WASP-54b, WASP-56b and WASP-57b: Three new sub-Jupiter mass planets from SuperWASP ⋆

We present three newly discovered sub-Jupiter mass planets from the SuperWASP survey: WASP-54b is a heavily bloated planet of mass 0.636(-0.024)(+0.025) M-J and radius 1.653(-0.083)(+0.090) R-J. It orbits a F9 star, evolving off the main sequence, every 3.69 days. Our MCMC fit of the system yields a slightly eccentric orbit (e = 0.067(-0.025)(+ 0.033)) for WASP-54b. We investigated further the veracity of our detection of the eccentric orbit for WASP-54b, and we find that it could be real. However, given the brightness of WASP-54 V = 10.42 mag, we encourage observations of a secondary eclipse to draw robust conclusions on both the orbital eccentricity and the thermal structure of the planet. WASP-56b and WASP-57b have masses of 0.571(-0.035)(+ 0.034) M-J and 0.672(-0.046)(+ 0.049) M-J, respectively; and radii of 1.092(-0.033)(+ 0.035) R-J for WASP-56b and 0.916(-0.014)(+0.017) R-J for WASP-57b. They orbit main sequence stars of spectral type G6 every 4.67 and 2.84 days, respectively. WASP-56b and WASP-57b show no radius anomaly and a high density possibly implying a large core of heavy elements; possibly as high as similar to 50 M-circle plus in the case of WASP-57b. However, the composition of the deep interior of exoplanets remains still undetermined. Thus, more exoplanet discoveries such as the ones presented in this paper, are needed to understand and constrain giant planets' physical properties.

[1]  Benjamin Levrard,et al.  Is tidal heating sufficient to explain bloated exoplanets? Consistent calculations accounting for finite initial eccentricity , 2010, 1004.0463.

[2]  A. Claret,et al.  A new non-linear limb-darkening law for LTE stellar atmosphere models III - Sloan filters: Calculations for –5.0 ≤ log [M/H] ≤ +1, 2000 K ≤ T$\mathsf{_{eff}}$ ≤ 50 000 K at several surface gravities , 2004 .

[3]  R.G.West,et al.  WASP-25b: A 0.6M planet in the Southern hemisphere , 2010, 1009.5917.

[4]  M. Nagasawa,et al.  Formation of Hot Planets by a Combination of Planet Scattering, Tidal Circularization, and the Kozai Mechanism , 2008, 0801.1368.

[5]  UC Berkeley,et al.  HAT-P-12b: A LOW-DENSITY SUB-SATURN MASS PLANET TRANSITING A METAL-POOR K DWARF , 2009, 0904.4704.

[6]  John Asher Johnson,et al.  HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES , 2010, 1006.4161.

[7]  I. Hubeny,et al.  Possible Solutions to the Radius Anomalies of Transiting Giant Planets , 2006 .

[8]  Jean Manfroid,et al.  TRAPPIST: TRAnsiting Planets and PlanetesImals Small Telescope , 2011 .

[9]  Measurement of the Spin-Orbit Alignment in the Exoplanetary System HD 189733 , 2006, astro-ph/0609506.

[10]  R. Perna,et al.  OHMIC DISSIPATION IN THE ATMOSPHERES OF HOT JUPITERS , 2010, 1009.3273.

[11]  Sofia Randich,et al.  Time scales of Li evolution: A Homogeneous analysis of open clusters from ZAMS to late-MS , 2005 .

[12]  E. Agol,et al.  Analytic Light Curves for Planetary Transit Searches , 2002, astro-ph/0210099.

[13]  S. Barnes Accepted for publication in The Astrophysical Journal Ages for illustrative field stars using gyrochronology: viability, limitations and errors , 2022 .

[14]  Peter Bodenheimer,et al.  On the Tidal Inflation of Short-Period Extrasolar Planets , 2001 .

