K2-30b and K2-34b: two inflated hot-Jupiters around Solar-type stars

0.57 MB·

by  J. Lillo-Box

Astronomy&Astrophysicsmanuscriptno.TwoHotJupitersK2 (cid:13)cESO2016
May25,2016
K2-30b and K2-34b: two inflated hot-Jupiters
around Solar-type stars
J.Lillo-Box1,2,O.Demangeon3,A.Santerne4,3,S.C.C.Barros4,D.Barrado2,G.Hébrard5,6,H.P.Osborn7,
D.J.Armstrong7,12,J.-M.Almenara8,9,I.Boisse3,F.Bouchy3,10,D.J.A.Brown7,B.Courcol7,M.Deleuil3,
E.DelgadoMena4,R.F.Díaz7,J.Kirk7,K.W.F.Lam7,J.McCormac7,D.Pollacco7,A.Rajpurohit3,11,J.Rey10,
N.C.Santos4,13,S.G.Sousa4,M.Tsantaki4,P.A.Wilson5
1 EuropeanSouthernObservatory(ESO),AlonsodeCordova3107,Vitacura,Casilla19001,SantiagodeChile(Chile)
e-mail:[email protected]
6
2 Depto.deAstrofísica,CentrodeAstrobiología(CSIC-INTA),ESACcampus28692VillanuevadelaCañada(Madrid),Spain
1
3 AixMarseilleUniversité,CNRS,Laboratoired’AstrophysiquedeMarseilleUMR7326,13388,Marseille,France
0
4 InstitutodeAstrofísicaeCiênciasdoEspaço,UniversidadedoPorto,CAUP,RuadasEstrelas,PT4150-762Porto,Portugal
2
5 Institutd’AstrophysiquedeParis,UMR7095CNRS,UniversitéPierre&MarieCurie,98bisboulevardArago,75014Paris,France

y 6 ObservatoiredeHaute-Provence,Universitéd’Aix-Marseille&CNRS,04870Saint-Michell’Observatoire,France
a 7 DepartmentofPhysics,UniversityofWarwick,GibbetHillRoad,Coventry,CV47AL,UK
M 8 UniversitéGrenobleAlpes,IPAG,38000Grenoble,France
9 CNRS,IPAG,38000Grenoble,France
4 10 ObservatoireAstronomiquedel’UniversitédeGenève,51chemindesMaillettes,1290Versoix,Switzerland
2 11 AstronomyandAstrophysicsDivision,PhysicalResearchLaboratory,Ahmedabad380009,India
12 ARC,SchoolofMathematics&Physics,Queen’sUniversityBelfast,UniversityRoad,BelfastBT71NN,UK
] 13 Depto.deFísicaeAstronomia,FaculdadedeCiências,UniversidadedoPorto,RuaCampoAlegre,4169-007Porto,Portugal
P
E May25,2016
.
h
p ABSTRACT
-
o Wereportthediscoveryofthetwohot-JupitersK2-30bandK2-34b.Thetwoplanetsweredetectedtransitingtheirmain-sequence
r starswithperiods∼4.099and∼2.996days,incampaigns4and5oftheextensionoftheKeplermission,K2.Subsequentground-
t
s basedradialvelocityfollow-upwithSOPHIE,HARPS-NandCAFEestablishedtheplanetarynatureofthetransitingobjects.We
a analysedthetransitsignal,radialvelocityandspectralenergydistributionsofthetwosystemstocharacterizetheirproperties.Both
[ planets(K2-30bandK2-34b)arebloatedhot-Jupiters(1.20R and1.22R )aroundrelativelybright(V = 13.5andV = 11.5),
Jup Jup
slow rotating main-sequence (G8 and F9) stars. Thus, these systems are good candidates for detecting the Rossiter-MacLaughlin
2 effecttomeasuretheirobliquityandforatmosphericstudies.
v
5 Keywords. Planetsandsatellites:detection,gaseousplanets;Techniques:radialvelocities,highangularresolution,photometric.
3
6
7
1. Introduction didateshavestellarcompanionscloserthan3arcsec.Thus,both
0
high-resolutionimagesandradialvelocity(RV)dataareneeded.
.
1TheextensionoftheKeplermission(K2,Howelletal.2014)is
The currently known extrasolar planets show an interesting
0photometricallymonitoringdifferentfieldsalongtheeclipticfor
population of close-in (a < 0.1 au) gaseous planets, known as
6∼80daytimespans.Despitetheshortertimespanandtheslightly
hot-Jupiters (hereafter HJ), with a maximum frequency at a 5-
1
lower photometric precision with respect to the prime mission,
: dayperiod(Santerneetal.2015b).Thedetectionandfullchar-
vseveral tens of extrasolar planets have been detected and char- acterizationofthesesystemshasbecomecrucialtounderstand-
iacterizedsofar.Theseplanetscoverawiderangeofproperties,
X ing early migration processes as well as planet-star and planet-
from disintegrating Neptune-size objects (Sanchis-Ojeda et al.
planetinteractions.Thesearethebesttargetstostudythesepro-
r2015)throughvalidatedEarth-sizeplanets(e.g.Crossfieldetal.
a cessesbecausetheirconsequencesareeasilydetectablefromthe
2015; Petigura et al. 2015) to resonant multi-planetary systems
ground.Forinstance,HJswerefoundtobemostlysolitary(Stef-
(Armstrongetal.2015b;Barrosetal.2015).
fen et al. 2012), with no other planets in the system. This was
Severalworkshaveprovidedplanetcandidatesbasedonin- explainedbypossiblesuppressionofrockyplanetformationdue
dependent analysis of the light curves (e.g., Foreman-Mackey to the inward migration of the HJ early in the evolution of the
et al. 2015). However, as in the prime part of the mission, any system (e.g., Armitage 2003). However, the detection of inner
candidate requires follow-up observations to unveil its nature. andouterplanetstotheHJWASP-47busingK2(Beckeretal.
