相关论文: No Death Star -- For Now
We analyze findings of the Stardust mission that brought to the Earth dust from the 81P/Wild 2 coma. Just as the data of the Deep Impact mission to 9P/Tempel 1, they are at odds with the widely accepted condensation/sublimation comet…
The Oort cloud is usually thought of as a collection of icy comets inhabiting the outer reaches of the Solar system, but this picture is incomplete. We use simulations of the formation of the Oort cloud to show that ~4% of the small bodies…
Most flares on the Sun occur at random, but there is a small percentage of "sympathetic flaring" -- the triggering of one flare by another. Previously there had been no widespread confirmation of sympathetic flares on other stars. In this…
Traditionally runaway stars are O and B type stars with large peculiar velocities.We want to extend this definition to young stars (up to ~50 Myr) of any spectral type and identify those present in the Hipparcos catalogue applying different…
A list of 4,131 dwarfs, subgiants, and giants located, or suspected to be located, within 33 parsecs of the Sun is presented. All the stars are drawn from the new LSPM-north catalog of 61,976 stars with annual proper motions larger than…
We numerically investigate the possibility that a close stellar encounter could account for the high inclinations of the Kuiper belt, as originally proposed by Ida, Larwood and Burkert, however we consider encounters with pericenters within…
Several observations suggest that the Solar system has been located in a region affected by massive stellar feedback for at least a few Myr; these include detection of live $^{60}\text{Fe}$ in deep-sea archives and Antarctic snow, the broad…
Passing stars (also called stellar flybys) have notable effects on the solar system's long-term dynamical evolution, injection of Oort cloud comets into the solar system, properties of trans-Neptunian objects, and more. Based on a…
Young stars are mostly found in dense stellar environments, and even our own Solar system may have formed in a star cluster. Here, we numerically explore the evolution of planetary systems similar to our own Solar system in star clusters.…
Comet C/2013 A1 (siding Spring) will experience a high velocity encounter with Mars on October 19, 2014 at a distance of 135,000 km +- 5000 km from the planet center. We present a comprehensive analysis of the trajectory of both the comet…
Stars formed in clusters can encounter other stars at close distances. In typical open clusters in the Solar neighbourhood containing hundreds or thousands of member stars, ten to twenty per cent of Solar-mass member stars are expected to…
Observations of both star-forming regions and young, gas-free stellar associations indicate that most nearby molecular clouds form stars only over a short time span before dispersal; large-scale flows in the diffuse interstellar medium have…
Motivated by recent data on comets in the low corona, we discuss destruction of sun impacting comets in the dense lower solar atmosphere. Perihelion distances q less than the solar radius and incident masses Mo much greater than 1E12 g are…
Parker Solar Probe (PSP) aims at exploring the nascent solar wind close to the Sun. Meanwhile, PSP is also expected to encounter small objects like comets and asteroids. In this work, we survey the ephemerides to find a chance of recent…
Correlation analysis of gamma-ray burst coordinates and nearby stars, registered on 2008-2011, revealed 5 coincidences with angular accuracy better than 0.1 degree. The random probability is $7\times 10^{-7}$, so evidencing that coincident…
An instability among the giant planets' orbits can match many aspects of the Solar System's current orbital architecture. We explore the possibility that this dynamical instability was triggered by the close passage of a star or substellar…
The arrival of solid particles from outside our solar system would present us with an invaluable source of scientific information. Attempts to detect such interstellar particles among the meteors observed in Earth's atmosphere have almost…
The Integrated Science Investigation of the Sun (IS$\odot$IS) energetic particle instrument suite on Parker Solar Probe is dedicated to measuring energetic ions and electrons in the near-Sun environment. It includes a half-sky-viewing…
The importance of understanding the current and historical galactic environments of cool stars is discussed. The penetration of interstellar gas into a stellar astrosphere is a function of the interaction of the star with the interstellar…
Probable past and future close encounters of open clusters with known characteristics over 64 million years have been calculated by integrating the orbits of cluster centers in the Galactic potential using the _galpy_ package. It has been…