A Study of Stellar Spins in 15 Open Clusters

Abstract

We analyze spectroscopic and photometric data to determine the projected inclinations of stars in 11 open clusters, placing constraints on the spin-axis distributions of six clusters. We combine these results with four additional clusters studied by Healy & McCullough (2020) and Healy et al. (2021) to perform an ensemble analysis of their spins. We find that eight out of ten constrained clusters (80%) have spin-axis orientations consistent with isotropy, and we establish a lower limit of four out of ten (40%) isotropic clusters at 75% confidence, assuming no correlation of spins between clusters. We also identify two clusters whose spin-axis distributions can be better described by a model consisting of an aligned fraction of stars combined with an isotropic distribution. However, the inclination values of these stars may be influenced by systematic error, and the small number of stars modeled as aligned in these two clusters precludes the interpretation that their stellar subsets are physically aligned. Overall, no cluster displays an unambiguous signature of spin alignment, and 97% of the stars in our sample are consistent with isotropic orientations in their respective clusters. Our results offer support for the dominance of turbulence over ordered rotation in clumps and do not suggest alignment of rotation axes and magnetic fields in protostars.

arXiv comment35 pages, 15 figures, accepted for publication in ApJ

References in corpus (101)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• emcee: The MCMC Hammer
• The NumPy array: a structure for efficient numerical computation
• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Gaia mission
• The Transiting Exoplanet Survey Satellite
• Embedded Clusters in Molecular Clouds
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• Theory of Star Formation
• The SIMBAD astronomical database
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• A 3D Dust Map Based on Gaia, Pan-STARRS 1 and 2MASS
• The PLATO 2.0 Mission
• The GALAH Survey: Scientific Motivation
• astroquery: An Astronomical Web-Querying Package in Python
• Gaia Data Release 2: Photometric content and validation
• Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
• Global survey of star clusters in the Milky Way II. The catalogue of basic parameters
• On the rotational evolution of solar- and late-type stars, its magnetic origins, and the possibility of stellar gyrochronology
• A Gaia DR2 view of the Open Cluster population in the Milky Way
• Astrophysical parameters of Galactic open clusters
• The Pan-STARRS1 Database and Data Products
• Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way
• The GALAH+ Survey: Third Data Release
• The Thirteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey MApping Nearby Galaxies at Apache Point Observatory
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• The Formation of a Bound Star Cluster: From the Orion Nebula Cluster to the Pleiades
• Unresolved stellar companions with Gaia DR2 astrometry
• Kinematics in Young Star Clusters and Associations with Gaia DR2
• The CatWISE2020 Catalog
• The dynamical distance and intrinsic structure of the globular cluster omega Centauri
• Age determination for 269 $Gaia$ DR2 Open Clusters
• The stellar association around Gamma Velorum and its relationship with Vela OB2
• Rotation periods of 12 000 main-sequence Kepler stars: Dependence on stellar spectral type and comparison with v sin i observations
• SkyMapper Southern Survey: Second Data Release (DR2)
• eleanor: An open-source tool for extracting light curves from the TESS Full-Frame Images
• Disk formation during collapse of magnetized protostellar cores
• Untangling the Galaxy I: Local Structure and Star Formation History of the Milky Way
• A maximum likelihood method for fitting colour-magnitude diagrams
• On the Inference of a Star's Inclination Angle from its Rotation Velocity and Projected Rotation Velocity
• The Gaia-ESO Survey: Kinematic structure in the Gamma Velorum Cluster
• Towards precise stellar ages: combining isochrone fitting with empirical gyrochronology
• The Lithium Depletion Boundary in NGC 2547 as a test of pre-main-sequence evolutionary models
• Older and Colder: The impact of starspots on pre-main sequence stellar evolution
• The SPOTS Models: A Grid of Theoretical Stellar Evolution Tracks and Isochrones For Testing The Effects of Starspots on Structure and Colors
• Extended stellar systems in the solar neighborhood -- V. Discovery of coronae of nearby star clusters
• Spectroscopy of Very Low Mass Stars and Brown Dwarfs in the Lambda Orionis Star Forming Region. I. Enlarging the census down to the planetary mass domain in Collinder 69
• The CFHT Open Star Cluster Survey II -- Deep CCD Photometry of the Old Open Star Cluster NGC 6819
