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

Herbert, Carys, Froebrich, Dirk, Scholz, Aleks (2023) A survey for variable young stars with small telescopes: VII -- Spot Properties on YSOs in IC5070. Monthly Notices of the Royal Astronomical Society, 520 (4). pp. 5433-5445. ISSN 0035-8711. (doi:10.1093/mnras/stac3051) (KAR id:97806)

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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 (Teff), and a coverage of 0.05 - 0.4. Six more have hot spots, with temperatures up to 3000 K above Teff 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 Teff<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.

Item Type: Article
DOI/Identification number: 10.1093/mnras/stac3051
Additional information: For the purpose of open access, the author(s) has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising
Uncontrolled keywords: Astrophysics; Solar and Stellar Astrophysics; stars: formation, stars: pre-main-sequence, stars: rotation, starspots, stars: variables: T Tauri, Herbig Ae/Be
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Funders: Science and Technology Facilities Council (
Depositing User: Dirk Froebrich
Date Deposited: 04 Nov 2022 16:25 UTC
Last Modified: 27 Feb 2024 12:27 UTC
Resource URI: (The current URI for this page, for reference purposes)

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Froebrich, Dirk.

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