A survey for variable young stars with small telescopes: VII -- Spot Properties on YSOs in IC5070

Abstract

We present measurements of spot properties on 31 young stellar objects, based on multi-band data from the HOYS (Hunting Outbursting Young Stars) project. On average the analysis for each object is based on 270 data points during 80 days in at least 3 bands. All the young low-mass stars in our sample show periodic photometric variations. We determine spot temperatures and coverage by comparing the measured photometric amplitudes in optical bands with simulated amplitudes based on atmosphere models, including a complete error propagation. 21 objects in our sample feature cool spots, with spot temperatures 500 - 2500 K below the stellar effective temperature ($T_{\mathrm{eff}}$), and a coverage of 0.05 - 0.4. Six more have hot spots, with temperatures up to 3000 K above $T_{\mathrm{eff}}$ and coverage below 0.15. The remaining four stars have ambiguous solutions or are AA Tau-type contaminants. All of the stars with large spots (i.e. high coverage $>0.1$) are relatively cool with $T_{\mathrm{eff}}<4500$ K, which could be a result of having deeper convection zones. Apart from that, spot properties show no significant trends with rotation period, infrared excess, or stellar properties. Most notably, we find hot spots in stars that do not show $K-W2$ infrared excess, indicating the possibility of accretion across an inner disk cavity or the presence of plage.

arXiv commentAccepted for publication by MNRAS. 13 pages, 7 figures, 2 tables

References in corpus (22)

• The chemical composition of the Sun
• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• Magnetic fields of non-degenerate stars
• Near-Infrared Photometric Variability of Stars Toward the Orion A Molecular Cloud
• On the formation of H-alpha line emission around classical T Tauri stars
• Can we predict the global magnetic topology of a pre-main sequence star from its position in the Hertzsprung-Russell diagram?
• Accretion Disks around Young Stars: Lifetimes, Disk Locking and Variability
• The large-scale magnetic field and poleward mass accretion of the classical T Tauri star TW Hya
• Are solar brightness variations faculae- or spot-dominated?
• The Formation of a Stellar Association in the NGC 7000/IC 5070 Complex: Results from Kinematic Analysis of Stars and Gas
• Hot spots and a clumpy disk: Variability of brown dwarfs and stars in the young Sigma Ori cluster
• Discovering Protostars and their Host Clusters via WISE
• The First Extensive Spectroscopic Study of Young Stars in the North America and Pelican Nebulae Region
• A survey for variable young stars with small telescopes: First results from HOYS-CAPS
• Accreting pre-main sequence models and abundance anomalies in globular clusters
• Doppler Images and Chromospheric Variability of TWA 17
• Variability in young very low mass stars: Two surprises from spectrophotometric monitoring
• A survey for variable young stars with small telescopes: II -- Mapping a protoplanetary disk with stable structures at 0.15 AU
• A wide survey for circumstellar disks in the Lupus complex
• A survey for variable young stars with small telescopes: IV -- Rotation Periods of YSOs in IC5070
• Magnetic activity and accretion on FU Tau A: Clues from variability
• A survey for variable young stars with small telescopes: III -- Warm spots on the active star V1598Cyg

Cited by in corpus (1)

• Variability of Young Stellar Objects in the Perseus Molecular Cloud