Investigating 16 Open Clusters in the Kepler/K2-Gaia DR3 field. I. Membership, Binary, and Rotation

TL;DR

This study analyzes 16 open clusters using Gaia DR3 and Kepler/K2 data to determine membership, binary systems, and stellar rotation, establishing an empirical rotation-age-color relation for clusters aged 700-4000 Myr.

Contribution

It provides a comprehensive catalog of cluster members, binary candidates, and rotation periods, and develops a new empirical relation linking stellar rotation, age, and color for older clusters.

Findings

Binary fractions vary from 9% to 44% across clusters.

Rotation features of binaries are similar but more scattered than single stars.

An empirical rotation-age-color relation is established for 700-4000 Myr ages.

Abstract

Using data from the Gaia Data Release 3 (Gaia DR3) and Kepler/K2, we present a catalog of 16 open clusters with ages ranging from 4 to 4000 Myr, which provides detailed information on membership, binary systems, and rotation. We assess the memberships in 5D phase space, and estimate the basic parameters of each cluster. Among the 20,160 members, there are 4,381 stars identified as binary candidates and 49 stars as blue straggler stars. The fraction of binaries vary in each cluster, and the range between 9% to 44%. We obtain the rotation periods of 5,467 members, of which 4,304 are determined in this work. To establish a benchmark for the rotation-age-color relation, we construct color-period diagrams. We find that the rotational features of binaries are similar to that of single stars, while features for binaries are more scattered in the rotation period. Moreover, the morphology of the color-period relationship is already established for Upper Scorpius at the age of 19 Myr, and some stars of varying spectral types (i.e. FG-, K-, and M-type) show different spin-down rates after the age of ~110 Myr. By incorporating the effects of stalled spin-down into our analysis, we develop an empirical rotation-age-color relation, which is valid with ages between 700 - 4000 Myr and colors corresponding to a range of 0.5 < (G_BP-G_RP)0 < 2.5 mag.