J/AJ/154/226 Photometry and radial velocities of K2-131 (Dai+, 2017)
The discovery and mass measurement of a new ultra-short-period planet: K2-131b.
Dai F., Winn J.N., Gandolfi D., Wang S.X., Teske J.K., Burt J., Albrecht S.,
Barragan O., Cochran W.D., Endl M., Fridlund M., Hatzes A.P., Hirano T.,
Hirsch L.A., Johnson M.C., Bo Justesen A., Livingston J., Persson C.M.,
Prieto-Arranz J., Vanderburg A., Alonso R., Antoniciello G., Arriagada P.,
Butler R.P., Cabrera J., Crane J.D., Cusano F., Csizmadia S., Deeg H.,
Dieterich S.B., Eigmuller P., Erikson A., Everett M.E., Fukui A., Grziwa S.,
Guenther E.W., Henry G.W., Howell S.B., Johnson J.A., Korth J., Kuzuhara M.,
Narita N., Nespral D., Nowak G., Palle E., Patzold M., Rauer H.,
Rodriguez P.M., Shectman S.A., Smith A.M.S., Thompson I.B., Van Eylen V.,
Williamson M.W., Wittenmyer R.A.
<Astron. J., 154, 226 (2017)>
=2017AJ....154..226D 2017AJ....154..226D (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets ; Stars, dwarfs ; Photometry, CCD ; Radial velocities
Keywords: planetary systems - stars: individual (EPIC 228732031)
Abstract:
We report the discovery of a new ultra-short-period planet and summarize
the properties of all such planets for which the mass and radius have
been measured. The new planet, K2-131b, was discovered in K2 Campaign 10.
It has a radius of 1.81-0.12+0.16 R⊕ and orbits a G dwarf with
a period of 8.9 hr. Radial velocities obtained with Magellan/PFS and
TNG/HARPS-N show evidence for stellar activity along with orbital motion.
We determined the planetary mass using two different methods: (1) the
"floating chunk offset" method, based only on changes in velocity observed
on the same night; and (2) a Gaussian process regression based on both
the radial velocity and photometric time series. The results are
consistent and lead to a mass measurement of 6.5±1.6 M⊕ and
a mean density of 6.0-2.7+3.0 g/cm3.
Description:
We observed EPIC 228732031 nightly with the Tennessee State University
Celestron 14 inch (C14) Automated Imaging Telescope (AIT) located at
Fairborn Observatory, Arizona (see, e.g., Henry 1999PASP..111..845H 1999PASP..111..845H).
The observations were made in the Cousins R bandpass.
EPIC 228732031 was monitored for photometric variability in the Bessel
V band from 2017 March 21 to April 1 using the Henrietta Swope 1 m
telescope at Las Campanas Observatory.
Between 2017 January 29 and April 1 (UT), we collected 41 spectra of
EPIC 228732031 using the HARPS-N spectrograph (R∼115000; Cosentino et al.
2012SPIE.8446E..1VC) mounted on the 3.58 m Telescopio Nazionale Galileo
(TNG) of Roque de los Muchachos Observatory, in La Palma.
We also observed EPIC 228732031 between 2017 March 16 and April 5 (UT),
with the Carnegie Planet Finder Spectrograph (PFS; R∼76,000, Crane et al.
2010SPIE.7735E..53C 2010SPIE.7735E..53C) on the 6.5 m Magellan/Clay Telescope at Las Campanas
Observatory, Chile.
Objects:
------------------------------------------------------
RA (ICRS) DE Designation(s)
------------------------------------------------------
12 11 00.38 -09 45 54.8 K2-131b = K2-131b
12 11 00.38 -09 45 54.8 EPIC 228732031 = K2-131
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 30 149 AIT Photometry
table2.dat 27 10 Swope Photometry
table3.dat 62 41 HARPS-N Observations
table4.dat 33 32 PFS Observations
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See also:
J/ApJ/787/47 : 106 Kepler ultra-short-period planets (Sanchis-Ojeda+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Barycentric Julian Date; TDB
15- 22 F8.5 mag DRmag [-0.95431/-0.92411] Differential Cousins R band
magnitude
24- 30 F7.5 mag e_DRmag [0.00022/0.00752] Uncertainty in DRmag
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Barycentric Julian Date; TDB
15- 20 F6.4 --- RVFlux [0.9917/1.0042] Bessel V band relative flux
22- 27 F6.4 --- e_RVFlux [0.0021/0.0046] Uncertainty in RVFlux
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Barycentric Julian Date; TDB
14 A1 --- n_BJD [a] Note on BJD (G1)
16- 23 F8.2 m/s RV [-6892.8/-6657.92] Radial velocity
25- 30 F6.2 m/s e_RV [3.27/106.24] Uncertainty in RV
32- 36 F5.3 m/s FWHM [7.765/7.967] Full width at half maximum
38- 44 F7.4 m/s BIS [-0.0087/0.3354] Bisector span of the
cross-correlation function
46- 51 F6.3 [-] logRHK [-4.566/-4.139] The Ca II H & K chromospheric
activity index (log R'HK)
53- 57 F5.3 [-] e_logRHK [0.01/0.538] Uncertainty in logRHK
59- 62 F4.1 --- S/N [1.5/40.7] Signal-to-noise ratio per pixel
at 5500Å
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Barycentric Julian Date; TDB
14 A1 --- n_BJD [a] Note on BJD (G1)
16- 21 F6.2 m/s RV [-51.72/29.22] Radial velocity
23- 27 F5.2 m/s e_RV [3.26/10.95] Uncertainty in RV
29- 33 F5.3 --- SHK [0.437/0.885] The Ca II H & K chromospheric
activity indicator SHK
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Global note:
Note (G1): Note as follows:
a = Excluded from analysis due to bad seeing.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 16-Aug-2018