Due to the large Kepler pixel size (around 4×4 arcsec), con- 2015) has challenged this scenario. Also, measuring the spin-
taminant sources can lie within the photometric aperture. Sev- orbit angle provides hints on the migration history of the sys-
eral high-spatial resolution follow-up surveys were carried out tem (Morton & Johnson 2011) and this angle has been deter-
fortheprimemission(e.g.Lillo-Boxetal.2012,2014b;Adams minedformanyHJssofar(e.g.,Winnetal.2005).Additionally,
etal.2012;Lawetal.2014)concludingthat20-40%ofthecan- manyHJsarefoundtobebloated.Thesourceofsuchinflation
Articlenumber,page1of6
A&Aproofs:manuscriptno.TwoHotJupitersK2
is still not well understood, and several mechanisms have been 2.3. High-resolutionspectroscopy
proposed (e.g., Batygin & Stevenson 2010; Showman & Guil-
WeobservedthetwotransitedstarswithHARPS-N(Cosentino
lot2002).Butnonecanexplaintheinflationbyitself.Ontopof
et al. 2012) at the Telescopio Nazionale Galileo (TNG, Spain)
this, transiting HJs currently represent the best chance to study
andSOPHIE(Bouchyetal.2013)attheObservatoiredeHaute-
exoplanetatmospheres,withhighprecisionlightcurvesalsoal-
Provence(OHP,France).TwoadditionalepochsforK2-34were
lowingphasecurvestudies.
obtainedwithCAFE(Aceitunoetal.2013)atthe2.2mtelescope
Hence, a full characterization of a large population of HJs
oftheCalarAltoObservatory(CAHA,Spain).Thethreeinstru-
is necessary to analyze the migration and formation history of
ments are fiber-fed high-resolution echelle spectrographs with
these systems as well as study the planet-planet and planet-star
resolving powers of R∼40000 (SOPHIE in the high-efficiency
interactions.Wehaveuseddatafromdifferentfacilitiestoiden-
mode), R = 110000 (HARPS-N) and R = 63000 (CAFE) and
tifyandcharacterizetheextrasolarplanetsK2-34bandK2-30b,
having no movable pieces. They are located in isolated cham-
twoinflatedhot-JupitersaroundSolar-likestars.Inthispaperwe
berstoimprovethestability.SOPHIEandHARPS-Narestabi-
detailtheobservations,datareduction,analysisandconclusions
lizedintemperatureandpressurewhiletheseambientconditions
aboutthesesystems.
are simply monitored in the case of CAFE to check for possi-
ble RV drifts. In the three cases, the data was reduced with the
corresponding online pipelines2. The RV is subsequently com-
2. Observationsanddatahandling
puted by determining the weighted cross-correlation function
(CCF) between the spectra and a G2V binary mask3 (Baranne
2.1. K2photometry
et al. 1996; Pepe et al. 2002). SOPHIE data were corrected for
ThestarK2-30(EPIC210957318,03:29:22.07+22:17:57.9)was thechargetransferinefficiencypresentinthecharge-couplede-
observedbyK2duringitscampaign4,between2015-02-07and vice of the instrument (Santerne et al. 2012). The RVs were
2015-04-23.K2-34(EPIC212110888,08:30:18.91+22:14:09.3) alsocorrectedforinstrumentaldriftsusingtheRVstandardstar
belongstofield-of-view5,photometricallymonitoredbyK2be- HD56124 observed during the same nights and following the
tween2015-04-27and2015-07-10.Thedatawasreducedusing prescriptionsinSanterneetal.(2014).CAFERVswerealsocor-
both the Warwick (Armstrong et al. 2015a) and the LAM- K2 rected using observations of the same standard star during the
(Barrosetal.2015)pipelines.Thedetrendeddata(seeTables1 nights.
