论文标题
开放星簇的不对称潮汐尾巴：穿越集群的Prah挑战牛顿引力的星星
Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation
论文作者
论文摘要
出生后，所有恒星的大部分都经过了原籍簇的潮汐阈值（PRAH），进入了经典的潮汐尾巴。领先和尾巴测试引力理论中恒星数量之间的不对称性。所有五个带有尾部数据的开放群集（hyades，praesepe，昏迷，硬币 - 高亚州13，NGC 752）在其领先的DCL = 50 pc中明显更多的恒星，而不是尾随的尾巴。使用Jerabkova-Compact-Convergent-Point（CCP）方法，扩展的尾巴已在附近的四个600-2000 Myr Old Open Clusters绘制为DCL> 50 PC。这些是在近圆形的中心轨道上，这是一种估计开放群集的轨道偏心率的公式。在牛顿的引力中，将RAMSES代码的幻影应用于此问题，尾巴几乎是对称的。在Milgromian动力学（MOND）中，不对称到达50 <dCl/PC <200的观察值，在半乳骨周围附近最大，并且可以在apo-galacticon附近稍微倒转，而küpper的表周期过度过度却是不对称间隔的。圆形轨道上的簇由于不对称的溢出而形成轨道偏心，因此与它们的轨道角动量相反。这种积极的动力反馈表明，随着它们的轨道偏心率不断增加，米尔格罗米亚的开放簇可以迅速消亡。未来的工作是更好地描绘出不同年龄段的开放簇围绕潮汐尾巴的必要工作，并开发了Milgromian Direct N-Body代码。
After their birth a significant fraction of all stars pass through the tidal threshold (prah) of their cluster of origin into the classical tidal tails. The asymmetry between the number of stars in the leading and trailing tails tests gravitational theory. All five open clusters with tail data (Hyades, Praesepe, Coma Berenices, COIN-Gaia 13, NGC 752) have visibly more stars within dcl = 50 pc of their centre in their leading than their trailing tail. Using the Jerabkova-compact-convergent-point (CCP) method, the extended tails have been mapped out for four nearby 600-2000 Myr old open clusters to dcl>50 pc. These are on near-circular Galactocentric orbits, a formula for estimating the orbital eccentricity of an open cluster being derived. Applying the Phantom of Ramses code to this problem, in Newtonian gravitation the tails are near-symmetrical. In Milgromian dynamics (MOND) the asymmetry reaches the observed values for 50 < dcl/pc < 200, being maximal near peri-galacticon, and can slightly invert near apo-galacticon, and the Küpper epicyclic overdensities are asymmetrically spaced. Clusters on circular orbits develop orbital eccentricity due to the asymmetrical spill-out, therewith spinning up opposite to their orbital angular momentum. This positive dynamical feedback suggests Milgromian open clusters to demise rapidly as their orbital eccentricity keeps increasing. Future work is necessary to better delineate the tidal tails around open clusters of different ages and to develop a Milgromian direct n-body code.
