Stellar Spins in the Open Cluster NGC 2516

Abstract

Measuring the distribution of stellar spin axis orientations in a coeval group of stars probes the physical processes underlying the stars' formation. In this paper, we use spectro-photometric observations of the open cluster NGC 2516 to determine the degree of spin alignment among its stars. We combine TESS light curves, ground-based spectroscopy from the Gaia-ESO and GALAH surveys, broad-band stellar magnitudes from several surveys, and Gaia astrometry to measure 33 stellar inclinations and quantify overall cluster rotation. Our measurements suggest that stellar spins in this cluster are isotropically oriented, while allowing for the possibility that they are moderately aligned. An isotropic distribution of NGC 2516 spins would imply a star-forming environment in which turbulence dominated ordered motion, while a moderately aligned distribution would suggest a more substantial contribution from rotation. We also perform a three-dimensional analysis of the cluster's internal kinematics, finding no significant signatures of overall rotation. Stemming from this analysis, we identify evidence of cluster contraction, suggesting possible ongoing mass segregation in NGC 2516.

arXiv comment22 pages, 15 figures, accepted for publication in ApJ

References in corpus (63)

• 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
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Gaia mission
• The Transiting Exoplanet Survey Satellite
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• Theory of Star Formation
• The SIMBAD astronomical database
• Evolution of binary stars and the effect of tides on binary populations
• Gaia Data Release 2: The astrometric solution
• MESA Isochrones and Stellar Tracks (MIST) 0: Methods for the construction of stellar isochrones
• The GALAH Survey: Scientific Motivation
• astroquery: An Astronomical Web-Querying Package in Python
• Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
• The TESS Input Catalog and Candidate Target List
• 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
• Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way
• The Optical to Mid-Infrared Extinction Law Based on the APOGEE, Gaia DR2, Pan-STARRS1, SDSS, APASS, 2MASS and WISE Surveys
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• Accurate, Empirical Radii and Masses of Planets and their Host Stars with Gaia Parallaxes
• Tidal dissipation in stars and giant planets
• The GALAH Survey: Second Data Release
• Protostellar disk formation and transport of angular momentum during magnetized core collapse
• The dynamical distance and intrinsic structure of the globular cluster omega Centauri
• On the use of Gaia magnitudes and new tables of bolometric corrections
• Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit
• Age determination for 269 $Gaia$ DR2 Open Clusters
• Rotation periods of 12 000 main-sequence Kepler stars: Dependence on stellar spectral type and comparison with v sin i observations
• eleanor: An open-source tool for extracting light curves from the TESS Full-Frame Images
• Fast Star, Slow Star; Old Star, Young Star: Subgiant Rotation as a Population and Stellar Physics Diagnostic
• On the Inference of a Star's Inclination Angle from its Rotation Velocity and Projected Rotation Velocity
• The influence of turbulence during magnetized core collapse and its consequences on low-mass star formation
• Stellar Radial Velocities in the Old Open Cluster M67 (NGC 2682) I. Memberships, Binaries, and Kinematics
• Photometry and membership for low mass stars in the young open cluster NGC 2516
• Measurements of Stellar Inclinations for Kepler Planet Candidates
• Probing the circumstellar structures of T Tauri stars and their relationship to those of Herbig stars
• Spin alignment of stars in old open clusters
• The fraction of binary systems in the core of five Galactic open clusters
• Cluster Difference Imaging Photometric Survey. I. Light Curves of Stars in Open Clusters from TESS Sectors 6 & 7
• Period spacings in red giants IV: Toward a complete description of the mixed-mode pattern
• 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
• On the alignment of classical T Tauri stars with the magnetic field in the Taurus-Auriga molecular cloud
• 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
• A Standard Law for the Equatorward Drift of the Sunspot Zones
• Are the spin axes of stars randomly aligned within a cluster?
• Systematic errors in Gaia DR2 astrometry and their impact on measurements of internal kinematics of star clusters
• The Gaia-ESO Survey: Empirical determination of the precision of stellar radial velocities and projected rotation velocities
• Protoplanetary Disks in the Orion Nebula Cluster: Gas Disk Morphologies and Kinematics as seen with ALMA
• The Gaia-ESO Survey: Stellar radii in the young open clusters NGC 2264, NGC 2547 and NGC 2516
• Reliability of stellar inclination estimated from asteroseismology: analytical criteria, mock simulations and Kepler data analysis
• Linking the rotation of a cluster to the spins of its stars: The kinematics of NGC6791 and NGC6819 in 3D
• Angular Momenta, Magnetization, and Accretion of Protostellar Cores
• A search for radius inflation among active M-dwarfs in Praesepe
• The effect of unresolved binaries on globular cluster proper-motion dispersion profiles
• Signature of non-isotropic distribution of stellar rotation inclination angles in the Praesepe cluster
• Alignment of the Angular Momentum Vectors of Planetary Nebulae in the Galactic Bulge
• The alignment is in their stars: on the spin-alignment of stars in star clusters
• From proper motions to star cluster dynamics: measuring velocity dispersion in deconvolved distribution functions

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• The Gaia-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy
• Stellar Rotation in the Gaia Era: Revised Open Clusters Sequences
• Rotation and Lithium Confirmation of a 500 Parsec Halo for the Open Cluster NGC 2516
• Evidence that the Hot Jupiter WASP-77 A b Formed Beyond Its Parent Protoplanetary Disk's H2O Ice Line
• Rotation periods for cool stars in the open cluster NGC 3532. The transition from fast to slow rotation
• The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets
• Inside the core of a young massive star cluster: 3D MHD simulations
• 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
• Stellar Rotation and Structure of the $\alpha$ Persei Complex: When Does Gyrochronology Start to Work?
• Asteroseismology of the young open cluster NGC 2516 I: Photometric and spectroscopic observations
• Stellar Spins in the Pleiades, Praesepe, and M35 Open Clusters
• The spin, expansion and contraction of open star clusters
• Age-dating the young open cluster UBC 1 with g-mode asteroseismology, gyrochronology, and isochrone fitting
• Comparing Be Star Inclination Angles Determined from H$\alpha$ Fitting and Gravitational Darkening
• A Study of Stellar Spins in 15 Open Clusters
• Rotational Variation Allows for Narrow Age Spread in the Extended Main Sequence Turnoff of Massive Cluster NGC 1846
• Measuring Long Stellar Rotation Periods (>10 days) from TESS FFI Light Curves is Possible: An Investigation Using TESS and ZTF
• Flaring Activities of Fast Rotating Stars have Solar-like Latitudinal Distribution
• Catalog of Integrated-Light Star Cluster Light Curves in TESS
• Apache Point Observatory follow-up of ACcelerating Candidate ExopLanet host Stars (APO ACCELS): Ages for 166 Accelerating Stars in the Northern Hemisphere