and 2) show 1.9% and 0.8% dimmings every 4.099 and 2.996 ForK2-30,sevenepochswereobtainedwithHARPS-Ndur-
daysforK2-30andK2-34,respectively(seeFigs.1and 2). ingfourconsecutivenights(4-7January,2016)havingasignal-
to-noiseratioperpixelat550nm(S/N)atthelevelof15-30,and
fiveepochswereobtainedwithSOPHIEinthesubsequentseven
2.2. High-spatialresolutionimaging nights(8-13January,2016)withS/Nof10-25.Thisprovidesa
Weobtainedahigh-spatialresolutionimageofK2-34andK2-30 time span of ten days for this ∼ 4-day period planet. For K2-
withtheinstrumentAstraLuxatthe2.2mtelescopeinCalarAlto 34,weobtained3epochswithHARPS-Non4-7January2016
Observatory(Spain).Weusedthelucky-imagingtechnique,ob- (S/Nof16-50),4epochswithSOPHIEon10-15January2016
taining 90000 frames (45000 frames), each with an exposure (S/N of 27-40), and two epochs with CAFE on 24-25 of De-
time of 0.040 s (0.080 s) for K2-34 (K2-30). using the max- cember 2015 (S/N of 11-13). This encompasses a 22-day time
imum gain setting. The images were reduced with the obser- span for this ∼3-day period planet. The derived RV values are
vatory pipeline, which performs basic reduction of the individ- showninTables3and4.Inbothcases,theradialvelocityvari-
ualframes,selectstheframeswiththebestStrehlratios(Strehl ations show no significant correlation with the bisector values,
1902),alignsthoseframesandcombinesthemtoprovideafinal indicating that they do not originate from blended (undetected)
near-diffractionlimitedimage.Inthiscase,weselectedthebest stars.Wecalculatedtheprojectedrotationalvelocityofthestar
10%offrames,whichtranslatesintoaneffectiveexposuretime usingthecorrespondingCCFfollowingBoisseetal.(2010),see
of360s.Nocompanionisdetectedwithinthesensitivitylimits Table7.
oftheimages.Thesensitivitycurveineachcasewasobtainedby
followingtheprescriptionsinLillo-Boxetal.(2014a),simulat-
ingartificialstarsatdifferentpositionsinthereducedimageand 3. Results
different contrast magnitudes and counting how many of them 3.1. Stellarproperties
arerecoveredwitha5σsignal-to-noise.Insummary,theimage
wouldhaveallowedustodetectcompanionswithcontrastmag- ThespectralanalysiswasperformedontheHARPS-Ndata.For
nitudes brighter than 3.5 mag (3.7 mag) at 0.5 arcsec, 5.3 mag K2-30 the seven spectra were combined, with the final spec-
(5.0 mag) at 1 arcsec and 8 mag (6.0 mag) at 2 arcsec for K2- trum reaching a S/N of 56. In the case of K2-34, we used a
34(K2-30).Sincenocompanionisdetectedwithintheselimits, single spectrum with S/N of 50. The spectroscopic parameters
weassumethatK2-34andK2-30areisolatedandthattheirlight werederivedwiththeARES+MOOGmethod(seeSousa2014,
curvesarenotpollutedbyothersources1. for details) which is based on the measurement of equivalent
widthsofironlineswithARES(Sousaetal.2015).Thismethod
1 Afterthesubmissionofthispaper,webecameawareofthesubmitted hasbeenusedtoderivehomogeneousparametersforplanet-host
publicationbyHiranoetal.(2016)whofoundafaintcompaniontoK2- stars(e.g.,Santosetal.2013).Thederivedproperties(Teff,logg,
34at361.3±3.5maswith∆m =6.19±0.11.Thissourceisbelowour and [Fe/H]) for this G8V (K2-30) and F9V (K2-34) stars were
H
detectionlimitsbutduetoitsfaintnessithasanegligibleimpactonthe usedaspriorsforthejointanalysisofthedata(seeSect.3.2)and
photometric analysis. The maximum contrast for a blended eclipsing are provided in Table 5. Additionally, we also determined the
binarytobeabletomimicthedetectedtransitofK2-34intheKepler
bandwouldbe∆mmax = 5.2mag.Consequently,itisnotpossiblethat 2 FordetailsontheCAFEpipelinesee
Kep
theclosecompanionisthesourceoftheeclipse.Hence,inpractice,we http://www.caha.es/CAHA/Instruments/CAFE/softw.html
cantreatthesystemasbeingisolated. 3 InthecaseofCAFE,seesection2.3Lillo-Boxetal.(2015).
Articlenumber,page2of6
Lillo-Boxetal.:K2-30bandK2-34b:twoinflatedhot-JupitersaroundSolar-typestars
lithiumabundanceforthesehoststars.Wefoundanabundance eachinstrumentandaRVoffsetbetweenSOPHIEandtheother
ofA(Li)=2.16±0.2dexforK2-34(Teff =6130±50K)andan instrumentsused.AjitterisalsoaddedfortheSEDanalysis.For
upperlimitofA(Li)< 0.9dexforK2-30(Teff = 5585±38K). K2-34,duetothelownumberofRVdatapoints,weassumeda
These abundances provide an estimated lower limit for the age circular orbit5. This assumption is justified by the short period
of both targets of 2 Gyr when compared to the abundances of andcircularizationmechanisms.Intotal,20freeparametersare
members of the NGC752 (Sestito et al. 2004) or M67 cluster fitted for both systems. Uniform priors are used for all free pa-
(Pasquinietal.2008). rametersexceptforthestellarvaluesthatwereconstrainedtothe
resultsofthespectralanalysis(seeSect.3.1).Thelistofpriorsis
showninTable5.Weran20chainsof3×105iterationsrandomly
3.2. Jointanalysisofthedata
drawnfromthejointpriordistribution.Allchainsconvergedto-
WeusedthePASTISsoftware(Díazetal.2014;Santerneetal. wardthesamesolutionwhichisassumedtobetheglobalmax-
2015a) to perform a joint analysis of the K2 light curve, radial imum.Inordertoobtainthefinalsolutionanditsuncertainties,
velocities,andmagnitudesofthetwotargets.Thetransitsignals weremovedtheburn-inphaseofeachchainandthinnedthemby
weremodeled4 usingamodifiedversionoftheJKTEBOPcode computing their maximum correlation length. At this point we
(Southworth2011,andreferencestherein)andaKeplerianorbit merged all of them to compute a well-sampled and clean pos-
wasfittedtotheRVdata.Thespectralenergydistribution(SED, teriordistributionhavingmorethan2000independentsamples.
