J/MNRAS/496/5423 4 planet-hosting stars asteroseismic masses (Malla+, 2020)
Asteroseismic masses of four evolved planet-hosting stars using SONG and TESS:
resolving the retired A-star mass controversy.
Malla S.P., Stello D., Huber D., Montet B.T., Bedding T.R., Andersen M.F.,
Grundahl F., Jessen-Hansen J., Hey D.R., Palle P.L., Deng L., Zhang C.,
Chen X., Lloyd J., Antoci V.
<Mon. Not. R. Astron. Soc. 496, 5423-5435 (2020)>
=2020MNRAS.496.5423M 2020MNRAS.496.5423M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Stars, masses
Keywords: techniques: radial velocity - stars: evolution -
stars: fundamental parameters - stars: oscillations
Abstract:
The study of planet occurrence as a function of stellar mass is
important for a better understanding of planet formation. Estimating
stellar mass, especially in the red giant regime, is difficult. In
particular, stellar masses of a sample of evolved planet-hosting stars
based on spectroscopy and grid-based modelling have been put to
question over the past decade with claims they were overestimated.
Although efforts have been made in the past to reconcile this dispute
using asteroseismology, results were inconclusive. In an attempt to
resolve this controversy, we study four more evolved planet-hosting
stars in this paper using asteroseismology, and we revisit previous
results to make an informed study of the whole ensemble in a
self-consistent way. For the four new stars, we measure their masses
by locating their characteristic oscillation frequency, numax, from
their radial velocity time series observed by SONG. For two stars, we
are also able to measure the large frequency separation, Delta nu,
helped by extended SONG single-site and dual-site observations and new
TESS observations. We establish the robustness of the numax-only-based
results by determining the stellar mass from Delta nu, and from both
Delta nu and numax. We then compare the seismic masses of the full
ensemble of 16 stars with the spectroscopic masses from three
different literature sources. We find an offset between the seismic
and spectroscopic mass scales that is mass-dependent, suggesting that
the previously claimed overestimation of spectroscopic masses only
affects stars more massive than about 1.6M☉.
Description:
We tabulate the observing parameters for the four targets in our
sample, observed using the Stellar Observations Network Group (SONG)
telescope nodes at Tenerife and Delingha. We also tabulate the
observed and derived parameters for each of our targets. The updated
results from Stello et al. (2017MNRAS.472.4110S 2017MNRAS.472.4110S) are also provided
here. We also provide the approximate frequencies of individual modes
extracted from the echelle diagrams of gamma Cep and 24 Sex. Lastly,
we provide the stellar masses for the evolved planet-hosting stars
used for the ensemble study in this work across various literature
sources
Objects:
----------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------
10 23 28.37 -00 54 08.1 24 Sex = HIP 50887
18 10 31.64 +54 17 11.6 HD 167042 = HIP 89047
20 16 06.00 +04 34 50.9 HD 192699 = HIP 99894
21 06 39.84 +03 48 11.2 HD 200964 = HIP 104202
23 39 20.90 +77 37 56.5 gamma Cep = HIP 116727
----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 73 7 Observing parameters for targets
(all Tenerife except where noted)
table2.dat 94 4 Observed parameters of the evolved
planet-hosting stars
table3.dat 30 8 Updated Results from
Stello et al. (2017MNRAS.472.4110S 2017MNRAS.472.4110S)
table4.dat 23 8 Approximate frequencies of individual modes
extracted from the echelle diagrams of
gamma Cep and 24 Sex
tableb1.dat 74 19 Stellar masses for the evolved planet-hosting
stars used for the ensemble study in Sec. 6
across various literature sources
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See also:
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
J/A+A/475/1003 : Stellar parameters of G and K giant stars (Hekker+, 2007)
J/A+A/487/373 : Spectroscopic parameters of 451 HARPS-GTO stars (Sousa+, 2008)
J/A+A/526/A71 : C abundances in G and K nearby stars (da Silva+, 2011)
J/A+A/543/A160 : Normalized spectra of 82 Kepler red giants (Thygesen+, 2012)
J/A+A/557/A70 : Evolved planet hosts - stellar parameters (Mortier+, 2013)
J/A+A/555/A150 : Physical parameters of cool solar-type stars (Tsantaki+, 2013)
J/A+A/616/A33 : Stellar parameters of 372 giant stars (Stock+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Name of the star
11- 20 A10 --- n_Star Note on Star
22- 31 A10 "date" Obs.date1 First date of observation
32 A1 --- --- [-]
33- 42 A10 "date" Obs.date2 Last date of observation
44- 47 F4.2 mag Vmag V magnitude
49- 52 I4 s Texp Exposure time
54- 58 I5 --- Nexp Number of exposures
60- 62 A3 --- R Spectrograph Resolution
64- 65 I2 d Nnight Number of observation nights
67- 68 I2 d Nspan Length of the timeseries
70- 73 F4.2 m/s sigmaRV Median radial velocity precision
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Name of the star
11- 14 F4.2 [cm/s2] logg Spectroscopic surface gravity (1)
16- 19 F4.2 [cm/s2] e_logg Error in spectroscopic surface gravity
21- 24 I4 K Teff Spectroscopic effective temperature (1)
26- 27 I2 K e_Teff Error in spectroscopic effective temperature
29- 33 F5.2 [-] [Fe/H] Metallicity (1)
35- 38 F4.2 [-] e_[Fe/H] Error in metallicity
40- 44 F5.2 mas plx Hipparcos Parallax (2)
46- 49 F4.2 mas e_plx Error in Hipparcos Parallax
51- 54 F4.2 Msun Mspec Spectroscopic stellar mass
56- 59 F4.2 Msun e_Mspec Error in spectroscopic stellar mass
61- 65 F5.2 Lsun L Derived Luminosity (3)
67- 70 F4.2 Lsun e_L Error in derived luminosity
72- 74 I3 uHz numax-pre Predicted numax
76- 77 I2 uHz e_numax-pre Error in predicted numax
79- 81 I3 uHz numax-obs Observed numax
83- 84 I2 uHz e_numax-obs Error in observed numax
86- 89 F4.2 Msun Mseis Numax only based asteroseismic mass
91- 94 F4.2 Msun e_Mseis Error in numax only based asteroseismic mass
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Note (1): Spectroscopic parameters (log g, Teff, [Fe/H]) are obtained from
Exoplanet Orbit Database, which refers to Mortier et al.