[15]  J. Valenti,et al.  Spectral Synthesis of TiO Lines , 1998 .

[16]  C. Murray,et al.  Solar System Dynamics: Expansion of the Disturbing Function , 1999 .

[17]  Ignasi Ribas,et al.  A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars , 2006, astro-ph/0605751.

[18]  R. G. West,et al.  Efficient identification of exoplanetary transit candidates from SuperWASP light curves , 2007, 0707.0417.

[19]  Gregory Laughlin,et al.  ON THE ANOMALOUS RADII OF THE TRANSITING EXTRASOLAR PLANETS , 2011, 1101.5827.

[20]  R. G. West,et al.  WASP-17b: AN ULTRA-LOW DENSITY PLANET IN A PROBABLE RETROGRADE ORBIT , 2009, 0908.1553.

[21]  R. G. West,et al.  WASP-12b: THE HOTTEST TRANSITING EXTRASOLAR PLANET YET DISCOVERED , 2008, 0812.3240.

[22]  Renata M. Wentzcovitch,et al.  Dissociation of MgSiO3 in the Cores of Gas Giants and Terrestrial Exoplanets , 2006, Science.

[23]  A. Cumming,et al.  OHMIC DISSIPATION IN THE INTERIORS OF HOT JUPITERS , 2012, 1207.3278.

[24]  A. Cameron,et al.  Are falling planets spinning up their host stars , 2011, 1103.3599.

[25]  L. Hebb,et al.  Improved parameters for the transiting hot Jupiters WASP-4b and WASP-5b , 2008, 0812.1998.

[26]  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.

[27]  G. Kov'acs,et al.  A box-fitting algorithm in the search for periodic transits , 2002, astro-ph/0206099.

[28]  R. G. West,et al.  WASP-19b: THE SHORTEST PERIOD TRANSITING EXOPLANET YET DISCOVERED , 2010, 1001.0403.

[29]  D. F. Gray,et al.  The Observation and Analysis of Stellar Photospheres , 2021 .

[30]  M. Livio,et al.  On the masses of the white dwarfs in cataclysmic variables , 1984 .

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

[32]  Douglas N. C. Lin,et al.  WASP-12b as a prolate, inflated and disrupting planet from tidal dissipation , 2010, Nature.

[33]  K. Heng,et al.  On the effects of clouds and hazes in the atmospheres of hot Jupiters: semi‐analytical temperature–pressure profiles , 2011, 1107.1390.

[34]  K. Menou,et al.  THREE-DIMENSIONAL ATMOSPHERIC CIRCULATION MODELS OF HD 189733b AND HD 209458b WITH CONSISTENT MAGNETIC DRAG AND OHMIC DISSIPATION , 2012, 1208.2274.

[35]  R. G. West,et al.  WASP-3b: a strongly irradiated transiting gas-giant planet , 2007, 0711.0126.

[36]  A. Gimenez,et al.  Accurate masses and radii of normal stars: modern results and applications , 2009, 0908.2624.

[37]  Don A. VandenBerg,et al.  The Victoria-Regina Stellar Models: Evolutionary Tracks and Isochrones for a Wide Range in Mass and Metallicity that Allow for Empirically Constrained Amounts of Convective Core Overshooting , 2006 .

[38]  D. B. McLaughlin Some results of a spectrographic study of the Algol system. , 1924 .

[39]  R. A. Rossiter On the detection of an effect of rotation during eclipse in the velocity of the brigher component of beta Lyrae, and on the constancy of velocity of this system. , 1924 .

[40]  Thierry Forveille,et al.  The SOPHIE search for northern extrasolar planets . I. A companion around HD 16760 with mass close to the planet/brown-dwarf transition , 2009 .

[41]  Jong-Hak Woo,et al.  Y2 Isochrones with an Improved Core Overshoot Treatment , 2004 .

[42]  John Southworth,et al.  Homogeneous studies of transiting extrasolar planets - III. Additional planets and stellar models , 2010, 1006.4443.