Table6)wasmodeledwiththeBT-SETTLlibrary(Allard2014) The median values are presented in Table 7 together with the
andthestellarparameterswerederivedusingtheDartmouthstel- 15.7% and 84.3% percentiles of the marginalized distributions.
larevolutiontracks(Dotteretal.2008). Inthetablewealsopresentotherparametersderivedfromthose
fittedbythemodel(e.g.,planetmass,planetradius,stellarmass,
etc.).ThedataandbestfitmodelsarepresentedinFigs1,2and
4.
1.000
0.995 1.002
x
u
fl
ve 1.000
ati0.990
el
R x0.998
u
fl
0.985 ve
ati0.996
el
R
O-C[ppt]−1010.03 0.02 0.01 0.00 0.01 0.02 0.03 0.994
− − − 0.992
Orbitalphase
O-Cppm] 000...505
35.60 [− 0.03 0.02 0.01 0.00 0.01 0.02 0.03
− − −
Orbitalphase
1m.s]−35.55 46.6
k
[
dialvelocity3355..4550 1[km.s]−4466..45
a y
R cit46.3
35.40 SOPHIE HARPS-N velo
O-C1m.s]− 55000 Radial46.2
[− 0.0 0.2 0.4 0.6 0.8 1.0 46.1
CAFE SOPHIE HARPS-N
Orbitalphase
Fig.1.ResultsofthejointanalysiswithPASTISforK2-30,including O-C1m.s]− 55000
theprimarytransit(toppanel)andradialvelocity(bottompanels).The [− 0.0 0.2 0.4 0.6 0.8 1.0
Orbitalphase
finalmodelsareshownwithsolidlinesandtheresidualsofthedataare
presentedinthelowerpartofeachpanel. Fig.2.ResultsofthejointanalysiswithPASTISforK2-34.Samesym-
bolsasinFig.1.
We performed a statistical analysis using Markov Chain
Monte-Carlo (MCMC) algorithms. The model is described by
sixfreeparametersforthehoststar(Teff,logg,[Fe/H],systemic
radialvelocityV ,interstellarextinctionE(B−V),anddistance
sys 4. Discussion
d)andsevenfreeparametersforthetransit(period P,epochof
firsttransitT ,radialvelocityamplitude K,radiusratioR /R , The combination of different datasets for K2-30b and K2-34b
0 p (cid:63)
orbital eccentricity e, inclination i, and argument of periastron establishestheplanetarynatureofthetransitingobjectsaround
ω). For the light curve, we also fit for an additional source of
white noise, the out-of-transit flux level, and the level of con- 5 Wetestedthenon-circularhypothesisandcomparedthebayesianin-
tamination. For the RV, we additionally fit for a jitter term for formationcriterion(BIC,see,forinstance,Schwarz1978;Smithetal.
2009)ofthetwomodels.Asexpected,theresultsprovidestrongevi-
4 Models are numerically integrated over the Kepler exposure time denceforthecircularmodelgiventhecurrentdata,withaBICdiffer-
withanoversamplingfactorof10. enceof2infavorofthecircular(simpler)hypothesis.
Articlenumber,page3of6
A&Aproofs:manuscriptno.TwoHotJupitersK2
twomain-sequencestars(G8VandF9V,respectively)observed 2.0
by K2. The analysis of the data indicates that both systems
are composed of single giant (1.197±0.052 R for K2-30 and
Jup
1.217±0.053 R for K2-34) planets in close-in orbits around 1.5
Jup
theirmain-sequencestars.
planIent tihseFca=se4o.2f4K±2-03.307, t×he10in8seorlgatiso−n1 cflmux−2r.eTcehiivseids bsiygntihfe- R)Jup1.0
icantly larger than the empirical cut off limit derived by De- R (p
mory & Seager (2011) for a planet to have an inflated radius
(F > 2.08 × 108 erg s−1 cm−2). Assuming a Bond albedo 0.5
A = 0 and a complete redistribution of the tidal heating along
the planet, its expected radius according to Eq. 9 in Enoch
etal.(2012)wouldbe0.777±0.014RJup6.AccordingtoWeiss 0.1005 106 107 108 109 1010
et al. (2013) the mass-radius-insolation flux relation provides Insolation Flux (erg.s−1.cm−2)
an expected radius for this planet of 1.151 ± 0.010 R . In
Jup Fig.3.Insolationfluxandplanetradiusforallextrasolarplanetswith
the case of K2-34b, the planet receives an insolation flux of
F =1.768±0.14×109ergs−1cm−2.Thisisoneorderofmagni- knownradius,Teffandsemi-majoraxis.DatatakenfromtheTheExtra-
solarPlanetEncyclopedia.Thetwohot-Jupitersfoundinthisworkare
tudelargerthantheabovementionedcutofflimitderivedbyDe-
markedasfilledcircles(K2-34inredandK2-30inblue).Theexpected
mory&Seager(2011).TheexpectedradiusaccordingtoEnoch radius-insolationfluxdependencyforeachsystemaccordingtoWeiss
etal.(2012)wouldbe0.993±0.016RJupandtheexpectedradius etal.(2013)isshownasdashedred(K2-34)anddash-dotblue(K2-30)
fromWeissetal.(2013)is1.267±0.010R . lines.