• Spin alignment of stars in old open clusters
• Measurements of Stellar Inclinations for Kepler Planet Candidates II: Candidate Spin-Orbit Misalignments in Single and Multiple-Transiting Systems
• Rotation in NGC 2264: a study based on CoRoT photometric observations
• Turbulence in the Interstellar Medium
• Formation and Evolution of Disks around Young Stellar Objects
• The substellar population of the young cluster lambda Orionis
• Rapid Rotation of Low-Mass Red Giants Using APOKASC: A Measure of Interaction Rates on the Post-main-sequence
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- I. Search for exoplanets and variable stars in the field of 47 Tuc
• The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum cluster and inflated radii in low-mass pre-main-sequence stars
• Characterizing and correcting the proper motion bias of the bright Gaia EDR3 sources
• A New Look at the Old Star Cluster NGC 6791
• The inflated radii of M-dwarfs in the Pleiades
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- II. Search for exoplanets in open clusters of the southern ecliptic hemisphere and their frequency
• The Gaia-ESO Survey: Insights on the inner-disc evolution from open clusters
• Are the spin axes of stars randomly aligned within a cluster?
• The effect of starspots on the radii of low-mass pre-main sequence stars
• Low mass stars, brown dwarf candidates and the mass function of the young open cluster NGC 2547
• Diagnosing the Stellar Population and Tidal Structure of the Blanco1 Star Cluster
• Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation
• Effect of Angular Momentum Alignment and Strong Magnetic Fields on the Formation of Protostellar Disks
• The Gaia-ESO Survey: Empirical determination of the precision of stellar radial velocities and projected rotation velocities
• The Gaia-ESO Survey: the first abundance determination of the pre-main-sequence cluster Gamma Velorum
• The Gaia-ESO Survey: Stellar radii in the young open clusters NGC 2264, NGC 2547 and NGC 2516
• The Mass and Age of Very Low Mass Members of the Open Cluster Alpha Persei
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- III. Exploring the properties of young associations through their variables, dippers, and candidate exoplanets
• A color-period diagram for the open cluster M 48 (NGC 2548), and its rotational age
• Reliability of stellar inclination estimated from asteroseismology: analytical criteria, mock simulations and Kepler data analysis
• Luminosity and Mass Function of the Galactic open cluster NGC 2422
• A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) -- IV. Candidate exoplanets around stars in open clusters: frequency and age-planetary radius distribution
• Improved Main Sequence Turnoff Ages of Young Open Clusters: Multicolor UBV Techniques & the Challenges of Rotation
• Linking the rotation of a cluster to the spins of its stars: The kinematics of NGC6791 and NGC6819 in 3D
• Stellar Spins in the Open Cluster NGC 2516
• A search for radius inflation among active M-dwarfs in Praesepe
• The Binary Fraction and Mass Segregation in Alpha Persei Open Cluster
• Angular Momenta, Magnetization, and Accretion of Protostellar Cores
• WIYN Open Cluster Study LXII: Comparison of Isochrone Systems using Deep Multi-Band Photometry of M35
• Rotating filament in Orion B: Do cores inherit their angular momentum from their parent filament?
• Stellar Spins in the Pleiades, Praesepe, and M35 Open Clusters
• A kinematic perspective on the formation process of the stellar groups in the Rosette Nebula
• WIYN Open Cluster Study LXXIX. M48 (NGC 2548) I. Radial Velocities, Rotational Velocities, and Metallicities of Stars in the Open Cluster M48 (NGC 2548)
• Aggregates of clusters in the Gaia data
• Signature of non-isotropic distribution of stellar rotation inclination angles in the Praesepe cluster
• The alignment is in their stars: on the spin-alignment of stars in star clusters
• Rotation of Kepler field dwarfs and sub giants: Spectroscopic $v\sin I$ from APOGEE
• Are the gyro-ages of field stars underestimated?
• Determination of Starspot Covering Fraction as a function of Stellar Age from Observational Data
• Extreme fragmentation and complex kinematics at the center of the L1287 cloud
• Coadded Spectroscopic Stellar Parameters and Abundances from the LAMOST Low Resolution Survey

Cited by in corpus (6)

• Flaring Activities of Fast Rotating Stars have Solar-like Latitudinal Distribution
• Four ages of rotating stars in the rotation--activity relationship and gyrochronology
• Rotation and activity in late-type members of the young cluster ASCC 123
• A rotation-based census of blue lurker candidates in open clusters
• Spin-up and spin distribution of stellar black holes grown by gas accretion in proto-stellar clusters
• Rotational Velocities and Radii Estimates of Low-Mass Pre-Main Sequence Stars in NGC 2264