Identification of Young Stellar Variables with KELT for K2 II: The Upper Scorpius Association

Abstract

High-precision photometry from space-based missions such as K2 and TESS enables detailed studies of young star variability. However, because space-based observing campaigns are often short (e.g., 80 days for K2), complementary long-baseline photometric surveys are critical for obtaining a complete understanding of young star variability, which can change on timescales of minutes to years. We therefore present and analyze light curves of members of the Upper Scorpius association made over 5.5 years by the ground-based Kilodegree Extremely Little Telescope (KELT), which complement the high-precision observations of this region taken by K2 during its Campaigns~2 and 15. We show that KELT data accurately identify the periodic signals found with high-precision K2 photometry, demonstrating the power of ground-based surveys in deriving stellar rotation periods of young stars. We also use KELT data to identify sources exhibiting variability that is likely related to circumstellar material and/or stellar activity cycles; these signatures are often unseen in the short-term K2 data, illustrating the importance of long-term monitoring surveys for studying the full range of young star variability. We provide the KELT light curves as electronic tables in an ongoing effort to establish legacy time-series datasets for young stellar clusters.

arXiv comment11 pages, 6 figures; submitted to MNRAS (comments welcome)

References in corpus (54)

• The Transiting Exoplanet Survey Satellite
• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The K2 Mission: Characterization and Early results
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• A Hipparcos census of the nearby OB associations
• Protoplanetary Disks and Their Evolution
• First Results from the Catalina Real-time Transient Survey
• The WASP Project and the SuperWASP Cameras
• A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission
• A Revised Age for Upper Scorpius and The Star-Formation History Among the F-Type Members of the Scorpius-Centaurus OB Association
• Parallaxes and proper motions for 20 open clusters as based on the new Hipparcos catalogue
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• Keck Spectra of Pleiades Brown Dwarf Candidates and a Precise Determination of the Lithium Depletion Edge in the Pleiades
• The Star-formation History and Accretion-Disk Fraction Among the K-Type Members of the Scorpius-Centaurus OB Association
• CSI 2264: Simultaneous optical and infrared light curves of young disk-bearing stars in NGC 2264 with CoRoT and Spitzer-- evidence for multiple origins of variability
• The Kilodegree Extremely Little Telescope (KELT): A Small Robotic Telescope for Large-Area Synoptic Surveys
• Search for Associations Containing Young stars (SACY): I. Sample & Searching Method
• Evidence for Mass-dependent Circumstellar Disk Evolution in the 5 Myr-old Upper Scorpius OB Association
• KELT-1b: A Strongly Irradiated, Highly Inflated, Short Period, 27 Jupiter-mass Companion Transiting a mid-F Star
• ALMA Observations of Circumstellar Disks in the Upper Scorpius OB Association
• The Disk Population of the Upper Scorpius Association
• The Palomar/Keck Adaptive Optics Survey of Young Solar Analogs: Evidence for a Universal Companion Mass Function
• Improved angular momentum evolution model for solar-like stars II. Exploring the mass dependence
• Mapping the Shores of the Brown Dwarf Desert I.: Upper Scorpius
• Structure of Herbig AeBe disks at the milliarcsecond scale A statistical survey in the H band using PIONIER-VLTI
• The KELT-South Telescope
• The Age and Age Spread of the Praesepe and Hyades Clusters: a Consistent, ~800 Myr Picture from Rotating Stellar Models
• Young "Dipper" Stars in Upper Sco and $\rho$ Oph Observed by K2
• A VLBI Resolution of the Pleiades Distance Controversy
• CSI 2264: Probing the inner disks of AA Tau-like systems in NGC 2264
• Explaining UXOR variability with self-shadowed disks
• Rotation of Late-Type Stars in Praesepe with K2
• New Pre-main-Sequence Stars in the Upper Scorpius Subgroup of Sco-Cen
• Rotation in the Pleiades with K2: II. Multi-Period Stars
• Comparison of the dust and gas radial structure in the transition disk [PZ99] J160421.7-213028
• Dippers and Dusty Disks Edges: A Unified Model
• An ALMA Continuum Survey of Circumstellar Disks in the Upper Scorpius OB Association
• Orbiting Clouds of Material at the Keplerian Co-Rotation Radius of Rapidly Rotating Low Mass WTTs in Upper Sco
• 870 micron Imaging of a Transitional Disk in Upper Scorpius: Holdover from the Era of Giant Planet Formation?
• A continuum of accretion burst behavior in young stars observed by K2
• Time-Series Photometry of Stars in and around the Lagoon Nebula. I. Rotation Periods of 290 Low-Mass Pre-Main-Sequence Stars in NGC 6530
• Dipper disks not inclined towards edge-on orbits
• KELT-10b: The First Transiting Exoplanet from the KELT-South Survey -- A Hot Sub-Jupiter Transiting a V = 10.7 Early G-Star
• Photometry of Variable Stars from Dome A, Antarctica: Results from the 2010 Observing Season
• Long-term variability of T Tauri stars using WASP
• Rotation Periods of Young Brown Dwarfs: K2 Survey in Upper Scorpius
• The Monitor Project: Stellar rotation at 13~Myr: I. A photometric monitoring survey of the young open cluster h~Per
• The peculiar dipping events in the disk-bearing young-stellar object EPIC 204278916
• The Mysterious Dimmings of the T Tauri Star V1334 Tau
• Difference Image Analysis of Defocused Observations with CSTAR
• Kepler observations of A-F pre-main sequence stars in Upper Scorpius: Discovery of six new $\delta$~Scuti and one $\gamma$~Doradus stars
• Angular Momentum Evolution of Young Stars in the Nearby Scorpius-Centaurus OB Association
• Dimming and CO absorption toward the AA Tau protoplanetary disk: An infalling flow caused by disk instability?
• Stellar models simulating the disk-locking mechanism and the evolutionary history of the Orion Nebula cluster and NGC2264

Cited by in corpus (15)

• Rotation of Low-Mass Stars in Upper Scorpius and Rho Ophiuchus with K2
• The many-faceted light curves of young disk-bearing stars in Upper Sco and $\rho$ Oph observed by $K2$ Campaign 2
• Precision Light Curves from TESS Full-Frame Images: A Difference Imaging Approach
• New Young Stars and Brown Dwarfs in the Upper Scorpius Association
• The Many-Faceted Light Curves of Young Disk-bearing Stars in Taurus as Seen by K2
• M Dwarf rotation from the $K2$ young clusters to the field. I. A Mass-Rotation Correlation at 10 Myr
• A ZTF Look at Optical Variability of Young Stellar Objects in the North America and Pelican Nebulae Complex
• The ASAS-SN Catalog of Variable Stars VIII: "Dipper" Stars in the Lupus Star-Forming Region
• Persistent and occasional: searching for the variable population of the ZTF/4MOST sky using ZTF data release 11
• The PDS 110 observing campaign - photometric and spectroscopic observations reveal eclipses are aperiodic
• KELT: The Kilodegree Extremely Little Telescope, a Survey for Exoplanets Transiting Bright, Hot Stars
• Variability of Young Stellar Objects in the Perseus Molecular Cloud
• Scattering and sublimation: a multi-scale view of $\mu$m-sized dust in the inclined disc of HD 145718
• Exploring membership and variability in NGC 7419: An open cluster rich in super giants and Be type stars
• NGTS clusters survey IV. Search for Dipper stars in the Orion Nebular Cluster