Jup
Inbothcases,theplanetshavecomparableradiitothatpre-
dictedbyempiricalcalibrations(seeFig.3).Althoughcompared
Acknowledgements. J.L-B acknowledges financial support from the Marie
tothevaluespredictedbyWeissetal.(2013)theyarecompati-
Curie Actions of the European Commission (FP7-COFUND) and the Span-
blewithin1σwithbeinginflatedduetothehighstellarinsola- ish grant AYA2012- 38897-C02-01. O.D. acknowledges support by CNES
tionflux,bothareclearlylarger(>3σ)thanthepredictedvalue through contract 567133. A.S. is supported by the European Union under a
by Enoch et al. (2012). It is known that high stellar irradiance Marie Curie Intra-European Fellowship for Career Development with refer-
ence FP7-PEOPLE-2013-IEF, number 627202. D.J.A. and D.P acknowledge
canexplaintheinflationoftheclose-inJupiterplanetswithradii
fundingfromtheEuropeanUnionSeventhFrameworkprogramme(FP7/2007-
upto∼1.2RJup (Guillot&Showman2002).However,thiscan- 2013) under grant agreement No. 313014 (ETAEARTH). J-M.A. acknowl-
not explain larger radii, and so other mechanisms must play a edges funding from the European Research Council under the ERC Grant
role(e.g.,Bodenheimeretal.2001;Batygin&Stevenson2010; Agreementn.337591-ExTrA.P.A.WacknowledgesthesupportoftheFrench
Chabrier & Baraffe 2007). The small (statistically not signifi- AgenceNationaledelaRecherche(ANR),underprogramANR-12-BS05-0012
"Exo-Atmos". AS, SCCB, EDM, NCS, SS, and MT acknowledge support by
cant) eccentricity found in K2-30 could possibly indicate some
Fundação para a Ciência e a Tecnologia (FCT) through the research grants
tidalheating,butothermechanismscannotberejected. UID/FIS/04434/2013(POCI-01-0145-FEDER-007672)andprojectPTDC/FIS-
In this paper, we have characterized two HJs. They show AST/1526/2014. NCS, SGS, and SCCB acknowledge the support from FCT
throughInvestigadorFCTcontractsofreferenceIF/00169/2012,IF/00028/2014,
bloated radii possibly due to the large stellar insolation that
and IF/01312/2014, respectively, and POPH/FSE (EC) by FEDER funding
they are receiving from their host. However, other possible
through the program "Programa Operacional de Factores de Competitividade
mechanisms such as tidal heating may be playing a role. -COMPETE".EDMacknowledgesthesupportfromFCTintheformofthe
Since the hosts are bright (V = 11.5 for K2-34 and V = 13.5 grant SFRH/BPD/76606/2011. This publication is based on observations col-
lectedwiththeNASAsatelliteKepler,withtheSOPHIEspectrographatOHP
for K2-30) and the planets are inflated, they are amenable
(CNRS,France),HARPS-N(LaPalma,Spain),andCAFEandAstraLuxatCalar
for atmospheric characterization either from the ground or
Alto Observatory (Spain). This publication makes use of data products from
from space. As they transit, they are also good candidates for theWide-fieldInfraredSurveyExplorer,whichisajointproject(UCLA/JPL)
the detection of the Rossiter-MacLaughlin effect to infer the fundedbyNASA.ThisresearchmadeuseoftheAAVSOPhotometricAll-Sky
spin-orbit angle and study the evolutionary history of these Survey,fundedbytheRobertMartinAyersSciencesFund.
systems. From the derived parameters, the amplitude of this
effect should be around 60 m/s and 40 m/s for K2-30 and
K2-34, respectively. Future searches for additional bodies will References
be interesting to unveil planet-planet interactions during the
Aceituno,J.,Sánchez,S.F.,Grupp,F.,etal.2013,A&A,552,A31
onsetoftheplanetarysystems.