(2013, Cat. J/A+A/557/A70).
Similar to Stello et al. (2017MNRAS.472.4110S 2017MNRAS.472.4110S), we assume e_Teff=100K and
e_[Fe/H]=0.1dex to derive luminosities, predicted numax and numax-only
based asteroseismic masses instead of the quoted uncertainties in Teff
and [Fe/H] (Thygesen et al. 2012, Cat. J/A+A/543/A160).
Note (2): Source for the parallax: Hipparcos (van Leeuwen, 2007, Cat. I/311)
Note (3): To be conservative, we used the largest of the two asymmetric errors
obtained from isoclassify.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Star Name of the star
11- 15 F5.1 uHz numax Characteristic frequency of oscillation for
the star
17- 20 F4.1 uHz e_numax Error in numax
22- 25 F4.2 Msun Mseis numax-only based asteroseismic masses
27- 30 F4.2 Msun e_Mseis Error in Mseis
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 F5.1 uHz Freq(GC) Approximate frequencies of individual modes
extracted from the echelle diagrams of
gamma Cep (GC)
7- 11 A5 --- Deg(GC) Degree of the mode of oscillation
in column Freq(GC)
13- 17 F5.1 uHz Freq(24S) Approximate frequencies of individual modes
extracted from the echelle diagrams
of 24 Sex (24S)
19- 23 A5 --- Deg(24S) Degree of the mode of oscillation
in column Freq(24S)
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Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Star Name of the star
11- 14 F4.2 Msun MTS13-SO08 ? Spectroscopic mass of the star from
Mortier et al. (2013, J/A+A/557/A70) (1)
16- 19 F4.2 Msun e_MTS13-SO08 ? Error in MTS13-SO08
21- 24 F4.2 Msun MHM07 ? Spectroscopic mass of the star from
Mortier et al. (2013, J/A+A/557/A70) (2)
26- 29 F4.2 Msun e_MHM07 ? Error in MHM07
31- 34 F4.2 Msun MJofre ? Spectroscopic mass of the star from
Jofre et al. (2015, J/A+A/574/A50) (3)
36- 39 F4.2 Msun e_MJofre ? Error in MJofre
41- 45 F5.3 Msun MStock ? Spectroscopic mass of the star from the
Stock et al. (2018, J/A+A/616/A33) (4)
47- 51 F5.3 Msun E_MStock ? Positive error in MStock
53- 57 F5.3 Msun e_MStock ? Negative error in MStock
59- 62 F4.2 Msun Mseis Mass of the star from asteroseismology
64- 67 F4.2 Msun E_Mseis Positive error in Mseis
69- 72 F4.2 Msun e_Mseis Negative error in Mseis
74 A1 --- Ref [efg] Reference for the
asteroseismic mass (5)
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Note (1): derived using the Tsantaki et al. (2013, J/A+A/555/A150, TS13) line
list for stars cooler than 5200K and Sousa et al. (2008, J/A+A/487/373, SO08)
line list for hotter stars
Note (2): derived using the Hekker & Melendez (2007, J/A+A/475/1003, HM07)
line list
Note (3): using the iron line lists by da Silva et al.
(2011, J/A+A/526/A71, DS11)
Note (4): Stock et al. (2018, J/A+A/616/A33) did not use a line list directly.
Instead, they used the Teff, [Fe/H] and logg values by Hekker & Melendez
(2007, J/A+A/475/1003).
Note (5): Reference for the Asteroseismic mass as follows:
e = This work
f = Updated values of seismic masses from Stello et al. (2017MNRAS.472.4110S 2017MNRAS.472.4110S)
g = North et al. (2017MNRAS.472.1866N 2017MNRAS.472.1866N)
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Acknowledgements:
Sai Prathyusha Malla, s.malla(at)student.unsw.edu.au
(End) Patricia Vannier [CDS] 18-Jun-2020