Research
-
2025.03.27
Tsinghua Astronomers found the correlation between stellar metallicities and planet mutual inclinations
Our Solar System exhibits a flat architecture, with nearly all planets orbiting within the same plane. Among them, Mercury is the most inclined planet with a mutual inclination of 7 degrees relative to Earth’s orbital plane (Figure 1). Mutual inclination, which refers to the angle between the orbital planes of two planets, serves as a key indicator of the dynamical architecture of planetary sy...
More -
2025.03.19
The Story of Kepler-221 -- A Broken Chain
Kepler-221 is a G-type star hosting four planets. Among these planets, three of them -- b, c, and e – have their orbits following a rhythm known as a three-body resonance. This means that their orbital periods are close to integer, which resembles synchronized dancers following the same beat. For every six orbits of planet b, planet c completes three, and planet e completes one. But there’s a...
More -
2025.02.25
First Direct Measurements of Globular Cluster Mass Loss Through Stellar Streams
Globular clusters are dense, ancient groups of stars orbiting galaxies like the Milky Way, often containing hundreds of thousands to even several million stars. Over billions of years, these clusters gradually lose mass due to two-body relaxation and tidal stripping. This slow unraveling process can eventually cause some clusters to dissolve entirely, contributing their stars to the galaxy's ha...
More -
2024.12.30
Tsinghua astronomers confirm the nature of a rare stellar system
During the collapse of a molecular cloud into stars, some of the remaining material forms a circumstellar disk. In binary systems, this disk may surround the orbits of both stars. The interactions between such a circumbinary disk and the central binary can lead to fascinating astrophysical phenomena. Recently, an international team led by Tsinghua astronomers has identified such a unique object...
More -
2024.12.05
An extremely low-density planet spins slow
Planets are not perfect spheres. For example, Jupiter's equatorial radius is larger than its polar radius by 7%, and this aspherical shape is due to the fast spin of Jupiter, as one day on Jupiter is only 10 hr long. The shape of a planet therefore provides a measure of the rate and the orientation of its spin, which are ultimately related to the formation and evolution history of the planet as...
More