J/A+A/633/A44 HARPS Young Nearby Stars - YNS (Grandjean+, 2020)
A HARPS RV search for planets around young nearby stars.
Grandjean A., Larange A.-M., Kepler M., Meunier N., Mignon L., Borgniet S.,
Chauvin G., Desidera S., Galland F., Messina S., Sterzik M., Pantoja B.,
Rodet L., Zicher N.
<Astron. Astrophys. 633, A44 (2020)>
=2020A&A...633A..44G 2020A&A...633A..44G (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Stars, early-type ; Stars, late-type ; Radial velocities
Keywords: techniques: radial velocities - stars: activity -
binaries: spectroscopic - planetary systems - starspots -
stars: variables: general
Abstract:
Young nearby stars are good candidates in the search for planets with
both radial velocity (RV) and direct imaging techniques. This, in
turn, allows for the computation of the giant planet occurrence rates
at all separations. The RV search around young stars is a challenge as
they are generally faster rotators than older stars of similar
spectral types and they exhibit signatures of magnetic activity
(spots) or pulsation in their RV time series. Specific analyses are
necessary to characterize, and possibly correct for, this activity.
Our aim is to search for planets around young nearby stars and to
estimate the giant planet (GP) occurrence rates for periods up to 1000
days.
We used the HARPS spectrograph on the 3.6m telescope at La Silla
Observatory to observe 89 A-M young (<600Myr) stars. We used our
SAFIR (Spectroscopic data via Analysis of the Fourier Interspectrum
Radial velocities) software to compute the RV and other spectroscopic
observables. Then, we computed the companion occurrence rates on this
sample.
We confirm the binary nature of HD 177171, HD 181321 and HD 186704. We
report the detection of a close low mass stellar companion for HIP
36985. No planetary companion was detected. We obtain upper limits on
the GP (<13MJup) and BD (∈[13;80]MJup) occurrence rates based
on 83 young stars for periods less than 1000 days, which are set,
2-2+3 and 1-1+3%.
Description:
The HARPS Young Nearby Stars catalogue (YNS) is based on a survey of
ESO HARPS on young stars and contains 89 A to M type stars. The
catalog presents Radial velocity (RV) and activity indicator results.
The 89 stars were observed mainly between 2013 and 2016. Some stars
were part of previous surveys by Borgniet et al. (2019A&A...621A..87B 2019A&A...621A..87B)
and Lagrange et al. (2009A&A...495..335L 2009A&A...495..335L), which allowed to reach a
time base- line up to 10yr. Some stars had already been observed with
HARPS before, some since the HARPS commissioning in 2003. Additional
observations were also obtained in October 2017, December 2017, and
March 2018. The observing strategy is the one described in Borgniet et
al. (2017A&A...599A..57B 2017A&A...599A..57B), which consist of recording two spectra per
visit and to observe each target on several consecutive nights to have
a good sampling of the short-term jitter. The median time baseline is
1639 days (mean time baseline of 2324 days), with a median number of
spectra per target of 25 (52 on average) spaced on a median number of
12 nights (17 on average). Details can be found in Table A.1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 38 89 List of targets and positions
tablea1.dat 176 89 Stellar characteristics of the survey
tablea2.dat 99 89 Results of the survey
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Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Name
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 24 F7.4 s RAs Right ascension (J2000)
26 A1 --- DE- Declination sign (J2000)
27- 28 I2 deg DEd Declination (J2000)
30- 31 I2 arcmin DEm Declination (J2000)
33- 38 F6.3 arcsec DEs Declination (J2000)
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Name
12- 17 I6 --- HIP ? Hipparcos number
19- 23 A5 --- SpType Spectral type
25- 30 F6.3 mag B-V B-V colour index
32- 36 F5.3 Msun Mass ? Stellar mass found in literature
38- 56 A19 --- r_Mass Bibcode of mass reference
58- 61 I4 Myr Age ? Age found in literature
63- 66 I4 Myr e_Age ? Age negative error
68- 71 I4 Myr E_Age ? Age positive error
73- 91 A19 --- r_Age Bibcode of age reference
93- 97 F5.1 km/s vsini Rotational velocity
99-105 F7.4 d Prot ? Rotation period found in literature
107-112 F6.4 d e_Prot ? Rotation period uncertainty
114-132 A19 --- r_Prot Bibcode of rotation period reference
134 A1 --- IR IR excess flag (1)
136-154 A19 --- r_IR Bibcode of IR excess reference
156 A1 --- D Imaged disc flag (2)
158-176 A19 --- r_D Bibcode of disc reference
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Note (1): IR excess flags as follows:
y = Report of an IR excess
n = Report of an absence of IR excess
- = No report found about IR excess
Note (2): Disc flags as follows:
y = Report of disc in imagery
n = Report of absence of disc in imagery
- = No report found about disc
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Name
12- 17 I6 --- HIP ? Hipparcos number
19- 23 A5 --- SpType Spectral type
25- 28 I4 d TBL Time baseline
30- 33 I4 --- Nsp Total number of computed spectra
35- 41 F7.1 m/s RVAmp Radial velocity amplitude
43- 48 F6.1 m/s RVrms Radial velocity rms
50- 55 F6.1 m/s e_RV Radial velocity mean uncertainty
57- 64 F8.1 m/s BVS ? Bisector velocity span
66- 70 F5.1 m/s BVSrms ? Bisector velocity span rms
72- 78 F7.1 m/s e_BVS ? Bisector velocity span mean uncertainty
80- 84 F5.2 --- RV-BVScorr ? RV-BVS correlation factor
86- 90 F5.1 km/s ? FWHM mean uncertainty
92- 97 F6.3 --- <logR'HK> ? logR'HK mean uncertainty
99 A1 --- V Dominant source of RV (1)
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Note (1): Dominant source of RV variations flag as follows:
A = Stellar activity (spots)
P = Pulsations
B = Binary companion
T = Long period companion (Trend)
- = Not determined
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Acknowledgements:
Antoine Grandjean, antoine.grandjean1(at)univ-grenoble-alpes.fr
(End) A. Grandjean [Univ. Grenoble-Alpes], P. Vannier [CDS] 24-Oct-2019