Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimum

被引:92
作者
Cameron, A. Collier [1 ,3 ,4 ]
Mortier, A. [3 ,4 ,5 ]
Phillips, D. [6 ]
Dumusque, X. [7 ]
Haywood, R. D. [6 ]
Langellier, N. [6 ,8 ]
Watson, C. A. [9 ]
Cegla, H. M. [2 ,7 ]
Costes, J. [9 ]
Charbonneau, D. [6 ]
Coffinet, A. [7 ]
Latham, D. W. [6 ]
Lopez-Morales, M. [6 ]
Malavolta, L. [10 ,11 ]
Maldonado, J. [12 ]
Micela, G. [12 ]
Milbourne, T. [6 ,8 ]
Molinari, E. [13 ]
Saar, S. H. [6 ]
Thompson, S. [5 ]
Buchschacher, N. [7 ]
Cecconi, M. [14 ]
Cosentino, R. [14 ]
Ghedina, A. [14 ]
Glenday, A. [6 ]
Gonzalez, M. [14 ]
Li, C. -H. [6 ]
Lodi, M. [14 ]
Lovis, C. [7 ]
Pepe, F. [7 ]
Poretti, E. [14 ,15 ]
Rice, K. [16 ,17 ]
Sasselov, D. [6 ]
Sozzetti, A. [18 ]
Szentgyorgyi, A. [6 ]
Udry, S. [7 ]
Walsworth, R. [6 ,8 ]
机构
[1] Lowell Observ, 1400 Mars Hill Rd, Flagstaff, AZ 86001 USA
[2] SNSF NCCR PlanetS, Flagstaff, AZ USA
[3] Univ St Andrews, Sch Phys & Astron, SUPA, St Andrews KY16 9SS, Fife, Scotland
[4] Univ St Andrews, Ctr Exoplanet Sci, Coll Gate, St Andrews KY16 9AJ, Fife, Scotland
[5] Cavendish Lab, Astrophys Grp, JJ Thomson Ave, Cambridge CB3 0HE, England
[6] Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
[7] Univ Geneva, Observ Astron, 51 Chemin Maillettes, CH-1290 Sauverny, Switzerland
[8] Harvard Univ, Dept Phys, 17 Oxford St, Cambridge, MA 02138 USA
[9] Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Univ Rd, Belfast BT7 1NN, Antrim, North Ireland
[10] INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy
[11] Univ Padua, Dipartimento Fis & Astron Galileo Galilei, Vicolo Osservatorio 3, I-35122 Padua, Italy
[12] INAF Osservatorio Astron Palermo, Piazza Parlamento 1, I-0134 Palermo, Italy
[13] INAF Osservatorio Astron Cagliari, Via Sci 5, I-09047 Selargius, Italy
[14] INAF Fdn Galileo Galilei, Rambla Jose Ana Fernandez Perez 7, E-38712 Tenerife, Spain
[15] INAF Osservatorio Astron Brera, Via E Bianchi 46, I-23807 Merate, LC, Italy
[16] Univ Edinburgh, Royal Observ, Inst Astron, SUPA, Edinburgh EH9 3HJ, Midlothian, Scotland
[17] Univ Edinburgh, Ctr Exoplanet Sci, James Clerk Maxwell Bldg,Peter Guthrie Tait Rd, Edinburgh EH9 3FD, Midlothian, Scotland
[18] INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy
基金
瑞士国家科学基金会; 英国科学技术设施理事会;
关键词
techniques: radial velocities; Sun: activity; Sun:; faculae; plages; Sun: granulation; sunspots; planets and satellites: detection; HARPS SEARCH; LINE ASYMMETRIES; PLANETS; EXTINCTION; EXTRACTION; CONVECTION;
D O I
10.1093/mnras/stz1215
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The time-variable velocity fields of solar-type stars limit the precision of radial-velocity determinations of their planets' masses, obstructing detection of Earth twins. Since 2015 July, we have been monitoring disc-integrated sunlight in daytime using a purpose-built solar telescope and fibre feed to the HARPS-N stellar radial-velocity spectrometer. We present and analyse the solar radial-velocity measurements and cross-correlation function (CCF) parameters obtained in the first 3 yr