J/A+A/612/A41 HD 176986 HARPS + HARPS-N data (Suarez Mascareno+, 2018)
The RoPES project with HARPS and HARPS-N.
I. A system of super-Earths orbiting the moderately active K-dwarf HD 176986.
Suarez Mascareno A., Gonzalez Hernandez J.I., Rebolo R., Velasco S.,
Toledo-Padron B., Udry S., Motalebi F., Segransan D., Wyttenbach A.,
Mayor M., Pepe F., Lovis C., Santos N. C., Figueira P., Esposito M.
<Astron. Astrophys. 612, A41 (2018)>
=2018A&A...612A..41S 2018A&A...612A..41S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, double and multiple ; Planets ; Exoplanets;
Radial velocities
Keywords: planetary systems - techniques: radial velocities -
planets and satellites: detection - stars: rotation -
stars: individual: HD 176986 -
planets and satellites: terrestrial planets
Abstract:
We report the discovery of a system of two super-Earths orbiting the
moderately active K-dwarf HD 176986. This work is part of the RoPES RV
program of G- and K-type stars that combines radial velocity from both
HARPS and HARPS-N spectrograph to search for short-period terrestrial
planets. HD 176986 b and c are super-Earth mass planets with masses of
5.74 and 9.18 Me, with orbital periods of 6.49 and 16.82 days, at a
distances of 0.063 and 0.119AU, in orbits that are consistent with
circular. The host star is a K2.5 dwarf, and in spite of its modest
level of chromospheric activity log(R'hk)=-4.90±0.04, shows a
complex activity pattern. Along with the discovery of the planets we
study the magnetic cycle and rotation of the star. HD 176986 proves to
be suitable to test the available techniques of RV analysis and our
understanding of stellar activity.
Description:
HD 176986 has been extensively monitored since mid-2004 with HARPS and
HARPS-N. The star was followed first in the HARPS planet-search
programme on Guaranteed Time Observations (GTO, PI: M. Mayor) on-going
for 6 years between autumn 2003 and spring 2009. The observations were
then continued within the ESO Large Programs 183.C-0972+183.C-1005
(PI: S. Udry). Then it was observed with HARPS-N from 2014 onwards as
part of the RoPES project using a nightly-cadence observation strategy
aimed at the detection of very low-mass planets in close orbits of
quiet G and K-type stars. HARPS Mayor2003 and HARPS-N Cosentino2012
are two fibre-fed high resolution echelle spectrographs installed at
the 3.6m ESO telescope in La Silla Observatory (Chile) and at the
Telescopio Nazionale Galileo in the Roque de los Muchachos Observatory
(Spain), respectively. During the HARPS campaigns our star was
typically observed once per night using an exposure time of 900s,
with just a few exceptions. In the HARPS-N campaign the star was
always observed using 3x300s exposures per visit, having one visit
per night during the first years and two visits separated by a few
hours during the 2016 and 2017 campaigns. The data is then re-sampled
and averaged into 1 hour bins. The combination of both observational
programmes provided 156 HARPS observations and 103 HARPS-N newly
acquired observations, coming from 234 individual nights, during 13.2
years of observations.
Objects:
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RA (2000) DE Designation(s)
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19 03 05.87 -11 02 38.1 HD 176986 = HIP 93540
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 259 HARPS+HARPS-N data
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 d BJD Julian date (BJD-2450000)
10- 17 F8.2 m/s RV Radial velocity
19- 22 F4.2 m/s e_RV Radial velocity uncertainty
24- 29 F6.1 m/s FWHM FWHM of the CCF
31- 33 F3.1 m/s e_FWHM FWHM uncertainty
35- 38 F4.1 m/s Span Bisector span velocity
40- 42 F3.1 m/s e_Span Bisector span velocity
44- 49 F6.4 [-] SMW Mount Wilson S index
51- 56 F6.4 [-] e_SMW Mount Wilson S index uncertainty
58- 64 F7.5 [-] Ha Halpha index
66- 72 F7.5 [-] e_Ha Halpha index uncertainty
74 A1 [-] Spec [012] Spectrograph (1)
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Note (1): Spectrograph as follows:
0 = HARPS
1 = HARPS post-upgrade
2 = HARPS-N
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Acknowledgements:
Alejandro Suarez Mascareno, asuarezmascareno(at)unige.ch
(End) Patricia Vannier [CDS] 01-Dec-2017