arXiv subjects

Yurij N. Krugly

Publications and source records attributed to Yurij N. Krugly.

3 recordsLinked to original sources

arXiv2021

Asteroid pairs: method validation and new candidates

An asteroid pair can be described as two asteroids with highly similar heliocentric orbits that are genetically related but not gravitationally bound. They can be produced by asteroid collisions or rotational fission. Although over 200 asteroid pairs are known, many more are remaining to be identified, especially among the newly discovered asteroids. The purpose of our work is to find new asteroid pairs in the inner part of the main belt with a new pipeline for asteroid pair search, as well as to validate the pipeline on a sample of known asteroid pairs. Initially, we select pair candidates in the five-dimensional space of osculating orbital elements. Then the candidates are confirmed using numerical modeling with the backtrack integration of their orbits including the perturbations from the largest main-belt asteroids, as well as the influence of the non-gravitational Yarkovsky effect. We performed a survey of the inner part of the main belt and found 10 new probable asteroid pairs. Their estimated formation ages lie between 30 and 400 kyr. In addition, our pipeline was tested on a sample of 17 known pairs, and our age estimates agreed with the ones indicated in literature in most of the cases.

astro-ph.EP↗

arXiv2014

A 3-dimensional model of tangential YORP

Tangential YORP, or TYORP, has recently been demonstrated to be an important factor in the evolution of an asteroid's rotation state. It is complementary to normal YORP, or NYORP, which used to be considered previously. While NYORP is produced by non-symmetry in the large-scale geometry of an asteroid, TYORP is due to heat conductivity in stones on the surface of the asteroid. Yet to date TYORP has been studied only in a simplified 1-dimensional model, substituting stones by high long walls. This article for the first time considers TYORP in a realistic 3-dimensional model, also including shadowing and self-illumination effects via ray tracing. TYORP is simulated for spherical stones lying on regolith. The model includes only 5 free parameters, and the dependence of the TYORP on each of them is studied. The TYORP torque appears to be smaller than previous estimates from 1-dimensional model, but still comparable to the NYORP torques. These results can be used to estimate TYORP of different asteroids, and also as a basis for more sophisticated models of TYORP.

astro-ph.EP↗

arXiv2011

Spin vector and shape of (6070) Rheinland and their implications

Main belt asteroids (6070) Rheinland and (54827) 2001NQ8 belong to a small population of couples of bodies which reside on very similar heliocentric orbits. Vokrouhlicky & Nesvorny (2008, AJ 136, 280) promoted a term "asteroid pairs", pointing out their common origin within the past tens to hundreds of ky. Previous attempts to reconstruct the initial configuration of Rheinland and 2001NQ8 at the time of their separation have led to the prediction that Rheinland's rotation should be retrograde. Here we report extensive photometric observations of this asteroid and use the lightcurve inversion technique to directly determine its rotation state and shape. We confirm the retrograde sense of rotation of Rheinland, with obliquity value constrained to be >= 140 deg. The ecliptic longitude of the pole position is not well constrained as yet. The asymmetric behavior of Rheinland's lightcurve reflects a sharp, near-planar edge in our convex shape representation of this asteroid. Our calibrated observations in the red filter also allow us to determine $H_R = 13.68\pm 0.05$ and $G = 0.31\pm 0.05$ values of the H-G system. With the characteristic color index $V-R = 0.49\pm 0.05$ for the S-type asteroids, we thus obtain $H = 14.17\pm 0.07$ for the absolute magnitude of (6070) Rheinland. This a significantly larger value than previously obtained from analysis of the astrometric survey observations. We next use the obliquity constraint for Rheinland to eliminate some degree of uncertainty in the past propagation of its orbit. This is because the sign of the past secular change of its semimajor axis due to the Yarkovsky effect is now constrained. Determination of the rotation state of the secondary component, asteroid (54827) 2001NQ8, is the key element in further constraining the age of the pair and its formation process.

astro-ph.EP↗