TIDAL LIMITS TO PLANETARY HABITABILITY
TIDAL LIMITS TO PLANETARY HABITABILITY
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DOI：
10.1088/0004-637x/700/1/l30
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发表时间：
2009-07-20
影响因子：
7.9
通讯作者：
Raymond, Sean N.
中科院分区：
文献类型：
--
作者：
Barnes, Rory;Jackson, Brian;Raymond, Sean N.
主序星的宜居带（HZ）传统上被定义为拦截适量恒星通量以允许行星表面有水的轨道范围。在这些区域中发现的绕 M 星运行的类地系外行星，由于恒星光度降低而靠近，也可能经历显着的潮汐加热。对于类地系外行星来说，潮汐加热可能跨越很宽的范围，并可能显着影响地表附近的条件。例如，如果系外行星上的加热速率接近或大于 I0（其中潮汐驱动火山活动，至少每 1 Myr 重新出现一次行星表面）并产生类似的表面条件，那么生命的发展似乎不太可能。另一方面，如果潮汐加热速率低于引发板块构造的最小值，那么二氧化碳可能无法通过俯冲进行回收，从而导致失控的温室效应，从而对地球造成消毒。这两种情况代表了宜居性的潜在边界，并与主序、低质量恒星的传统 HZ 范围一起呈现。我们提出了一个修改后的 HZ，其中包含恒星日射和潮汐加热。我们将这些标准应用到 GJ 581 d 上，发现它位于传统的 HZ 中，但仅凭其潮汐加热可能不足以满足板块构造的要求。
The habitable zones (HZs) of main-sequence stars have traditionally been defined as the range of orbits that intercept the appropriate amount of stellar flux to permit surface water on a planet. Terrestrial exoplanets discovered to orbit M stars in these zones, which are close-in due to decreased stellar luminosity, may also undergo significant tidal heating. Tidal heating may span a wide range for terrestrial exoplanets and may significantly affect conditions near the surface. For example, if heating rates on an exoplanet are near or greater than that on I0 (where tides drive volcanism that resurfaces the planet at least every 1 Myr) and produce similar surface conditions, then the development of life seems unlikely. On the other hand, if the tidal heating rate is less than the minimum to initiate plate tectonics, then CO2 may not be recycled through subduction, leading to a runaway greenhouse that sterilizes the planet. These two cases represent potential boundaries to habitability and are presented along with the range of the traditional HZ for main-sequence, low-mass stars. We propose a revised HZ that incorporates both stellar insolation and tidal heating. We apply these criteria to GJ 581 d and find that it is in the traditional HZ, but its tidal heating alone may be insufficient for plate tectonics.