2025PASP..137i4201S -
Publ. Astron. Soc. Pac., 137, part no 9, 4201 (2025/September-0)
10,000 Resolved Triples from Gaia: Empirical Constraints on Triple Star Populations.
SHARIAT C., EL-BADRY K. and NAOZ S.
Abstract (from CDS):
We present a catalog of ∼10,000 resolved triple star systems within 500 pc of the Sun, constructed using Gaia data. The triples include main-sequence, red giant, and white dwarf components spanning separations of 10-50,000 au. A well-characterized selection function allows us to constrain intrinsic demographics of the triple star population. We find that (a) all systems are compatible with being hierarchical and dynamically stable; (b) mutual orbital inclinations are isotropic for wide triples but show modest alignment as the systems become more compact; (c) primary masses follow a Kroupa initial mass function weighted by the triple fraction; (d) inner binary orbital periods, eccentricities, and mass ratios mirror those of isolated binaries, including a pronounced twin excess (mass ratios greater than 0.95) out to separations of 1000+ au, suggesting a common formation pathway; (e) tertiary mass ratios follow a power-law distribution with slope -1.4; (f) tertiary orbits are consistent with a log-normal period distribution and thermal eccentricities, subject to dynamical stability. Informed by these observations, we develop a publicly available prescription for generating mock triple star populations. Finally, we estimate the catalog's completeness and infer the intrinsic triple fraction, which rises steadily with primary mass: from 5% at ≲0.5 M⊙ to 35% at 2 M⊙. The public catalog provides a robust testbed for models of triple star formation and evolution.
Abstract Copyright:
© 2025. The Author(s). Published by IOP Publishing Ltd on behalf of the Astronomical Society of the Pacific (ASP).
Journal keyword(s):
Three-body problem - Binary stars - Stellar evolution - Star formation - Trinary stars
Status at CDS
:
Large table(s) will be appraised for possible ingestion in VizieR.
Simbad objects:
38
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