[43]  B. Militzer,et al.  SOLUBILITY OF WATER ICE IN METALLIC HYDROGEN: CONSEQUENCES FOR CORE EROSION IN GAS GIANT PLANETS , 2012 .

[44]  Joshua N. Winn,et al.  NEAR-INFRARED TRANSIT PHOTOMETRY OF THE EXOPLANET HD 149026b , 2009, 0902.1542.

[45]  R. P. Butler,et al.  OBLIQUITIES OF HOT JUPITER HOST STARS: EVIDENCE FOR TIDAL INTERACTIONS AND PRIMORDIAL MISALIGNMENTS , 2012, 1206.6105.

[46]  S. Baliunas,et al.  No Planet for Hd 166435 , 2022 .

[47]  The N2K Consortium. II. A Transiting Hot Saturn around HD 149026 with a Large Dense Core , 2005, astro-ph/0507009.

[48]  S. Cassisi,et al.  A Large Stellar Evolution Database for Population Synthesis Studies. I. Scaled Solar Models and Isochrones , 2004, astro-ph/0405193.

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

[50]  S. Seager,et al.  A Unique Solution of Planet and Star Parameters from an Extrasolar Planet Transit Light Curve , 2002, astro-ph/0206228.

[51]  D. W. Latham,et al.  HAT-P-32b AND HAT-P-33b: TWO HIGHLY INFLATED HOT JUPITERS TRANSITING HIGH-JITTER STARS , 2011, 1106.1212.

[52]  Konstantin Batygin,et al.  EVOLUTION OF OHMICALLY HEATED HOT JUPITERS , 2011, 1101.3800.

[53]  S. Tremaine,et al.  Submitted to ApJ Preprint typeset using L ATEX style emulateapj v. 10/09/06 SHRINKING BINARY AND PLANETARY ORBITS BY KOZAI CYCLES WITH TIDAL FRICTION , 2022 .

[54]  K.Horne,et al.  Factors affecting the radii of close-in transiting exoplanets , 2012, 1202.6199.

[55]  L. B. Lucy,et al.  Spectroscopic binaries with circular orbits , 1973 .

[56]  Tsevi Mazeh,et al.  Correcting systematic effects in a large set of photometric light curves , 2005, astro-ph/0502056.

[57]  R. G. West,et al.  An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b , 2009, Nature.

[58]  Shuo Kong,et al.  Inclination angle of the outflow in IRAS 05553+1631: a method to correct the projection effect , 2010, 1012.3268.

[59]  C. Moutou,et al.  Misaligned spin-orbit in the XO-3 planetary system?† , 2008, Proceedings of the International Astronomical Union.

[60]  James F. Kasting,et al.  A PHOTOCHEMICAL MODEL FOR THE CARBON-RICH PLANET WASP-12b , 2011, 1110.2793.

[61]  J. Fortney,et al.  The Interior Structure, Composition, and Evolution of Giant Planets , 2009, 0912.0533.

[62]  Tristan Guillot,et al.  Astronomy and Astrophysics Evolution of " 51 Peg B-like " Planets , 2001 .

[63]  Belgium,et al.  Evolution of asymptotic giant branch stars. II. Optical to far-infrared isochrones with improved TP- , 2007, 0711.4922.

[64]  F. Foucart,et al.  Evolution of spin direction of accreting magnetic protostars and spin-orbit misalignment in exoplanetary systems , 2010, Proceedings of the International Astronomical Union.

[65]  B. Smalley,et al.  Accurate fundamental parameters for 23 bright solar-type stars , 2010, 1002.4268.

[66]  Mark S. Marley,et al.  Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits , 2006 .

[67]  Jack J. Lissauer,et al.  The Effects of Post-Main-Sequence Solar Mass Loss on the Stability of Our Planetary System , 1998 .

