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Authordc.contributor.authorBarnes, J. R. 
Authordc.contributor.authorJenkins, James Stewart es_CL
Authordc.contributor.authorJones, H.R.A. es_CL
Authordc.contributor.authorJeffers, S. V. es_CL
Authordc.contributor.authorRojo Rubke, Patricio es_CL
Authordc.contributor.authorArriagada, P. es_CL
Authordc.contributor.authorJordán, A. es_CL
Authordc.contributor.authorMinniti, D. es_CL
Authordc.contributor.authorTuomi, M. es_CL
Authordc.contributor.authorPinfield, D. J. es_CL
Authordc.contributor.authorAnglada Escudé, Guillem 
Admission datedc.date.accessioned2014-09-30T19:12:59Z
Available datedc.date.available2014-09-30T19:12:59Z
Publication datedc.date.issued2014-02-20
Cita de ítemdc.identifier.citationMNRAS 439, 3094–3113 (2014)en_US
Identifierdc.identifier.otherdoi:10.1093/mnras/stu172
Identifierdc.identifier.urihttp://repositorio.uchile.cl/handle/2250/126482
General notedc.descriptionArtículo de publicación ISIen_US
Abstractdc.description.abstractWe present radial velocity measurements of a sample of M5V–M9V stars from our Red-Optical Planet Survey, operating at 0.652–1.025 µm. Radial velocities for 15 stars, with rms precision down to 2.5 m s−1 over a week-long time-scale, are achieved using thorium–argon reference spectra. We are sensitive to planets with mp sin i ≥ 1.5 M⊕ (3 M⊕ at 2σ) in the classical habitable zone, and our observations currently rule out planets with mp sin i > 0.5 MJ at 0.03 au for all our targets. A total of 9 of the 15 targets exhibit rms < 16 m s−1, which enables us to rule out the presence of planets with mp sin i > 10 M⊕ in 0.03 au orbits. Since the mean rotation velocity is of the order of 8 km s−1 for an M6V star and 15 km s−1 for M9V, we avoid observing only slow rotators that would introduce a bias towards low axial inclination (i 90◦) systems, which are unfavourable for planet detection. Our targets with the highest v sin i values exhibit radial velocities significantly above the photon-noise-limited precision, even after accounting for v sin i. We have therefore monitored stellar activity via chromospheric emission from the Hα and Ca II infrared triplet lines. A clear trend of log10(LHα/Lbol) with radial velocity rms is seen, implying that significant starspot activity is responsible for the observed radial velocity precision floor. The implication that most late M dwarfs are significantly spotted, and hence exhibit time varying line distortions, indicates that observations to detect orbiting planets need strategies to reliably mitigate against the effects of activity-induced radial velocity variationsen_US
Lenguagedc.language.isoen_USen_US
Publisherdc.publisherRoyal Astronomical Societyen_US
Keywordsdc.subjecttechniques: radial velocitiesen_US
Títulodc.titlePrecision radial velocities of 15 M5–M9 dwarfsen_US
Document typedc.typeArtículo de revistaen_US


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