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SPIRou input catalogue: activity, rotation and magnetic field of cool dwarfs
- Source :
- Monthly Notices of the Royal Astronomical Society, Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2017, 472 (4), pp.4563-4586. ⟨10.1093/mnras/stx2306⟩, Monthly Notices of the Royal Astronomical Society, 2017, 472 (4), pp.4563-4586. ⟨10.1093/mnras/stx2306⟩
- Publication Year :
- 2017
- Publisher :
- HAL CCSD, 2017.
-
Abstract
- Based on optical high-resolution spectra obtained with CFHT/ESPaDOnS, we present new measurements of activity and magnetic field proxies of 442 low-mass K5-M7 dwarfs. The objects were analysed as potential targets to search for planetary-mass companions with the new spectropolarimeter and high-precision velocimeter, SPIRou. We have analysed their high-resolution spectra in an homogeneous way: circular polarisation, chromospheric features, and Zeeman broadening of the FeH infrared line. The complex relationship between these activity indicators is analysed: while no strong connection is found between the large-scale and small-scale magnetic fields, the latter relates with the non-thermal flux originating in the chromosphere. We then examine the relationship between various activity diagnostics and the optical radial-velocity jitter available in the literature, especially for planet host stars. We use this to derive for all stars an activity merit function (higher for quieter stars) with the goal of identifying the most favorable stars where the radial-velocity jitter is low enough for planet searches. We find that the main contributors to the RV jitter are the large-scale magnetic field and the chromospheric non-thermal emission. In addition, three stars (GJ 1289, GJ 793, and GJ 251) have been followed along their rotation using the spectropolarimetric mode, and we derive their magnetic topology. These very slow rotators are good representatives of future SPIRou targets. They are compared to other stars where the magnetic topology is also known. The poloidal component of the magnetic field is predominent in all three stars.<br />to be published in MNRAS
- Subjects :
- [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
FOS: Physical sciences
Astrophysics
01 natural sciences
Spectral line
symbols.namesake
Planet
0103 physical sciences
Astrophysics::Solar and Stellar Astrophysics
010303 astronomy & astrophysics
Chromosphere
Solar and Stellar Astrophysics (astro-ph.SR)
Line (formation)
Physics
Earth and Planetary Astrophysics (astro-ph.EP)
Zeeman effect
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]
010308 nuclear & particles physics
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Astronomy
Astronomy and Astrophysics
individual: GJ 1289
planet search-stars
Magnetic field
Radial velocity
low-mass stars
Stars
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
radial velocity
symbols
Astrophysics::Earth and Planetary Astrophysics
GJ 251
GJ 793
Astrophysics - Earth and Planetary Astrophysics
Subjects
Details
- Language :
- English
- ISSN :
- 00358711 and 13652966
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society, Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2017, 472 (4), pp.4563-4586. ⟨10.1093/mnras/stx2306⟩, Monthly Notices of the Royal Astronomical Society, 2017, 472 (4), pp.4563-4586. ⟨10.1093/mnras/stx2306⟩
- Accession number :
- edsair.doi.dedup.....ecb0dedcf599c5532ff0dfe105bf0ca8