of observation, interpreting them in the context of spatially resolved solar observations. We describe a Bayesian mixture-model approach to automated data-quality monitoring. We provide dynamical and daily differential-extinction corrections to place the radial velocities in the heliocentric reference frame, and the CCF shape parameters in the sidereal frame. We achieve a photon-noise-limited radial-velocity precision better than 0.43 m s(-1) per 5-min observation. The day-to-day precision is limited by zero-point calibration uncertainty with an RMS scatter of about 0.4 m s(-1). We find significant signals from granulation and solar activity. Within a day, granulation noise dominates, with an amplitude of about 0.4 m s(-1) and an autocorrelation half-life of 15 min. On longer time-scales, activity dominates. Sunspot groups broaden the CCF as they cross the solar disc. Facular regions temporarily reduce the intrinsic asymmetry of the CCF. The radial-velocity increase that accompanies an active-region passage has a typical amplitude of 5 m s(-1) and is correlated with the line asymmetry, but leads it by 3 d. Spectral line-shape variability thus shows promise as a proxy for recovering the true radial velocity.
引用
收藏
页码:1082 / 1100
页数:19
相关论文
共 56 条
[1]   A simple method to estimate radial velocity variations due to stellar activity using photometry [J].
Aigrain, S. ;
Pont, F. ;
Zucker, S. .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2012, 419 (04) :3147-3158
[2]  
[Anonymous], 1996, BAAS
[3]   ELODIE: A spectrograph for accurate radial velocity measurements [J].
Baranne, A ;
Queloz, D ;
Mayor, M ;
Adrianzyk, G ;
Knispel, G ;
Kohler, D ;
Lacroix, D ;
Meunier, JP ;
Rimbaud, G ;
Vin, A .
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, 1996, 119 (02) :373-390
[4]   Three-dimensional simulations of near-surface convection in main-sequence stars [J].
Beeck, B. ;
Cameron, R. H. ;
Reiners, A. ;
Schuessler, M. .
ASTRONOMY & ASTROPHYSICS, 2013, 558
[5]   The HARPS search for southern extra-solar planets -: X.: A msin i=11 M⊕ planet around the nearby spotted M dwarf GJ 674 [J].
Bonfils, X. ;
Mayor, M. ;
Delfosse, X. ;
Forveille, T. ;
Gillon, M. ;
Perrier, C. ;
Udry, S. ;
Bouchy, F. ;
Lovis, C. ;
Pepe, F. ;
Queloz, D. ;
Santos, N. C. ;
Bertaux, J.-L. .
ASTRONOMY & ASTROPHYSICS, 2007, 474 (01) :293-299
[6]   Fundamental photon noise limit to radial velocity measurements [J].
Bouchy, F ;
Pepe, F ;
Queloz, D .
ASTRONOMY & ASTROPHYSICS, 2001, 374 (02) :733-739
[7]  
Bouguer P., 1729, Essai d'optique sur la gradation de la lumiere
[8]  
BRANDT PN, 1990, ASTRON ASTROPHYS, V231, P221
[9]   PRECISION RADIAL-VELOCITIES WITH AN ABSORPTION CELL [J].
CAMPBELL, B ;
WALKER, GAH .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 1979, 91 (542) :540-545
[10]   STELLAR SURFACE MAGNETO-CONVECTION AS A SOURCE OF ASTROPHYSICAL NOISE. I. MULTI-COMPONENT PARAMETERIZATION OF ABSORPTION LINE PROFILES [J].
Cegla, H. M. ;
Shelyag, S. ;
Watson, C. A. ;
Mathioudakis, M. .
ASTROPHYSICAL JOURNAL, 2013, 763 (02)