J/AJ/166/167 54 years S-index measurements for λ Ser (Metcalfe+, 2023)
Asteroseismology and Spectropolarimetry of the Exoplanet Host Star.
Metcalfe T.S., Buzasi D., Huber D., Pinsonneault M.H., van Saders J.L.,
Ayres T.R., Basu S., Drake J.J., Egeland R., Kochukhov O., Petit P.,
Saar S.H., See V., Stassun K.G., Li Y., Bedding T.R., Breton S.N.,
Finley A.J., Garcia R.A., Kjeldsen H., Nielsen M.B., Ong J.M.J.,
Rorsted J.L., Stokholm A., Winther M.L., Clark C.A., Godoy-Rivera D.,
Ilyin I.V., Strassmeier K.G., Jeffers S.V., Marsden S.C., Vidotto A.A.,
Baliunas S., Soon W.
<Astron. J., 166, 167 (2023)>
=2023AJ....166..167M 2023AJ....166..167M
ADC_Keywords: Stars, bright; Spectra, optical
Keywords: Spectropolarimetry ; Stellar activity ; Stellar evolution ;
Stellar oscillations ; Stellar rotation
Abstract:
The bright star λSer hosts a hot Neptune with a minimum mass of
13.6M⊕ and a 15.5day orbit. It also appears to be a solar
analog, with a mean rotation period of 25.8days and surface
differential rotation very similar to the Sun. We aim to characterize
the fundamental properties of this system and constrain the
evolutionary pathway that led to its present configuration. We detect
solar-like oscillations in time series photometry from the Transiting
Exoplanet Survey Satellite, and we derive precise asteroseismic
properties from detailed modeling. We obtain new spectropolarimetric
data, and we use them to reconstruct the large-scale magnetic field
morphology. We reanalyze the complete time series of chromospheric
activity measurements from the Mount Wilson Observatory, and we
present new X-ray and ultraviolet observations from the Chandra and
Hubble space telescopes. Finally, we use the updated observational
constraints to assess the rotational history of the star and estimate
the wind braking torque. We conclude that the remaining uncertainty on
the stellar age currently prevents an unambiguous interpretation of
the properties of λSer, and that the rate of angular momentum
loss appears to be higher than for other stars with a similar Rossby
number. Future asteroseismic observations may help to improve the
precision of the stellar age.
Description:
The Transiting Exoplanet Survey Satellite (TESS) observed λSer
during Sector 51 (2022 April 22-2022 May 18) in 20s cadence, which has
been demonstrated to have superior photometric precision to 2 minute
data for bright stars
Objects:
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RA (2000) DE Designation(s)
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15 46 26.61 +07 21 11.0 λ Serpentis = * lam Ser
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig4.dat 18 2388 54-year S-index time series for λ Ser
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See also:
J/ApJ/457/L99 : 25yr CaII-HK obs of F-K nearby stars (Baliunas+, 1996)
J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/MNRAS/444/3517 : BCool survey of solar-type stars (Marsden+ 2014)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)
J/A+A/580/A23 : Stroemgren-Crawford uvbyβ photometry (Paunzen, 2015)
J/ApJS/225/32 : Extended abundance analysis of cool stars (Brewer+, 2016)
J/AJ/152/180 : Bolometric fluxes of eclipsing bin Tycho-2 (Stassun+, 2016)
J/ApJ/835/172 : Kepler asteroseismic LEGACY sample. I. (Lund+, 2017)
J/AJ/153/136 : Planets and host stars with Gaia parallaxes (Stassun+, 2017)
J/ApJ/854/78 : Magnetohydrodynamic (MHD) simulations. II. (Finley+, 2018)
J/A+A/615/A172 : alpha Cen A and B chemical composition (Morel, 2018)
J/A+A/616/A7 : Gaia DR2 radial velocity standard stars (Soubiran+, 2018)
J/MNRAS/495/2363 : Asteroseismology of 36 Kepler subgiants. I. (Li+, 2020)
J/ApJ/900/154 : Mount Wilson S-Index of 94AqrA and 94AqrB (Metcalfe+, 2020)
J/other/NatAs/5.707 : Dwarf stars asteroseismic rotation rates (Hall+, 2021)
J/ApJ/921/122 : Chromospheric acti of ρ CrB and 88 Leo (Metcalfe+, 2021)
J/AJ/163/183 : S-value for 59 Sun-like starswith HIRES & HKP (Baum+, 2022)
J/A+A/660/A141 : Light curve of the active star LQ Hya (Lehtinen+, 2022)
Byte-by-byte Description of file: fig4.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d JD [-807/12440] Julian Date ; JD-2440000
13- 18 F6.4 --- SIndex [0.13/0.67] S-Index value
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 08-Apr-2024