Estimating the ages of open star clusters from properties of their extended tidal tails

Abstract

The most accurate current methods for determining the ages of open star clusters, stellar associations and stellar streams are based on isochrone fitting or the lithium depletion boundary. We propose another method for dating these objects based on the morphology of their extended tidal tails, which have been recently discovered around several open star clusters. Assuming that the early-appearing tidal tails, the so called tidal tails I, originate from the stars released from the cluster during early gas expulsion, or that they form in the same star forming region as the cluster (i.e. being coeval with the cluster), we derive the analytical formula for the tilt angle $\beta$ between the long axis of the tidal tail and the orbital direction for clusters or streams on circular trajectories. Since at a given Galactocentric radius, $\beta$ is only a function of age $t$ regardless of the initial properties of the cluster, we estimate the cluster age by inverting the analytical formula $\beta =\beta (t)$. We illustrate the method on a sample of $12$ objects, which we compiled from the literature, and we find a reasonable agreement with previous dating methods in $\approx 70$% of the cases. This can probably be improved by taking into account the eccentricity of the orbits and by revisiting the dating methods based on stellar evolution. The proposed morphological method is suitable for relatively young clusters (age $\lesssim 300$ Myr), where it provides a relative age error of the order of $10$ to $20$% for an error in the observed tilt angle of $5^{\circ }$.

arXiv comment13 pages, 5 figures, 1 table, Accepted by ApJ

References in corpus (46)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Embedded Clusters in Molecular Clouds
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Ages for illustrative field stars using gyrochronology: viability, limitations and errors
• Dynamical evolution of star clusters in tidal fields
• The Ages of Stars
• The Formation of a Bound Star Cluster: From the Orion Nebula Cluster to the Pleiades
• Keck Spectra of Pleiades Brown Dwarf Candidates and a Precise Determination of the Lithium Depletion Edge in the Pleiades
• A comprehensive set of simulations studying the influence of gas expulsion on star cluster evolution
• The Second Survey of the Molecular Clouds in the Large Magellanic Cloud by NANTEN. II. Star Formation
• Inverse dynamical population synthesis: Constraining the initial conditions of young stellar clusters by studying their binary populations
• Untangling the Galaxy I: Local Structure and Star Formation History of the Milky Way
• The Exciting Lives of Giant Molecular Clouds
• A Catalog of Young Stellar Groups and Clusters Within 1kpc of the Sun
• The Effect of Gas Loss on the Formation of Bound Stellar Clusters
• The Spitzer Space Telescope Survey of the Orion A and B Molecular Clouds II: the Spatial Distribution and Demographics of Dusty Young Stellar Objects
• Tidal Tails of Star Clusters
• Structure and kinematics of the Taurus star-forming region from Gaia-DR2 and VLBI astrometry
• The Hyades tidal tails revealed by Gaia DR2
• Residual gas expulsion from young globular clusters
• Star Cluster Evolution, Dynamical Age Estimation and the Kinematical Signature of Star Formation
• On the structure of tidal tails
• Bayesian Ages for Early-Type Stars from Isochrones Including Rotation, and a Possible Old Age for the Hyades
• Extended stellar systems in the solar neighborhood -- V. Discovery of coronae of nearby star clusters
• No wide spread of stellar ages in the Orion Nebula Cluster
• Extended stellar systems in the solar neighborhood - II. Discovery of a nearby 120° stellar stream in Gaia DR2
• The lithium depletion boundary and the age of the Hyades cluster
• Panchromatic Hubble Andromeda Treasury XVIII. The High-mass Truncation of the Star Cluster Mass Function
• The lithium-rotation connection in the 125 Myr-old Pleiades cluster
• TESS reveals that the nearby Pisces-Eridanus stellar stream is only 120 Myr old
• Clustered star formation as a natural explanation of the Halpha cutoff in disc galaxies
• 3D Morphology of Open Clusters in the Solar Neighborhood with Gaia EDR3: its Relation to Cluster Dynamics
• The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum cluster and inflated radii in low-mass pre-main-sequence stars
• Did the infant R136 and NGC 3603 clusters undergo residual gas expulsion?
• On the recent star formation history of the Milky Way disk
• Uncovering a 260 pc wide, 35 Myr old filamentary relic of star formation
• Rotation and Lithium Confirmation of a 500 Parsec Halo for the Open Cluster NGC 2516
• A stellar relic filament in the Orion star forming region
• The $\mu$ Tau Association: A 60 Myr-Old Coeval Group at 150 pc from the Sun
• A lithium depletion boundary age of 22 Myr for NGC 1960
• Tidal tails of open star clusters as probes to early gas expulsion I: A semi-analytic model
• Extended stellar systems in the solar neighborhood. IV. Meingast 1: the most massive stellar stream in the solar neighborhood
• Chronostar: a novel Bayesian method for kinematic age determination. I. Derivation and application to the β Pictoris Moving Group
• Tidal tails of open star clusters as probes to early gas expulsion II: Predictions for Gaia
• The Gaia-ESO survey: A lithium depletion boundary age for NGC 2232

Cited by in corpus (8)

• Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation
• Tidal tails of open clusters
• A Gaia astrometric view of the open clusters Pleiades, Praesepe and Blanco 1
• Exploring Galactic open clusters with Gaia I. An examination in the first kiloparsec
• Nearby open clusters with tidal features: golden sample selection and 3D structure
• Finding the dispersing siblings of young open clusters. Dynamical traceback simulations using Gaia DR3
• Tidal Tails of Nearby Open Clusters. II. A Review of Simulated Properties and the Reliability of Observational Catalogues
• Dynamical model of Praesepe and its tidal tails