J/A+A/620/A139 Planet candidates in open clusters (Leao+, 2018)
Incidence of planet candidates in open clusters and a planet confirmation.
Leao I.C., Canto Martins B.L., Alves S., Pereira De Oliveira G., Cortes C.,
Brucalassi A., Melo C.H.F., De Freitas D.B., Pasquini L., de Medeiros J.R.
<Astron. Astrophys., 620, A139 (2018)>
=2018A&A...620A.139L 2018A&A...620A.139L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, late-type ; Radial velocities
Keywords: planetary systems - open clusters and associations: general -
stars: late-type - binaries: spectroscopic -
techniques: radial velocities
Abstract:
Detecting exoplanets in clusters of different ages is a powerful tool
for understanding a number of open questions, such as how the
occurrence rate of planets depends on stellar metallicity, on mass, or
on stellar environment.
We present the first results of our HARPS long-term radial velocity
(RV) survey which aims to discover exoplanets around intermediate-mass
(between ∼2 and 6M☉) evolved stars in open clusters.
We selected 826 bona fide HARPS observations of 114 giants from an
initial list of 29 open clusters and computed the half-peak to peak
variability of the HARPS RV measurements, namely ΔRV/2, for each
target, to search for the best planet-host candidates. We also
performed time series analyses for a few targets for which we have
enough observations to search for orbital solutions.
Although we attempted to rule out the presence of binaries on the
basis of previous surveys, we detected 14 new binary candidates in our
sample, most of them identified from a comparison between HARPS and
CORAVEL data. We also suggest 11 new planet-host candidates based on a
relation between the stellar surface gravity and ΔRV/2. Ten of
the candidates are less than 3M☉, showing evidence of a low
planet occurrence rate for massive stars. One of the planet-host
candidates and one of the binary candidates show very clear RV
periodic variations, allowing us to confirm the discovery of a new
planet and to compute the orbital solution for the binary. The planet
is IC 4651 9122b, with a minimum mass of msini=6.3MJ and a semimajor
axis a=2.0AU. The binary companion is NGC 5822 201B, with a very low
minimum mass of msini=0.11M☉ and a semimajor axis a=6.5AU, which
is comparable to the Jupiter distance to the Sun.
Description:
Supplementary data for the paper of Leao et al. (2018A&A...620A.139L 2018A&A...620A.139L).
Table A.1 is provided with cross-match identification and ICRS J2000
coordinates. An additional table gives the HARPS reduced radial
velocity and activity proxy measurements used in the time-series
analyses. The table contains all the 994 HARPS measurements of 152
stars belonging to 29 open clusters initially considered in the paper
that provided the final sample of 826 effective observations of 114
stars (see paper for details).
Based on observations collected with the 3.6m Telescope (La Silla
Observatory, ESO, Chile) using the HARPS instrument (programs ID:
091.C-0438, 092.C-0282, and 094.C-0297).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 134 114 Analysis of Delta RV/2 for the final sample
rv.dat 157 994 Radial velocity and activity proxy data
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See also:
J/A+A/485/303 : RVs for 1309 stars and 166 OCl (Mermilliod+, 2008)
J/A+A/438/1163 : Catalogue of Open Cluster Data (Kharchenko+, 2005)
J/MNRAS/399/2146 : Orbits of open clusters in the Galaxy (Wu+, 2009)
J/A+A/561/A93 : On the metallicity of open clusters. II. (Heiter+, 2014)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Designation in the paper
16- 38 A23 --- SName SIMBAD recognizable name
41- 42 I2 h RAh Right ascension (J2000)
44- 45 I2 min RAm Right ascension (J2000)
47- 53 F7.4 s RAs Right ascension (J2000)
55 A1 --- DE- Declination sign (J2000)
56- 57 I2 deg DEd Declination (J2000)
59- 60 I2 arcmin DEm Declination (J2000)
62- 68 F7.4 arcsec DEs Declination (J2000)
69- 76 F8.3 mag Vmag ?=-1 Visual magnitude from SIMBAD
77- 83 F7.2 [cm/s2] logg Logarithm of stellar surface gravity
84- 86 A3 --- f_logg ? Flag on logg (2)
87- 94 F8.2 km/s RVM08 CORAVEL RV measurement from M08 (3)
95- 98 I4 --- Neff Effective number of HARPS
observations (4)
99-104 I6 d tspan Time span of HARPS observations
105-113 F9.3 km/s RVH RV average of HARPS observations
114-121 F8.2 m/s DRV2H half peak-to-peak RV, DeltaRV/2
122-128 I7 m/s DRVH-C Difference between HARPS and CORAVEL RVs (5)
129-134 A6 --- Flag ? Candidate flag (6)
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Note (2): Flag (d) for photometric logg estimation
Note (3): Taken from Mermillod et al. (2008, Cat. J/A+A/485/303).
Note (4): Neff refers to the effective number of observations after averaging
those collected within less than 3 days of time interval
(see paper for details).
Note (5): DRVH-C = RVH - RVM08 - Offset, where Offset is provided in Table 2
of the paper.
Note (6): Flags are as follows:
p = planet-host candidate, where "(A)", "(B)", etc. are analyzed in more
details in the paper.
B = long-period binary
[B] = short-period binary
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Byte-by-byte Description of file: rv.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Designation in the paper
16- 33 F18.8 h BJD Baricentric Julian day
34- 44 F11.5 km/s RV Radial velocity
45- 51 F7.2 m/s e_RV Standard error on radial velocity
52- 58 F7.2 km/s FWHM FWHM of the CCF
59- 65 F7.1 --- SNR400 Signal-to-noise ratio at 400 nm
66- 72 F7.1 --- SNR490 Signal-to-noise ratio at 490 nm
73- 81 F9.1 m/s Bis ?=-9999.0 Bisector time span (1)
82- 88 F7.1 m/s e_Bis Uncertainty on bisector time span
89- 97 F9.5 --- Sindex ?=-1 Uncalibrated S index (2)
98-106 F9.5 --- e_Sindex ?=-1 Uncertainty on Sindex (2)
109-111 A3 --- qflag Quality flag (3)
112-126 A15 --- ProgID ESO Program ID
127-157 A31 --- ObsName ESO Observation name
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Note (1): Null = -9999.0 (invalid value)
Note (2): Null = -1 (no S index determination)
Note (3): Flag (x) = bad quality data
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Acknowledgements:
Izan de Castro Leao, izan(at)fisica.ufrn.br,
Universidade Federal do Rio Grande do Norte
(End) Izan de Castro Leao [Brazil], Patricia Vannier [CDS] 11-Mar-2019