Collaborative Research: A gravitational inventory of the solar system using high precision minor planet astrometry

美国国家科学基金会的传统时空调查(LSST)将使用维拉·C·鲁宾天文台在2023-2033年期间拍摄半个天空的图像。研究人员将提高小行星天空位置测量的精确度，允许它们被用作探索太阳系引力的“测试粒子”。这些天体的高精度位置将被用来研究可能存在于太阳系外的“X行星”的潜在引力效应。这项工作将大大提高LSST测量恒星和行星运动的精度，从而间接使其他天文学家受益。该项目将让宾夕法尼亚大学和哈佛-史密森天体物理中心参与天体物理研究的年轻科学家来自代表性不足的群体，并将支持两个机构的一名研究生。它将通过一个旨在吸引第一代/低收入本科生参与研究的计划，扩大宾夕法尼亚大学本科生夏季研究的参与。通过结合数以千计的特洛伊木马的数百万次LSST观测，这些物体在10年内的有效运动可以测量到10米的精度。结合木星和土星航天器的测距数据，通过观察特洛伊木马在LSST有生之年完成绕太阳一周的轨道，将有可能更准确和具体地了解外太阳系的引力。20万颗最亮的主带小行星(MBA)将获得1米以下的精度。这种集体测量精度使人们能够探测到潜伏在太阳系外的一颗未被发现的“X行星”的引力。测试粒子之间的近距离通道将允许确定可能有10个特洛伊木马和150-250个MBA的质量。通过综合所有相互遇到的信号，应该可以测量直径约15公里的MBA和直径约50公里的特洛伊木马的质量和亮度之间的平均关系。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The NSF's Legacy Survey of Space and Time (LSST) will use the Vera C. Rubin Observatory to image over half the sky during 2023-2033. The investigators will improve the accuracy of sky position measurements for minor planets, allowing them to be used as "test particles" for exploring the gravitational forces in the solar system. The highly precise positions of these bodies will be used to study the potential gravitational effects of “planet X,” which might exist in the outer solar system. This work will indirectly benefit other astronomers by substantially improving the accuracy of LSST measurements of the motions of stars and planets. The program will involve young scientists from under-represented groups in astrophysical research at both the University of Pennsylvania and the Harvard-Smithsonian Center for Astrophysics and will support one graduate student at each institution. It will expand participation in summer research for undergraduates at Penn through a program directed at bringing first-generation / low-income undergraduates into research. By combining millions of LSST observations of thousands of Trojans, the effective motion of these objects over 10 years can be measured to 10-meter accuracy. Combined with ranging data from spacecraft at Jupiter and Saturn, a more accurate and specific understanding of gravity in the outer solar system will be possible by watching the Trojans complete an orbit around the Sun over LSST's lifetime. Accuracy below 1 meter will be obtained from the 200,000 brightest main belt asteroids (MBAs). This collective measurement accuracy allows detection of the gravity of a "Planet X" lurking undiscovered in the outer solar system. Close passages between the test particles will allow determination of the masses of perhaps 10 Trojans and 150-250 MBAs. By combining the signals all the mutual encounters, it should be possible to measure the mean relation between mass and brightness for MBAs down to about 15 km diameter and Trojans down to about 50 km diameter.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.