The HARPS search for southern extra-solar planets

Context. We present radial-velocity measurements of eight stars observed with the HARPS Echelle spectrograph mounted on the 3.6-m telescope in La Silla (ESO, Chile). Data span more than ten years and highlight the long-term stability of the instrument. Aims. We search for potential planets orbiting HD 20003, HD 20781, HD 21693, HD 31527, HD 45184, HD 51608, HD 134060 and HD 136352 to increase the number of known planetary systems and thus better constrain exoplanet statistics. Methods. After a preliminary phase looking for signals using generalized Lomb-Scargle periodograms, we perform a careful analysis of all signals to separate bona-fide planets from signals induced by stellar activity and instrumental systematics. We finally secure the detection of all planets using the efficient MCMC available on the Data and Analysis Center for Exoplanets (DACE web-platform), using model comparison whenever necessary. Results. In total, we report the detection of twenty new super-Earth to Neptune-mass planets, with minimum masses ranging from 2 to 30 MEarth and periods ranging from 3 to 1300 days, in multiple systems with two to four planets. Adding CORALIE and HARPS measurements of HD20782 to the already published data, we also improve the characterization of the extremely eccentric Jupiter orbiting this visual companion of HD 20781.

[1]  L. M. M.-T..  Theory of Probability , 1929, Nature.

[2]  日本物理学会,et al.  Progress in Theoretical Physics , 1946, Nature.

[3]  M. L. Lidov.  The evolution of orbits of artificial satellites of planets under the action of gravitational perturbations of external bodies , 1962 .

[4]  Yoshihide Kozai,et al.  Secular perturbations of asteroids with high inclination and eccentricity , 1962 .

[5]  O. C. Wilson.  FLUX MEASUREMENTS AT THE CENTERS OF STELLAR H- AND K-LINES. , 1968 .

[6]  Arthur H. Vaughan,et al.  FLUX MEASUREMENTS OF CA II AND K EMISSION. , 1978 .

[7]  Dainis Dravins,et al.  Photospheric Spectrum Line Asymmetries and Wavelength Shifts , 1982 .

[8]  J. Scargle.  Studies in astronomical time series analysis. II - Statistical aspects of spectral analysis of unevenly spaced data , 1982 .

[9]  S. Baliunas,et al.  Rotation, convection, and magnetic activity in lower main-sequence stars , 1984 .

[10]  William H. Press,et al.  Book-Review - Numerical Recipes in Pascal - the Art of Scientific Computing , 1989 .

[11]  Hartmut Jahreiss,et al.  Preliminary Version of the Third Catalogue of Nearby Stars , 1991 .

[12]  William H. Press,et al.  Numerical recipes in FORTRAN (2nd ed.): the art of scientific computing , 1992 .

[13]  Michel Mayor,et al.  ELODIE: A spectrograph for accurate radial velocity measurements , 1996 .

[14]  Robert A. Donahue,et al.  Activity-Related Radial Velocity Variation in Cool Stars , 1997 .

[15]  European Southern Observatory,et al.  The CORALIE survey for southern extra-solar planets - IX. A 1.3-day period brown dwarf disguised as a planet , 2002 .

[16]  D. Queloz,et al.  The CORALIE survey for southern extra-solar planets VII - Two short-period Saturnian companions to HD 108147 and HD 168746 , 2002, astro-ph/0202457.

[17]  Wm. A. Wheaton,et al.  2MASS All Sky Catalog of point sources. , 2003 .

[18]  F. Bouchy,et al.  The HARPS survey for southern extra-solar planets. II. A 14 Earth-masses exoplanet around μ Arae , 2004, astro-ph/0408471.

[19]  P. Gregory.  Bayesian Logical Data Analysis for the Physical Sciences: Multivariate Gaussian from maximum entropy , 2005 .

[20]  Michel Mayor,et al.  An extrasolar planetary system with three Neptune-mass planets , 2006, Nature.

[21]  R. Garrison,et al.  Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample , 2006, astro-ph/0603770.

[22]  G. Marcy,et al.  High-eccentricity planets from the Anglo-Australian Planet Search , 2006, astro-ph/0603335.

[23]  F. V. Leeuwen.  Validation of the new Hipparcos reduction , 2007, 0708.1752.

[24]  Nuno C. Santos,et al.  Extrasolar Planets: Statistical properties of exoplanets , 2007 .

[25]  Michel Mayor,et al.  Search for exoplanets with the radial-velocity technique : quantitative diagnostics of stellar activity , 2007, 0708.4338.

[26]  X. Delfosse,et al.  Habitable planets around the star Gliese 581 , 2007, 0710.5294.

[27]  L. Hillenbrand,et al.  Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics , 2008, 0807.1686.

[28]  F. Bouchy,et al.  The HARPS search for southern extra-solar planets - XIII. A planetary system with 3 super-Earths (4.2, 6.9, and 9.2 M) , 2008, 0806.4587.

