A Radial Limit on Polar Circumbinary Orbits from General Relativity
A Radial Limit on Polar Circumbinary Orbits from General Relativity
复制标题
广义相对论对极圈双星轨道的径向极限
DOI：
10.3847/2041-8213/ac61e1
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Anna C. Childs
中科院分区：
文献类型：
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作者：
S. Lepp;R. Martin;Anna C. Childs
一个围绕偏心轨道双星运行的粒子，要么围绕双星的角动量矢量（循环轨道），要么围绕一个静止的倾角（振动轨道）进行节点进动。在没有广义相对论（GR）的情况下，定态倾角相对于双星角动量矢量（与双星偏心率矢量对齐）倾斜90°，并且不依赖于粒子半长轴。GR引起双星轨道的拱点进动。在接近双星时，粒子的行为不会受到显著影响，并且振动的粒子与双星一起进动。然而，我们发现，静止倾角和所需的最小倾角的天平动都增加与粒子半长轴。有一个临界半径，超过这个半径就没有振动轨道，只有循环轨道，因此对于一个静止的极地轨道物体来说，有一个最大的轨道半径。临界半径是在行星形成区域内的双星与半长轴Au。这对寻找未对准的环双星行星和极环双星盘的径向范围有影响。
A particle orbiting a misaligned eccentric orbit binary undergoes nodal precession either around the binary angular momentum vector (a circulating orbit) or around a stationary inclination (a librating orbit). In the absence of general relativity (GR), the stationary inclination is inclined by 90° to the binary angular momentum vector (aligned with the binary eccentricity vector) and does not depend on the particle semimajor axis. GR causes apsidal precession of the binary orbit. Close to the binary, the behavior of the particle is not significantly affected, and a librating particle precesses with the binary. However, we find that the stationary inclination and the minimum inclination required for libration both increase with the particle semimajor axis. There is a critical radius beyond which there are no librating orbits, only circulating orbits, and therefore there is a maximum orbital radius for a stationary polar-orbiting body. The critical radius is within planet-forming regions around binaries with a semimajor axis ≲1 au. This has implications for the search for misaligned circumbinary planets and the radial extent of polar circumbinary disks.