J/ApJ/907/89 Starspots's temperature and area in 337 KIC stars (Herbst+, 2021)
From Starspots to Stellar Coronal Mass Ejections-Revisiting Empirical Stellar
Relations.
Herbst K., Papaioannou A., Airapetian V.S., Atri D.
<Astrophys. J., 907, 89 (2021)>
=2021ApJ...907...89H 2021ApJ...907...89H
ADC_Keywords: Stars, K-type; Stars, M-type; Optical; Magnetic fields;
Effective temperatures
Keywords: Starspots ; Solar energetic particles ; Stellar coronal mass
ejections
Abstract:
Upcoming missions, including the James Webb Space Telescope, will soon
characterize the atmospheres of terrestrial-type exoplanets in
habitable zones around cool K- and M-type stars by searching for
atmospheric biosignatures. Recent observations suggest that the
ionizing radiation and particle environment from active cool planet
hosts may be detrimental to exoplanetary habitability. Since no direct
information on the radiation field is available, empirical relations
between signatures of stellar activity, including the sizes and
magnetic fields of starspots, are often used. Here, we revisit the
empirical relation between the starspot size and the effective stellar
temperature and evaluate its impact on estimates of stellar flare
energies, coronal mass ejections, and fluxes of the associated stellar
energetic particle events.
Description:
The motivation of this study was to investigate the empirical relation
between stellar effective temperatures and the temperatures of
starspots and the relations for eruptive events based on it. To this
end we utilized the stellar sample by Berdyugina+, 2005LRSP....2....8B 2005LRSP....2....8B,
and proposed a new empirical relation, for the first time providing a
corresponding error band.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 66 337 *Derived starspot temperatures, starspot areas
normalized to the area of stars
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Note on table2.dat: Selected stellar Kepler observations of M-, K-, and G-type
stars published in McQuillan+, 2014, J/ApJS/211/24.
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
J/other/Nat/485.478 : Superflares on solar-type stars (Maehara+, 2012)
J/ApJS/209/5 : Superflares of Kepler stars. I. (Shibayama+, 2013)
J/ApJ/797/50 : Global energetics of solar flares. I. (Aschwanden+, 2014)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)
J/A+A/593/A123 : STELLA-SES Radial Velocities of HD 208472 (Ozdarcan+, 2016)
J/ApJ/866/99 : Radii of KIC stars & planets using Gaia DR2 (Berger+, 2018)
J/ApJ/881/9 : EvryFlare. I. Cool stars's flares southern sky (Howard+, 2019)
J/ApJ/871/187 : Spot parameters on KIC solar-type stars (Namekata+, 2019)
J/A+A/625/A27 : II Pegasi spectra with PEPSI (Strassmeier+, 2019)
J/ApJ/895/140 : EvryFlare. II. Parameters 122 cool flare stars (Howard+, 2020)
J/ApJ/902/115 : EvryFlare. III. Superflares Evryscope & TESS (Howard+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 13 I4 K Teff [3300/6400] Effective stellar temperature (1)
15- 24 F10.8 --- DeltaF/F [0.0005/0.11] Stellar brightness variation (2)
26- 29 I4 K Tspot1 [2896/4148] Starspot temperature (3)
31- 34 I4 K Tspot2 [2733/4815] Starspot temperature (this work) (4)
36- 38 I3 K e_Tspot2 [542/753] Uncertainty in Tspot2
40- 45 F6.4 --- Ratio1 [0.0006/0.15] Starspot areas normailzed to area of
star (3)
47- 52 F6.4 --- Ratio2 [0.0007/0.17] Starspot areas normailzed to area of
star from this work (4)
54- 59 F6.4 --- E_Ratio2 [0.0005/0.5] Upper uncertainty in Ratio2
61- 66 F6.4 --- e_Ratio2 [0.0001/0.1] Lower uncertainty in Ratio2
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Note (1): From McQuillan+, 2014, J/ApJS/211/24.
Note (2): Normalized by the average stellar brightness.
Note (3): Based on the relations according to Berdyugina+, 2005LRSP....2....8B 2005LRSP....2....8B
(Equations 1 and 2).
Note (4): Based on the newly-derived relations given in Equations 5 and 6.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 02-Jun-2022