OGLE-2005-BLG-071Lb, THE MOST MASSIVE M DWARF PLANETARY COMPANION?-猫眼课题宝

DOI：

10.1088/0004-637x/695/2/970

发表时间：

2008-04

期刊：

The Astrophysical Journal

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

S. Dong;A. Gould;A. Udalski;Jay Anderson;G. Christie;B. Gaudi;M. Jaroszynski;M. Kubiak;M. Szymański;G. Pietrzyński;G. Pietrzyński;I. Soszyński;O. Szewczyk;O. Szewczyk;K. Ulaczyk;Ł. Wyrzykowski;Ł. Wyrzykowski;D. Depoy;D. Fox;A. Gal-yam;C. Han;S. Lépine;J. Mccormick;E. Ofek;B.-G. Park;R. Pogge;F. Abe;D. Bennett;I. Bond;T. Britton;A. Gilmore;J. Hearnshaw;Y. Itow;K. Kamiya;P. Kilmartin;A. Korpela;K. Masuda;Y. Matsubara;M. Motomura;Y. Muraki;S. Nakamura;K. Ohnishi;C. Okada;N. Rattenbury;T. Saito;T. Sako;M. Sasaki;D. Sullivan;T. Sumi;P. Tristram;T. Yanagisawa;P. Yock;T. Yoshoika;R. Collaborations;M. Albrow;J. Beaulieu;S. Brillant;H. Calitz;A. Cassan;K. Cook;C. Coutures;S. Dieters;D. Prester;J. Donatowicz;P. Fouqué;J. Greenhill;K. Hill;M. Hoffman;K. Horne;U. Jørgensen;S. Kane;D. Kubas;J. Marquette;R. Martin;P. Meintjes;J. Menzies;K. Pollard;K. Sahu;C. Vinter;J. Wambsganss;A. Williams;M. Bode;D. Bramich;M. Burgdorf;C. Snodgrass;I. A. Steele;V. Doublier;C. Foellmi

我们结合了所有可用的信息来确定OGLE-2005-BLG-071Lb的性质，这是通过微透镜发现的第二颗行星，也是在高倍放大事件中发现的第一颗行星。这些包括来自哈勃太空望远镜的光度测量和天体测量，以及从地面光曲线中提取的高阶效应的约束，如微透镜视差、行星轨道运动和有限源效应。我们的初步分析得出结论，木星行星OGLE-2005-BLG-071Lb的宿主是一颗位于前景盘中的M矮星，质量M = 0.46±0.04 M☉，距离Dl = 3.2±0.4 kpc，厚盘运动学vLSR ~ 103 km s−1。从最佳拟合模型来看，这颗行星的质量为Mp = 3.8±0.4 m木星，与它的宿主之间的投影距离为r⊥= 3.6±0.2AU，因此它的平衡温度为T ~ 55k，与海王星相似。简并模型给出了类似的行星质量Mp = 3.4±0.4 m木星，但其投影距离较小，r⊥= 2.1±0.1AU，平衡温度更高，T ~ 71 K。这些初步分析的结果表明，OGLE-2005-BLG-071Lb可能是迄今为止发现的由M矮星承载的质量最大的行星。然而，在核心吸积的情况下，在M矮行星系统的外部区域形成如此高质量的行星同伴被预测是不可能的。这一初步分析假设（基于真实但有限的证据），与光源重合的未透镜光实际上是由于透镜，即行星宿主。然而，这些警告大多可以通过事件发生几年后的一次天文测量来解决。

We combine all available information to constrain the nature of OGLE-2005-BLG-071Lb, the second planet discovered by microlensing and the first in a high-magnification event. These include photometric and astrometric measurements from the Hubble Space Telescope, as well as constraints from higher order effects extracted from the ground-based light curve, such as microlens parallax, planetary orbital motion, and finite-source effects. Our primary analysis leads to the conclusion that the host of Jovian planet OGLE-2005-BLG-071Lb is an M dwarf in the foreground disk with mass M = 0.46 ± 0.04 M☉, distance Dl = 3.2 ± 0.4 kpc, and thick-disk kinematics vLSR ∼ 103 km s−1. From the best-fit model, the planet has mass Mp = 3.8 ± 0.4 MJupiter, lies at a projected separation r⊥ = 3.6 ± 0.2AU from its host, and so has an equilibrium temperature of T ∼ 55 K, that is, similar to Neptune. A degenerate model gives similar planetary mass Mp = 3.4 ± 0.4 MJupiter with a smaller projected separation, r⊥ = 2.1 ± 0.1AU, and higher equilibrium temperature, T ∼ 71 K. These results from the primary analysis suggest that OGLE-2005-BLG-071Lb is likely to be the most massive planet yet discovered that is hosted by an M dwarf. However, the formation of such high-mass planetary companions in the outer regions of M dwarf planetary systems is predicted to be unlikely within the core-accretion scenario. There are a number of caveats to this primary analysis, which assumes (based on real but limited evidence) that the unlensed light coincident with the source is actually due to the lens, that is, the planetary host. However, these caveats could mostly be resolved by a single astrometric measurement a few years after the event.

OGLE-2005-BLG-071Lb, THE MOST MASSIVE M DWARF PLANETARY COMPANION?

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