Searching for possible siblings of the sun from a common cluster based on stellar space velocities

Abstract

We propose a kinematic approach to searching for the stars that could be formed with the Sun in a common "parent" open cluster. The approach consists in preselecting suitable candidates by the closeness of their space velocities to the solar velocity and analyzing the parameters of their encounters with the solar orbit in the past in a time interval comparable to the lifetime of stars. We consider stars from the Hipparcos catalog with available radial velocities. The Galactic orbits of stars have been constructed in the Allen-Santillan potential by taking into account the perturbations from the spiral density wave. We show that two stars, HIP 87382 and HIP 47399, are of considerable interest in our problem. Their orbits oscillate near the solar orbit with an amplitude of ≈250 pc; there are short-term close encounters to distances < 10 pc. Both stars have an evolutionary status and metallicity similar to the solar ones.

Search for kinematic siblings of the sun based on data from the XHIP catalog

“…Compared to our previous paper (Bobylev et al 2011), we relaxed significantly the selection criteria and, therefore, the number of stars for our analysis increased by an order of magnitude.…”

“…The radial velocity measurements are available for 46 392 stars. Previously (Bobylev et al 2011), we worked with the catalogue by Gontcharov (2006) catalogue, which contains the radial velocities for 35 493 Hipparcos stars. There are more stars with measured radial velocities in the XHIP catalogue; new measurements were included for a number of single stars and, what is very important, the data for spectroscopic binaries were checked against the updatable SB9 bibliographic database (Pourbaix et al 2004).…”

“…Bobylev et al (2011) searched for candidates using the Galactic potential model by Allen and Santillan (1991) rigidly tied to R 0 = 8.5 kpc. According to the review, for example, by Foster and Cooper (2010), the present-day value of this distance is R 0 = 8.0 ± 0.4 kpc.…”

“…This problem has been solved in recent years based on stellar proper motions (Brown et al 2010) and total stellar space velocities (Bobylev et al 2011). …”

Iota Horologii Is Unlikely to Be an Evaporated Hyades Star

“…Thus, strictly speaking, ι Hor does not presently move in the same direction as the Hyades cluster. In order to further examine whether these kinematic properties support the idea of a common origin with the Hyades, we computed the stars' orbits in a Galactic potential using galpy and followed the logic from Bobylev et al (2011) and Ramírez et al (2014b) for finding stellar siblings.…”