Exploring rotational properties and the YORP effect in asteroid families

The long-term dynamical evolution of asteroid families is governed by the interplay between orbital and rotational evolution driven by thermal forces and collision. We aim to observationally trace the rotational evolution of main-belt asteroid families over Gyr timescales.

We analyzed rotational properties of 8739 asteroids with spin period measurements and 3794 asteroids with obliquity determinations across 28 asteroid families spanning ages from 14 Myrs to 3 Gyrs. Family ages, membership and members proper elements were retrieved from AstDys (Spoto et al., 2015). The spin vectors are mainly determined from Gaia DR3 photometry (Durech et al., 2023 and Cellino et al., 2024), although for some asteroids the spin vectors were retrieved from LCBD (Warner et al., 2009). The diameter $D$, the albedo $p_V$ (and their correspoding uncertainties) were retrieved from the WISE/NEOWISE survey (Masiero et al., 2011), along with their absolute magnitude $H$. For asteroids not having a diameter measurement, we calculated it using the usual formula $D = \frac{1329}{\sqrt{\hat{p}_V}} \cdot 10^{-0.2 H}\,\,[{\rm km}]$, where $H$ is the absolute magnitude retrieved from the Asteroid Family Portal (Novakovic et al., 2022) and $\hat{p}_V$ is the median albedo for the family.

Here a description of the dataset columns:

name: identifier of the asteroid

a: proper semi-major axis [AU]

e: proper eccentricity

i: sine of the proper inclination

H: absolute magnitude [mag]

D: diameter [km]

D_err: uncertainty associated with the diameter estimation [km]

pv: albedo

pv_err: uncertainty associated with the albedo

fam_num: identifier of asteroids that gives the name to the family

fam_name: name of the family

fam_age: weighted average age of the family. Spoto+15 provides age estimation for both sides of the V-shape. For simplicity, we adopted the weighted average [Myr]

dt_fam_age: uncertainty associated with fam_age [Myr]

a_center: semi-major axis value of the intersection of the two sides of the V-shape [AU]

elon: ecliptic longitude

elat: ecliptic latitude

P: sideral rotation period [h]

obl: cosine of the inclination of the rotation axis

flag: identify from which dataset the spin vectors are taken.