Adams,E.R.,Ciardi,D.R.,Dupree,A.K.,etal.2012,AJ,144,42
Allard,F.2014,inIAUSymposium,Vol.299,IAUSymposium,ed.M.Booth,
Note: After the submission of this paper, we become aware of B.C.Matthews,&J.R.Graham,271–272
twootherpublicationsrelatedtothetwotargetsanalyzedinthis Armitage,P.J.2003,ApJ,582,L47
Armstrong,D.J.,Kirk,J.,Lam,K.W.F.,etal.2015a,A&A,579,A19
work. Hirano et al. (2016) analyzed the K2-34 system, finding
Armstrong,D.J.,Santerne,A.,Veras,D.,etal.2015b,A&A,582,A33
goodagreementintheparametersdirectlyderivedfrommodel-
Baranne,A.,Queloz,D.,Mayor,M.,etal.1996,A&AS,119,373
ingtheobservations.Duetosmalldifferencesinthedetermined Barros,S.C.C.,Almenara,J.M.,Demangeon,O.,etal.2015,MNRAS,454,
stellarproperties,someabsolutephysicalandorbitalparameters 4267
disagree by a small percentage. Johnson et al. (2016) analyzed Batygin,K.&Stevenson,D.J.2010,ApJ,714,L238
Becker,J.C.,Vanderburg,A.,Adams,F.C.,Rappaport,S.A.,&Schwengeler,
K2-30andtheirresultsaremainlyinagreementwithours.Some
H.M.2015,ApJ,812,L18
parametersarestilldifferentbyasmallpercentagebutthiscould Bodenheimer,P.,Lin,D.N.C.,&Mardling,R.A.2001,ApJ,548,466
beduetotheirassumptionofacircularorbitaswellasadifferent Boisse,I.,Eggenberger,A.,Santos,N.C.,etal.2010,A&A,523,A88
approachtothecalculationofthestellarparameters. Bouchy,F.,Díaz,R.F.,Hébrard,G.,etal.2013,A&A,549,A49
Chabrier,G.&Baraffe,I.2007,ApJ,661,L81
Cosentino,R.,Lovis,C.,Pepe,F.,etal.2012,inSocietyofPhoto-OpticalInstru-
6 Largeralbedoswouldimplysmallerexpectedplanetaryradiussothis mentationEngineers(SPIE)ConferenceSeries,Vol.8446,1
canbeconsideredasanupperlimit. Crossfield,I.J.M.,Petigura,E.,Schlieder,J.E.,etal.2015,ApJ,804,10
Articlenumber,page4of6
Lillo-Boxetal.:K2-30bandK2-34b:twoinflatedhot-JupitersaroundSolar-typestars
Table 1. Normalized detrended K2 light curve of K2-30 Table3.RadialvelocitydataforK2-30.
(EPIC210957318, see Sect. 2.1). The complete version of this
tableisavailableonlineintheCDS.
MBJD(days) RV(km/s) BIS(m/s) FWHM(km/s) Instrument
392.35938 35.5624±0.0043 -39.8±6.5 6.8842±0.0087 HARPS-N
BJD-2400000(days) Flux Fluxunc 392.57382 35.5504±0.0055 -18.9±8.2 6.8885±0.0109 HARPS-N
2457067.684383 1.000706 0.000103 393.33790 35.5809±0.0066 -3.2±10.0 6.8780±0.0133 HARPS-N
2457067.704815 0.999879 0.000103 393.47098 35.6069±0.0056 -37.6±8.4 6.8795±0.0111 HARPS-N
394.35486 35.6925±0.0042 -32.3±6.4 6.8701±0.0085 HARPS-N
2457067.725247 0.999752 0.000103
394.54090 35.7050±0.0054 -45.8±8.1 6.8717±0.0108 HARPS-N
2457067.745679 0.999817 0.000103
395.41956 35.6694±0.0165 3.9±24.7 6.8693±0.0329 HARPS-N
2457067.766111 0.999762 0.000103 396.44205 35.493±0.042 -24.5±75.1 9.682±0.104 SOPHIE
... ... ... 398.39484 35.582±0.010 -35.3±18.2 9.523±0.025 SOPHIE
399.41136 35.554±0.038 -18.1±67.9 9.415±0.094 SOPHIE
Table 2. Normalized detrended K2 light curve of K2-34 400.38519 35.435±0.019 -47.5±33.5 9.517±0.046 SOPHIE
(EPIC212110888, see Sect. 2.1). The complete version of this 401.35244 35.448±0.016 -22.0±29.3 9.572±0.040 SOPHIE
tableisavailableonlineintheCDS. 402.34190 35.553±0.011 -2.7±19.6 9.540±0.027 SOPHIE
404.43149 35.436±0.019 -11.0±34.0 9.591±0.047 SOPHIE
BJD(days) Flux Fluxunc Notes.MBJD=ModifiedBarycentricJulianDate(BJD-2457000)
2457139.630908 0.999991 0.000042
2457139.651340 0.999988 0.000042 Table4.RadialvelocitydataforK2-34.
2457139.671772 0.999930 0.000042
2457139.692204 0.999910 0.000042 MBJD(days) RV(km/s) BIS(m/s) FWHM(km/s) Instrument
2457139.712636 1.000159 0.000042 381.59795 45.863±0.040 -70±65 10.597±0.080 CAFE
382.62804 46.167±0.049 -178±70 10.841±0.110 CAFE
... ... ...