[29]  F. Bouchy,et al.  The HARPS search for southern extra-solar planets - XVII. Super-Earth and Neptune-mass planets in multiple planet systems HD 47 186 and HD 181 433 , 2008, 0812.1608.

[30]  D. Queloz,et al.  Spectroscopic parameters for 451 stars in the HARPS GTO planet search program - Stellar [Fe/H] and the frequency of exo-Neptunes , 2008, 0805.4826.

[31]  M. Zechmeister,et al.  The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms , 2009, 0901.2573.

[32]  B. Skiff,et al.  VizieR Online Data Catalog , 2009 .

[33]  Marc Ollivier,et al.  The CoRoT space mission : early results Special feature The CoRoT-7 planetary system : two orbiting super-Earths , 2009 .

[34]  Michel Mayor,et al.  The HARPS search for southern extra-solar planets - XV. Six long-period giant planets around BD -17 0063, HD 20868, HD 73267, HD 131664, HD 145377, and HD 153950 , 2009 .

[35]  J. Laskar,et al.  The HARPS search for southern extra-solar planets - XXVIII. Up to seven planets orbiting HD 10180: probing the architecture of low-mass planetary systems , 2010, 1011.4994.

[36]  M. López-Morales,et al.  HOW ECCENTRIC ORBITAL SOLUTIONS CAN HIDE PLANETARY SYSTEMS IN 2:1 RESONANT ORBITS , 2008, 0809.1275.

[37]  Michael Wegner,et al.  Ground-based and Airborne Instrumentation for Astronomy III , 2010 .

[38]  A.-M. Lagrange,et al.  Using the Sun to estimate Earth-like planets detection capabilities II. Impact of plages , 2010, 1001.1638.

[39]  Xavier Bonfils,et al.  Disentangling between stellar activity and planetary signals , 2010 .

[40]  Antonio Manescau,et al.  High‐precision calibration of spectrographs , 2010 .

[41]  Daniel C. Fabrycky,et al.  RADIAL VELOCITY PLANETS DE-ALIASED: A NEW, SHORT PERIOD FOR SUPER-EARTH 55 Cnc e , 2010, 1005.4050.

[42]  R. G. West,et al.  WASP-30b: A 61 MJup BROWN DWARF TRANSITING A V = 12, F8 STAR , 2010, 1010.3006.

[43]  R. P. Butler,et al.  A SUPER-EARTH AND TWO NEPTUNES ORBITING THE NEARBY SUN-LIKE STAR 61 VIRGINIS , 2009, 0912.2599.

[44]  S. Udry,et al.  Planetary detection limits taking into account stellar noise - II. Effect of stellar spot groups on radial-velocities , 2011, 1101.0954.

[45]  D. Queloz,et al.  The HARPS search for Earth-like planets in the habitable zone - I. Very low-mass planets around HD 20794, HD 85512, and HD 192310 , 2011, 1108.3447.

[46]  Austin,et al.  KEPLER'S FIRST ROCKY PLANET: KEPLER-10b , 2011, 1102.0605.

[47]  Christophe Lovis,et al.  Planetary detection limits taking into account stellar noise - I. Observational strategies to reduce stellar oscillation and granulation effects , 2010, 1010.2616.

[48]  E. Ford,et al.  A FIRST COMPARISON OF KEPLER PLANET CANDIDATES IN SINGLE AND MULTIPLE SYSTEMS , 2011, 1103.3896.

[49]  M. P. Hobson,et al.  MultiNest: Efficient and Robust Bayesian Inference , 2011 .

[50]  X. Delfosse,et al.  Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program I. Comparison of activity indices , 2011, 1109.0321.

[51]  C. Moutou,et al.  The HARPS search for southern extra-solar planets XXVII. Seven new planetary systems , 2010, 1012.3830.

[52]  M. R. Haas,et al.  A closely packed system of low-mass, low-density planets transiting Kepler-11 , 2011, Nature.

[53]  F. Fressin,et al.  CHARACTERISTICS OF PLANETARY CANDIDATES OBSERVED BY KEPLER. II. ANALYSIS OF THE FIRST FOUR MONTHS OF DATA , 2011, 1102.0541.

[54]  F. Bouchy,et al.  The HARPS search for southern extra-solar planets. XXX. Planetary systems around stars with solar-like magnetic cycles and short-term activity variation , 2011, 1107.1748.

[55]  J. Laskar,et al.  PUMPING THE ECCENTRICITY OF EXOPLANETS BY TIDAL EFFECT , 2011, 1111.5486.

[56]  N. Mowlavi,et al.  Stellar mass and age determinations - I. Grids of stellar models from Z = 0.006 to 0.04 and M = 0.5 to 3.5 M⊙ , 2012, 1201.3628.

[57]  F. Bouchy,et al.  An Earth-mass planet orbiting α Centauri B , 2012, Nature.

