J/other/Sci/382.1031 LHS 3154 RV and activity indicators (Stefansson+, 2023)
A Neptune-mass exoplanet in close orbit around a very low-mass star challenges
formation models.
Stefansson G., Mahadevan S., Miguel Y., Robertson P., Delamer M.,
Kanodia S., Canas C.I., Winn J.N., Ninan J.P., Terrien R.C., Holcomb R.,
Ford E.B., Zawadzki B., Bowler B.P., Bender C.F., Cochran W.D., Diddams S.,
Endl M., Fredrick C., Halverson S., Hearty F., Hill G.J., Lin A.S.J.,
Metcalf A.J., Monson A., Ramsey L., Roy A., Schwab C., Wright J.T.,
Zeimann G.
<Science, 382, 1031-1035 (2023)>
=2023Sci...382.1031S 2023Sci...382.1031S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Infrared
Abstract:
Theories of planet formation predict that low-mass stars should rarely
host exoplanets with masses exceeding that of Neptune. We used radial
velocity observations to detect a Neptune-mass exoplanet orbiting LHS
3154, a star that is nine times less massive than the Sun. The
exoplanet's orbital period is 3.7 days, and its minimum mass is 13.2
Earth masses. We used simulations to show that the high planet-to-star
mass ratio (>3.5x10^-46) is not an expected outcome of either the
core accretion or gravitational instability theories of planet
formation. In the core-accretion simulations, we show that close-in
Neptune-mass planets are only formed if the dust mass of the
protoplanetary disk is an order of magnitude greater than typically
observed around very low-mass stars.
Description:
We observed the low-mass M dwarf LHS 3154, located 15.7531±0.0084pc
from the Sun. We used the Habitable-zone Planet Finder (HPF), a
near-infrared spectrograph (resolving power R=55000) on the 10-m
Hobby-Eberly Telescope (HET) at McDonald Observatory in Texas, USA.
The observations were taken as part of a survey designed to search for
planets around very low-mass dwarfs. We obtained 137 spectra between
23 January 2020 and 13 April 2022, from which we measured the radial
velocity (RV).
Objects:
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RA (2000) DE Designation(s)
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16 06 33.79 +40 54 22.0 LHS 3154 = TIC 24108819
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables1.dat 27 67 Radial Velocities from the Habitable-zone
Planet Finder for LHS 3154
tables2.dat 75 67 Activity indicators from the Habitable-zone
Planet Finder for LHS 3154
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Byte-by-byte Description of file: tables1.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD Barycentric Julian date
16- 21 F6.2 m/s RV Radial velocity
23- 27 F5.2 m/s e_RV Radial velocity error
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Byte-by-byte Description of file: tables2.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD Barycentric Julian date
16- 21 F6.1 m2/s2 dLW Differential Line Width Index
23- 26 F4.1 m2/s2 e_dLW Differential Line Width Index error
28- 33 F6.1 m/s CRX Chromatic Activity Index
35- 39 F5.1 m/s e_CRX Chromatic Activity Index error
41- 45 F5.3 --- IRT1 ? CaII Infrared Triplet Index 1
47- 51 F5.3 --- e_IRT1 ? CaII Infrared Triplet Index 1 error
53- 57 F5.3 --- IRT2 CaII Infrared Triplet Index 2
59- 63 F5.3 --- e_IRT2 CaII Infrared Triplet Index 2 error
65- 69 F5.3 --- IRT3 CaII Infrared Triplet Index 3
71- 75 F5.3 --- e_IRT3 CaII Infrared Triplet Index 3 error
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 18-Jul-2024