392.60905 46.5458±0.0034 35.3±5.1 9.5015±0.0069 HARPS-N
393.50729 46.2009±0.0133 40.7±19.9 9.4696±0.0266 HARPS-N
394.61995 46.4477±0.0138 36.6±20.8 9.4864±0.0277 HARPS-N
Cutri,R.M.,,,&etal.2013,VizieROnlineDataCatalog,2328 398.43529 46.490±0.018 11±32 11.395±0.044 SOPHIE
Demory,B.-O.&Seager,S.2011,ApJS,197,12
399.44751 46.136±0.018 -17±32 11.437±0.045 SOPHIE
Díaz,R.F.,Almenara,J.M.,Santerne,A.,etal.2014,MNRAS,441,983
399.68876 46.109±0.014 51±25 11.554±0.035 SOPHIE
Dotter,A.,Chaboyer,B.,Jevremovic´,D.,etal.2008,ApJS,178,89
Enoch,B.,CollierCameron,A.,&Horne,K.2012,A&A,540,A99 403.49977 46.328±0.019 16±33 11.367±0.046 SOPHIE
Foreman-Mackey,D.,Montet,B.T.,Hogg,D.W.,etal.2015,ApJ,806,215
Notes.MBJD=ModifiedBarycentricJulianDate(BJD-2457000)
Guillot,T.&Showman,A.P.2002,A&A,385,156
Hirano,T.,Nowak,G.,Kuzuhara,M.,etal.2016,ArXive-prints
Howell,S.B.,Sobeck,C.,Haas,M.,etal.2014,PASP,126,398 Table6.Photometryusedtoforthespectralenergydistributionanalysis
Johnson,M.C.,Gandolfi,D.,Fridlund,M.,etal.2016,ArXive-prints ofK2-30andK2-34
Kipping,D.M.2013,MNRAS,434,L51
Law,N.M.,Morton,T.,Baranec,C.,etal.2014,ApJ,791,35
Band K2-30 K2-34
Lillo-Box,J.,Barrado,D., Moya,A.,etal.2014a,A&A,562,A109
Lillo-Box,J.,Barrado,D.,&Bouy,H.2012,A&A,546,A10 Johnson-V 13.53±0.039 11.548±0.057
Lillo-Box,J.,Barrado,D.,&Bouy,H.2014b,A&A,566,A103 Johnson-B 14.506±0.030 12.429±0.033
Lillo-Box,J.,Barrado,D.,Santos,N.C.,etal.2015,A&A,577,A105
g(cid:48) - 11.892±0.119
Morton,T.D.&Johnson,J.A.2011,ApJ,729,138
Pasquini,L.,Biazzo,K.,Bonifacio,P.,Randich,S.,&Bedin,L.R.2008,A&A, r(cid:48) 13.184±0.042 11.389±0.026
489,677 i(cid:48) 12.819±0.046 11.264±0.038
Pepe,F.,Mayor,M.,Galland,F.,etal.2002,A&A,388,632
2MASS-J 11.632±0.019 10.528±0.025
Petigura,E.A.,Schlieder,J.E.,Crossfield,I.J.M.,etal.2015,ApJ,811,102
Sanchis-Ojeda,R.,Rappaport,S.,Pallé,E.,etal.2015,ArXive-prints 2MASS-H 11.190±0.016 10.258±0.022
Santerne,A.,Díaz,R.F.,Almenara,J.-M.,etal.2015a,MNRAS,451,2337 2MASS-Ks 11.088±0.020 10.193±0.017
Santerne,A.,Díaz,R.F.,Moutou,C.,etal.2012,A&A,545,A76
WISE-W1 11.016±0.023 10.174±0.023
Santerne,A.,Hébrard,G.,Deleuil,M.,etal.2014,A&A,571,A37
Santerne,A.,Moutou,C.,Tsantaki,M.,etal.2015b,ArXive-prints WISE-W2 11.058±0.021 10.207±0.020
Santos,N.C.,Sousa,S.G.,Mortier,A.,etal.2013,A&A,556,A150 WISE-W3 11.067±0.161 10.159±0.169
Schwarz,G.1978,AnnalsofStatistics,6,461
Sestito,P.,Randich,S.,&Pallavicini,R.2004,A&A,426,809 Notes.Opticalmagnitudes(Johnson-V,Johnson-B,g(cid:48),r(cid:48),andi(cid:48))were
Showman,A.P.&Guillot,T.2002,A&A,385,166
obtainedfromtheAPASSdatabase.Infraredvalueswereobtainedfrom
Smith,R.,Churcher,L.J.,Wyatt,M.C.,Moerchen,M.M.,&Telesco,C.M.
Cutrietal.(2013).
2009,A&A,493,299
Sousa,S.G.2014,ArXive-prints
Sousa,S.G.,Santos,N.C.,Adibekyan,V.,Delgado-Mena,E.,&Israelian,G.
2015,A&A,577,A67
Southworth,J.2011,MNRAS,417,2166
Steffen,J.H.,Ragozzine,D.,Fabrycky,D.C.,etal.2012,Proceedingsofthe
NationalAcademyofScience,109,7982
Strehl,K.1902,AstronomischeNachrichten,158,89
Weiss,L.M.,Marcy,G.W.,Rowe,J.F.,etal.2013,ApJ,768,14
Winn,J.N.,Noyes,R.W.,Holman,M.J.,etal.2005,ApJ,631,1215
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A&Aproofs:manuscriptno.TwoHotJupitersK2
Table5.ListoffreeparametersusedinthePASTISanalysisofthelightcurves,radialvelocitiesandSEDwiththeirassociatedprior.
