论文标题
在太阳的一个parsec中接近的星星:盖亚数据版3号中确定的新的,更准确的相遇
Stars that approach within one parsec of the Sun: New and more accurate encounters identified in Gaia Data Release 3
论文作者
论文摘要
恒星与太阳的紧密相遇可能会通过乌尔云中彗星的重力扰动或暴露于电离辐射。通过通过银河电位集成轨道,我确定了Gaia DR3中有3300万颗恒星中的哪些具有完整的相空间信息接近太阳。 61颗恒星在1 PC内正式接近,尽管仅42个(三分之二)具有高度信心,但其余的是虚假测量值或(IN)二进制系统。大多数星星将在过去或将来遇到6 Myr。由于Gaia径向速度(RVS)的幅度极限,早期/后期的相遇不太常见。首次确定了几个紧密相遇的恒星,并且更精确地确定了先前已知的紧密相遇的相遇时间,距离和速度,这是因为Gaia DR3的明显改善的精度超过了早期版本。 K7矮人GL 710仍然是最接近的遭遇,估计(中位)相遇距离为0.0636 PC(90%置信区间0.0595-0.0678 PC),以1.3 MYR发生。新的第二次最接近的遭遇发生在2.8 Myr以前:这是G3矮人HD 7977,现在是76 PC,在太阳的不到0.05 PC之内,概率为三分之一。白色矮人UPM J0812-352的明显近距离接触可能由于Gaia DR3的不正确RV而伪造。
Close encounters of stars to the Sun could affect life on Earth through gravitational perturbations of comets in the Oort cloud or exposure to ionizing radiation. By integrating orbits through the Galactic potential, I identify which of 33 million stars in Gaia DR3 with complete phase space information come close to the Sun. 61 stars formally approach within 1 pc, although there is high confidence in only 42 (two thirds) of these, the rest being spurious measurements or (in) binary systems. Most of the stars will encounter within the past or future 6 Myr; earlier/later encounters are less common due to the magnitude limit of the Gaia radial velocities (RVs). Several close encountering stars are identified for the first time, and the encounter times, distances, and velocities of previously known close encounters are determined more precisely on account of the significantly improved precision of Gaia DR3 over earlier releases. The K7 dwarf Gl 710 remains the closest known encounter, with an estimated (median) encounter distance of 0.0636 pc (90% confidence interval 0.0595-0.0678 pc) to take place in 1.3 Myr. The new second closest encounter took place 2.8 Myr ago: this was the G3 dwarf HD 7977, now 76 pc away, which approached within less than 0.05 pc of the Sun with a probability of one third. The apparent close encounter of the white dwarf UPM J0812-352 is probably spurious due to an incorrect RV in Gaia DR3.