[68]  Eric B. Ford,et al.  Improving the Efficiency of Markov Chain Monte Carlo for Analyzing the Orbits of Extrasolar Planets , 2005, astro-ph/0512634.

[69]  R. G. West,et al.  WASP-42 b and WASP-49 b: two new transiting sub-Jupiters , 2012, 1205.2757.

[70]  K.A.Alsubai,et al.  Qatar-1b: A hot Jupiter orbiting a metal-rich K dwarf star , 2010 .

[71]  Jonathan J. Fortney,et al.  THE HEAVY-ELEMENT MASSES OF EXTRASOLAR GIANT PLANETS, REVEALED , 2011, 1105.0024.

[72]  R. W. Noyes,et al.  A trend filtering algorithm for wide-field variability surveys , 2004 .

[73]  C. Moutou,et al.  The SOPHIE search for northern extrasolar planets. III. A Jupiter-mass companion around HD 109246 , 2010, 1006.4984.

[74]  William Reginald Stephen Garton,et al.  ABSORPTION SPECTRA OF Zn I, Cd I, AND Hg I IN THE VACUUM ULTRAVIOLET. , 1969 .

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

[76]  R. Paul Butler,et al.  On the Eccentricity of HD 209458b , 2005 .

[77]  Las Cumbres Observatory Global Telescope Network,et al.  PLANETARY CANDIDATES OBSERVED BY KEPLER. III. ANALYSIS OF THE FIRST 16 MONTHS OF DATA , 2012, 1202.5852.

[78]  Eva Villaver,et al.  Can Planets Survive Stellar Evolution? , 2007, astro-ph/0702724.

[79]  J. E. Pringle,et al.  Chaotic star formation and the alignment of stellar rotation with disc and planetary orbital axes , 2010 .

[80]  A. Collier Cameron,et al.  A fast hybrid algorithm for exoplanetary transit searches , 2006, astro-ph/0609418.

[81]  Paolo Conconi,et al.  Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series , 2012 .

[82]  N. Zakamska,et al.  Observational biases in determining extrasolar planet eccentricities in single‐planet systems , 2010, 1008.4152.

[83]  U. Kolb,et al.  PIRATE: A Remotely Operable Telescope Facility for Research and Education , 2011, 1108.4196.

[84]  I. Baraffe,et al.  Structure and evolution of super-Earth to super-Jupiter exoplanets - I. Heavy element enrichment in the interior , 2008, 0802.1810.

[85]  R. G. West,et al.  WASP-31b: A low-density planet transiting a metal-poor, late-F-type dwarf star , 2010, 1011.5882.

[86]  M. Skrutskie,et al.  The Two Micron All Sky Survey (2MASS) , 2006 .

[87]  Gilles Chabrier,et al.  Heat transport in giant (exo)planets: a new perspective , 2007 .

[88]  R. Perna,et al.  THE EFFECTS OF IRRADIATION ON HOT JOVIAN ATMOSPHERES: HEAT REDISTRIBUTION AND ENERGY DISSIPATION , 2012, 1201.5391.

[89]  P. Stetson DAOPHOT: A COMPUTER PROGRAM FOR CROWDED-FIELD STELLAR PHOTOMETRY , 1987 .

[90]  Benjamin F. Williams,et al.  THE ACS NEARBY GALAXY SURVEY TREASURY. IX. CONSTRAINING ASYMPTOTIC GIANT BRANCH EVOLUTION WITH OLD METAL-POOR GALAXIES , 2010, 1009.4618.

[91]  T. Barman,et al.  The physical properties of extra-solar planets , 2010, 1001.3577.

[92]  Eike W. Guenther,et al.  HD15082b, a short-period planet orbiting an A-star , 2011 .

[93]  T. Davis,et al.  The coronal X-ray - age relation and its implications for the evaporation of exoplanets , 2011, 1111.0031.

[94]  G. Laughlin,et al.  On the Radii of Extrasolar Giant Planets , 2003 .