Parameter K2-30 K2-34
Orbitalparameters
OrbitalperiodP[d] N(4.09803;1×10−3) N(2.996;1×10−3)
EpochoffirsttransitT [BJD ]-2450000 N(7063.826;0.1) N(7141.35;0.1)
0 TDB
Orbitaleccentricitye β(0.867;3.03) 0(fixed)
Argumentofperiastronω[◦] U(0;360) –
Inclinationi[◦] S(70;90) S(70;90)
Planetaryparameters
RadialvelocityamplitudeK [m/s] U(0;1000) U(0;1000)
Planet-to-starradiusratioa/R U(0;0.5) U(0;0.5)
(cid:63)
Stellarparameters
EffectivetemperatureTeff [K] N(5573;38) N(6139;50)
Surfacegravitylogg[g/cm2] N(4.32;0.20) N(4.07;0.21)
Ironabundance[Fe/H][dex] N(0.14;0.03) N(0.11;0.04)
ReddeningE(B-V)[mag] U(0;1) U(0;1)
SystemicradialvelocityV [km/s] U(−100,100) U(−100,100)
sys
DistancetoEarthd[pc] P(2;10;1000) P(2;10;1000)
Linearlimbdarkeningcoefficientua U(0,1.2) U(0,1.2)
Quadraticlimbdarkeningcoefficientub U(0,1.2) U(0,1.2)
Instrumentalparameters
CAFEradialvelocityjitterσ [m/s] – U(0;100)
RV,CAFE
SOPHIEradialvelocityjitterσ [m/s] U(0;100) U(0;100)
RV,SOPHIE
HARPS-Nradialvelocityjitterσ [m/s] U(0;100) U(0;100)
RV,HARPS−N
CAFE–SOPHIEradialvelocityoffset∆RV [m/s] U(−1000;1000) U(−1000;1000)
S,CAFE
HARPS-N–SOPHIEradialvelocityoffset∆RV [m/s] U(−1000;1000) U(−1000;1000)
S,H−N
SEDjitterσ [mag] U(0;1) U(0;1)
SED
Notes.N(µ;σ2)isanormaldistributionwithmeanµandwidthσ2,U(a;b)isauniformdistributionbetweenaandb,S(a,b)isasinedistribution
betweenaandb,β(a;b)isaBetadistributionwithparametersaandb,andP(n;a;b)isapower-lawdistributionofexponentnbetweenaandb.
References.ThechoiceofpriorfortheorbitaleccentricityisdescribedinKipping(2013).
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A&Aproofs:manuscriptno.TwoHotJupitersK2
Table7.Hoststar,planetandorbitalparametersinferredfromthejoint
analysisofthedata.Uncertaintiesrepresentthe15.7%and84.3%per-
centilesofthemarginalizedposteriordistribution 10−14
1]−
˚A
Parameter K2-30 K2-34 1s−10−15
2−
Planetproperties m
K(m/s) 79.9±4.0 209±12 ergsc10−16
[
Rp/R(cid:63) 0.1302±0.0026 0.0905±0.0017 Flux10−17
M (M ) 0.623±0.031 1.76±0.13
p Jup
Rp(RJup) 1.196±0.060 1.350±0.067 O-Cmag] 00..01
ρp(ρJup) 0.364±0.058 0.71±0.11 [−0.1 104 105
T (K) 1185+44 1742±38 Wavelength[A˚]
eq −28
Orbitalproperties
Period(days) 4.098507±0.000028 2.995607±0.000017 10−13
T0(MBJDa,days) 63.80710±0.00027 141.35132±0.00022 1˚A]−10−14
i(deg) 86.32±0.38 82.06±0.51 1−
s
e 0.027+0.036 0.0(assumed) 2m−10−15
−0.020 c
ω(deg) 120+100 - gs
a(au) 0.04986±−501.00035 0.04419+0.00063 x[er10−16
−0.00110 Flu
a/R(cid:63) 11.40±0.52 6.20±0.25 10−17
Tdur(bhporiumrasry) 20..732515±±00..003360 02..845972±±00..002233 O-C[mag]−000...101 104 105
Hostproperties Wavelength[A˚]
M(cid:63)(M(cid:12)) 0.984±0.020 1.281+−00..005951 Fig.4.ResultsoftheSEDfittinginthejointanalysisofthedatawith
R (R ) 0.941±0.041 1.526±0.076 PASTIS for K2-30 (top panel) and K2-34 (bottom panel). The final
(cid:63) (cid:12)
ρ (ρ ) 1.18±0.15 0.356±0.044 modelsareshownwithsolidlinesandtheresidualsofthedataarepre-
(cid:63) (cid:12)
sentedinthelowerpartofeachpanel.
V (km/s) 35.5090±0.0087 46.311±0.013
sys
d(pc) 323±14 377±20
E(B-V) 0.253±0.014 0.036±0.020
logg(cgs) 4.484±0.042 4.173±0.032
Teff 5581±38 6132±47
[Fe/H](dex) 0.136±0.029 0.24±0.22
logL/L (dex) -0.112±0.039 0.471±0.048
(cid:12)
ua 0.24±0.18 0.18+0.20
−0.13
ub 0.34±0.28 0.28±0.28
vsini(km/s) 3.9±1.1 5.2±1.4
Jitters(σ)andinstrumentaloffsets(∆RV)
σ (m/s) 3.6+4.8 16+29
RV,HARPS−N −2.5 11
σ (m/s) 10.3+13.0 13.2+22.0
RV,SOPHIE −7.2 −9.5
σ (m/s) - 43±21
RV,CAFE
∆RV (m/s) -121.5±9.1 -81±26
S,H−N
∆RV (m/s) - 228±50
S,CAFE
σ (ppm) 385±18 188.3±7.3
K2
σ (mag) 0.016+0.016 0.065+0.032
SED −0.011 −0.021
K2contamination 0.032+0.036 0.025+0.031
−0.023 −0.018
Notes.(a)ModifiedBarycentricJulianDate=BJD-2457000(days)
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