[58]  J. Pepper,et al.  RADIAL VELOCITY VARIATIONS OF PHOTOMETRICALLY QUIET, CHROMOSPHERICALLY INACTIVE KEPLER STARS: A LINK BETWEEN RV JITTER AND PHOTOMETRIC FLICKER , 2013, 1310.7152.

[59]  A.-M. Lagrange,et al.  Using the Sun to estimate Earth-like planets detection capabilities IV. Correcting for the convective component , 2013 .

[60]  J. Pepper,et al.  An observational correlation between stellar brightness variations and surface gravity , 2013, Nature.

[61]  C. Moutou,et al.  The HARPS search for southern extra-solar planets - XXXII. New multi-planet systems in the HARPS volume limited sample: a super-Earth and a Neptune in the habitable zone , 2013, 1301.2741.

[62]  A. Wolfgang,et al.  HOW ROCKY ARE THEY? THE COMPOSITION DISTRIBUTION OF KEPLER’S SUB-NEPTUNE PLANET CANDIDATES WITHIN 0.15 AU , 2014, 1409.2982.

[63]  Nuno C. Santos,et al.  SOAP 2.0: A TOOL TO ESTIMATE THE PHOTOMETRIC AND RADIAL VELOCITY VARIATIONS INDUCED BY STELLAR SPOTS AND PLAGES , 2014, 1409.3594.

[64]  L. Rogers.  MOST 1.6 EARTH-RADIUS PLANETS ARE NOT ROCKY , 2014, 1407.4457.

[65]  M. Tsantaki,et al.  Li abundances in F stars: planets, rotation, and Galactic evolution , 2014, 1412.4618.

[66]  France,et al.  PASTIS: Bayesian extrasolar planet validation. I. General framework, models, and performance , 2014, 1403.6725.

[67]  E. Agol,et al.  VALIDATION OF KEPLER'S MULTIPLE PLANET CANDIDATES. II. REFINED STATISTICAL FRAMEWORK AND DESCRIPTIONS OF SYSTEMS OF SPECIAL INTEREST , 2014, 1402.6352.

[68]  John C. Geary,et al.  ARCHITECTURE OF KEPLER'S MULTI-TRANSITING SYSTEMS. II. NEW INVESTIGATIONS WITH TWICE AS MANY CANDIDATES , 2012, The Astrophysical Journal.

[69]  G. Marcy,et al.  THE MASS–RADIUS RELATION FOR 65 EXOPLANETS SMALLER THAN 4 EARTH RADII , 2013, 1312.0936.

[70]  A. Collier Cameron,et al.  Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system , 2013, Proceedings of the International Astronomical Union.

[71]  Andrew Szentgyorgyi,et al.  THE KEPLER-10 PLANETARY SYSTEM REVISITED BY HARPS-N: A HOT ROCKY WORLD AND A SOLID NEPTUNE-MASS PLANET , 2014, 1405.7881.

[72]  Christophe Lovis,et al.  CHARACTERIZATION OF A SPURIOUS ONE-YEAR SIGNAL IN HARPS DATA , 2015, 1508.00596.

[73]  The HARPS search for southern extra-solar planets - XXXVII. Five new long-period giant planets and a system update , 2014, 1412.6591.

[74]  Khadeejah A. Zamudio,et al.  PLANETARY CANDIDATES OBSERVED BY KEPLER. VI. PLANET SAMPLE FROM Q1–Q16 (47 MONTHS) , 2015, 1502.02038.

[75]  Khadeejah A. Zamudio,et al.  PLANETARY CANDIDATES OBSERVED BY KEPLER. VII. THE FIRST FULLY UNIFORM CATALOG BASED ON THE ENTIRE 48-MONTH DATA SET (Q1–Q17 DR24) , 2015, 1512.06149.

[76]  N. Buchschacher,et al.  Analytical determination of orbital elements using Fourier analysis. I. The radial velocity case , 2015, 1512.03298.

[77]  Santiago,et al.  The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles , 2015, 1510.06446.

[78]  A. Collier Cameron,et al.  The HARPS-N Rocky Planet Search. I. HD 219134 b: A transiting rocky planet in a multi-planet system at 6.5 pc from the Sun , 2015 .

[79]  A. Collier Cameron,et al.  The Sun as a planet-host star: proxies from SDO images for HARPS radial-velocity variations , 2016, 1601.05651.

[80]  S. Aigrain,et al.  Radial-velocity fitting challenge - II. First results of the analysis of the data set , 2016, 1609.03674.

[81]  A. Lagrange,et al.  Variability of stellar granulation and convective blueshift with spectral type and magnetic activity. I. K and G main sequence stars , 2016, 1610.02168.

[82]  R. P. Butler,et al.  The LCES HIRES/Keck Precision Radial Velocity Exoplanet Survey , 2017, 1702.03571.

[83]  The Spitzer search for the transits of HARPS low-mass planets - II. Null results for 19 planets , 2017, 1701.01303.