J/MNRAS/485/3999 Magnetic dipole moments on rocky exoplanets (McIntyre+, 2019)
Planetary magnetism as a parameter in exoplanet habitability.
McIntyre S.R.N., Lineweaver C.H., Ireland M.J.
<Mon. Not. R. Astron. Soc., 485, 3999-4012 (2019)>
=2019MNRAS.485.3999M 2019MNRAS.485.3999M (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets ; Magnetic fields ; Models
Keywords: planets and satellites: general -
planets and satellites: magnetic fields -
planets and satellites: terrestrial planets
Abstract:
Evidence from the Solar system suggests that, unlike Venus and Mars,
the presence of a strong magnetic dipole moment on Earth has helped
maintain liquid water on its surface. Therefore, planetary magnetism
could have a significant effect on the long-term maintenance of
atmosphere and liquid water on rocky exoplanets. We use Olson &
Christensen's (2006E&PSL.250..561O 2006E&PSL.250..561O) model to estimate magnetic dipole
moments of rocky exoplanets with radii Rp=<1.23R⊕. Even when
modelling maximum magnetic dipole moments, only Kepler-186 f has a
magnetic dipole moment larger than the Earth's, while approximately
half of rocky exoplanets detected in the circumstellar habitable zone
have a negligible magnetic dipole moment. This suggests that planetary
magnetism is an important factor when prioritizing observations of
potentially habitable planets.
Description:
Before applying our magnetic moment model, we compile a data base of
rocky exoplanets using the NASA composite exoplanet data base (Akeson
et al. 2013PASP..125..989A 2013PASP..125..989A), in conjunction with the higher precision
radii of Kepler planets given in Fulton & Petigura
(2018AJ....156..264F 2018AJ....156..264F, Cat. J/AJ/156/264) (Table A1). Unknown masses or
radii and their associated uncertainties are estimated using Chen &
Kipping (2017ApJ...834...17C 2017ApJ...834...17C, Cat. J/ApJ/834/17) M-R relationship for
terrestrial planets: Rp∼Mp0.279±0.009.
Following the Chen & Kipping (2017ApJ...834...17C 2017ApJ...834...17C, Cat. J/ApJ/834/17)
definition of the boundary between terrestrial and Jovian planets, we
restrict our sample to exoplanets with radii Rp=<1.23R⊕,
which corresponds to ∼2M⊕. These constraints restrict our
sample to 496 rocky exoplanets (490 tidally locked), nine of which are
located in the circumstellar habitable zone (CHZ) - where the CHZ is
the insolation between recent Venus and ancient Mars as defined by the
Kopparapu et al. (2013ApJ...765..131K 2013ApJ...765..131K) optimistic habitable zone.
Eight of the nine rocky exoplanets from our CHZ subset are tidally
locked.
For each exoplanet we perform 10000 Monte Carlo simulations. These
simulations allow us to determine the median and 68 per cent
confidence intervals on Mmax (maximum magnetic dipole moment)
values.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 74 496 Rocky exoplanets sample (in order of decreasing
dipole moment)
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See also:
J/AJ/156/264 : California-Kepler Survey. VII. Planet radius gap
(Fulton+, 2018)
J/ApJ/834/17 : Mass & radius of planets, moons, low mass stars
(Chen+, 2017)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Planet name
15- 17 A3 --- f_Name Flag on Name (1)
19- 22 F4.2 Mgeo Mass Planet mass
24- 27 F4.2 Mgeo e_Mass Error on Mass
29- 32 F4.2 Rgeo Rad Planet radius
34- 37 F4.2 Rgeo e_Rad Error on Rad
39- 49 F11.7 d Period Orbital period
51- 59 F9.7 d e_Period Error on Period
61- 64 F4.1 Gyr Age Stellar age
66- 69 F4.2 7.4x10+22A*m+2 Mmax Maximum magnetic dipole moment
71- 74 F4.2 7.4x10+22A*m+2 e_Mmax Error on Mmax
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Note (1): Flag as follows:
a = Non-tidally locked planets
b = Planets located in the optimistic CHZ as defined by
Kopparapu et al. (2013ApJ...765..131K 2013ApJ...765..131K, 2014ApJ...787L..29K 2014ApJ...787L..29K,
Cat. J/ApJ/787/L29)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 29-Sep-2022