.50 +/- 0.44 R_EARTH，M_B = 37.1 +/- 5.6 m_earth，平均密度为0.48 _ { - 0.10}^{ +0.13}^{ +0.13} g/cm^3。 The host star is a mildly evolved G7 star with an effective temperature of T_{eff} = 5500 +/- 100 K, a surface gravity of log(g) = 4.21 +/- 0.05 (cgs), and an iron abundance of [Fe/H] = 0.33 +/- 0.08 dex, and with an inferred mass of M_star = 1.03 +/- 0.03 M_sun and a radius of r_star = 1.28 +/- 0.07 r_sun。我们讨论了K2-280B对亚星期行星的测试形成场景的重要性，以及在太阳系中缺少的这一有趣的行星群体的当前样本。
We present an independent discovery and detailed characterisation of K2-280b, a transiting low density warm sub-Saturn in a 19.9-day moderately eccentric orbit (e = 0.35_{-0.04}^{+0.05}) from K2 campaign 7. A joint analysis of high precision HARPS, HARPS-N, and FIES radial velocity measurements and K2 photometric data indicates that K2-280b has a radius of R_b = 7.50 +/- 0.44 R_Earth and a mass of M_b = 37.1 +/- 5.6 M_Earth, yielding a mean density of 0.48_{-0.10}^{+0.13} g/cm^3. The host star is a mildly evolved G7 star with an effective temperature of T_{eff} = 5500 +/- 100 K, a surface gravity of log(g) = 4.21 +/- 0.05 (cgs), and an iron abundance of [Fe/H] = 0.33 +/- 0.08 dex, and with an inferred mass of M_star = 1.03 +/- 0.03 M_sun and a radius of R_star = 1.28 +/- 0.07 R_sun. We discuss the importance of K2-280b for testing formation scenarios of sub-Saturn planets and the current sample of this intriguing group of planets that are absent in the Solar System.
