J/A+A/693/L4 Bulk metallicity of giant planets around M stars (Mueller+, 2025)
The bulk metallicity of giant planets around M stars.
Mueller S., Helled R.
<Astron. Astrophys. 693, L4 (2025)>
=2025A&A...693L...4M 2025A&A...693L...4M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Stars, M-type ; Exoplanets ;
Binaries, orbits ; Abundances ; Effective temperatures ;
Stars, masses
Keywords: planets and satellites: composition -
planets and satellites: gaseous planets -
planets and satellites: interiors
Abstract:
Determination of the bulk metallicity of giant exoplanets is essential
in order to constrain their formation and evolution pathways and to
compare them to the Solar System. Previous studies inferred an inverse
relation between the mass and bulk metallicity. However, these studies
used data mostly for planets orbiting FGK stars. The recent
discoveries of giant exoplanets around M-dwarf stars present an
opportunity to probe whether they follow a mass-metallicity trend
that is different from that of their FGK counterparts. Using evolution
models, we characterised the interiors of giant exoplanets with
reliable mass-radius measurements that orbit FGK and M-dwarf stars.
We then inferred the mass-metallicity trends for both populations.
We find that the bulk metallicity of giant planets around M stars is
overall lower than that of planets around FGK stars. This yields
mass-metallicity relations for the two populations with similar
slopes but significantly different offsets. The lack of metal-rich
giant planets around M dwarfs could explain the difference in the
inferred offset and could be a result of different formation
conditions. However, there are only 20 successful bulk-metallicity
retrievals for the giant planets around M dwarfs, which results in
rather large uncertainties. Therefore, it is of great importance to
continue detecting these planets with both transit and radial
velocities. Additionally, the characterisation of the atmospheres of
giant planets around M-stars would further help to constrain their
interiors and facilitate investigations of the atmosphere-interior
connection. Such investigations will significantly contribute to our
understanding of the possible formation pathways of giant planets.
Description:
The table contains the data used in the article to infer the
composition of giant exoplanets. It lists the stellar data, planetary
data, inferred planetary bulk metallicity, relative bulk metallicity,
and heavy-element mass.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 203 133 Stellar and planetary data
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Index [1/133] Index (index)
5- 22 A18 --- plName Planetery name (pl_name)
24- 28 F5.2 Mjup plMass Planetery mass (pl_mass)
30- 33 F4.2 Mjup E_plMass Upper uncertainty on plMass (plmasserr1)
35- 39 F5.2 Mjup e_plMass [] Lower uncertainty on plMass (plmasserr2)
41- 44 F4.2 Rjup plRad Planetary radius (pl_rad)
46- 49 F4.2 Rjup E_plRad Upper uncertainty on plRad (plraderr1)
51- 55 F5.2 Rjup e_plRad [] Lower uncertainty on plRad (plraderr2)
57- 64 E8.2 mW/m2 plInstell Instellation flux (pl_instell)
66- 72 F7.2 d plPorb ? Orbital period (plorbitalperiod)
74- 77 F4.2 AU plsmaj ? Semi-major axis (plsemimajor_axis)
79- 84 F6.2 --- plecc ? Eccentricity (pl_eccentricity)
86- 91 F6.2 Gyr stAge ? Mean stellar age (st_age)
93- 98 F6.2 Gyr E_stAge ? Upper uncertainty on stAge (stageupper)
100-105 F6.2 Gyr e_stAge ? Lower uncertainty on stAge (stagelower)
107-110 F4.2 Msun stMass Stellar mass (st_mass)
112-115 F4.2 Msun E_stMass Upper uncertainty on stMass (stmasserr1)
117-121 F5.2 Msun e_stMass [] Lower uncertainty on stMass (stmasserr2)
123-129 F7.2 K stTeff Stellar effective temperature (st_teff)
131-136 F6.2 K E_stTeff ? Upper uncertainty on stTeff (sttefferr1)
138-144 F7.2 K e_stTeff []? Lower uncertainty on stTeff
(sttefferr2)
146-150 F5.2 [Sun] st[Fe/H] ? Stellar metallicity [Fe/H] (st_met)
152-155 F4.2 [Sun] E_st[Fe/H] ? Upper uncertainty on st[Fe/H] (stmeterr1)
157-161 F5.2 [Sun] e_st[Fe/H] []? Lower uncertainty on st[Fe/H]
(stmeterr2)
163-168 F6.2 --- plZbulk ? Planetery bulk metal mass fraction
(pl_zbulk)
170-175 F6.2 --- e_plZbulk ? Uncertainty on plZbulk (plzbulkerr)
177-182 F6.2 --- plZbulkRel ? Relative bulk metal mass fraction
(plzbulkrel) (1)
184-189 F6.2 --- e_plZbulkRel ? Uncertainty on plZbulkRel
(plzbulkrel_err)
191-196 F6.2 Mgeo plMbulk ? Planetary bulk heavy-element mass
(pl_mbulk)
198-203 F6.2 Mgeo e_plMbulk ? Uncertainty on pl_mbulk (plmbulkerr)
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Note (1): This quantity is the ratio of the planetary and stellar bulk metal
mass fraction.
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Acknowledgements:
Simon Mueller, simonandres.mueller(at)uzh.ch
(End) Simon Mueller [University of Zurich], Patricia Vannier [CDS] 16-Dec-2024