J/A+A/642/A31 pi Men radial velocity curves (Damasso+, 2020)
A precise architecture characterization of the pi Mensae planetary system.
Damasso M., Sozzetti A., Lovis C., Barros S.C.C., Sousa S.G.,
Demangeon O.D.S., Faria J.P., Lillo-Box J., Cristiani S., Pepe F.,
Rebolo R., Santos N.C., Zapatero Osorio M.R., Gonzalez Hernandez J.I.,
Amate M., Pasquini L., Zerbi F.M., Adibekyan V., Abreu M., Aolter M.,
Alibert Y., Aliverti M., Allart R., Allende Prieto C., Alvarez D., Alves D.,
Avila G., Baldini V., Bandy T., Benz W., Bianco A., Borsa F., Bossini D.,
Bourrier V., Bouchy F., Broeg C., Cabral A., Calderone G., Cirami R.,
Coelho J., Conconi P., Coretti I., Cumani C., Cupani G., D'Odorico V.,
Deiries S., Dekker H., Delabre B., Di Marcantonio P., Dumusque X.,
Ehrenreich D., Figueira P., Fragoso A., Genolet L., Genoni M.,
Genova Santos R., Hughes I., Iwert O., F.Kerber, Knudstrup J., Landoni M.,
Lavie B., Lizon J.-L., Lo Curto G., Maire C., J .A.P.Martins C.,
Megevand D., Mehner A., Micela G., Modigliani A., Molaro P., Monteiro M.A.,
Monteiro M.J.P.F.G., Moschetti M., Mueller E., Murphy M.T., Nunes N.,
Oggioni L., Oliveira A., Oshagh M., Palle E., Pariani G., Poretti E.,
Rasilla J.L., Rebordao J., Redaelli E.M., Riva M., Santana Tschudi S.,
Santin P., Santos P., Segransan D., Schmidt T.M., Segovia A., Sosnowska D.,
Spano P., Suarez Mascareno A., Tabernero H., Tenegi F., Udry S., Zanutta A.
<Astron. Astrophys. 642, A31 (2020)>
=2020A&A...642A..31D 2020A&A...642A..31D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple; Exoplanets; Radial velocities
Keywords: techniques: radial velocities; photometric - astrometry -
planetary systems - stars: individual: pi Men
Abstract:
The bright star π Men was chosen as the first target for a radial
velocity follow-up to test the performance of ESPRESSO, the new
high-resolution spectrograph at the ESO's Very-Large Telescope (VLT).
The star hosts a multi-planet system (a transiting 4M{earth} planet
at ∼0.07au, and a sub-stellar companion on a ∼2100-day eccentric
orbit) which is particularly appealing for a precise multi-technique
characterization. With the new ESPRESSO observations, that cover a
time span of 200days, we aim to improve the precision and accuracy of
the planet parameters and search for additional low-mass companions.
We also take advantage of new photometric transits of π Men c
observed by TESS over a time span that overlaps with that of the
ESPRESSO follow-up campaign. We analyse the enlarged spectroscopic and
photometric datasets and compare the results to those in the
literature. We further characterize the system by means of absolute
astrometry with Hipparcos and Gaia. We used the high-resolution
spectra of ESPRESSO for an independent determination of the stellar
fundamental parameters. We present a precise characterization of the
planetary system around π Men. The ESPRESSO radial velocities alone
(37 nightly binned data with typical uncertainty of 10cm/s) allow for
a precise retrieval of the Doppler signal induced by π Men c. The
residuals show an RMS of 1.2m/s, which is half that of the HARPS data
and, based on them, we put limits on the presence of additional
low-mass planets (e.g. we can exclude companions with a minimum mass
less than ∼2M{earth} within the orbit of π Men c). We improve the
ephemeris of π Men c using 18 additional TESS transits, and in
combination with the astrometric measurements, we determine the
inclination of the orbital plane of π Men b with high precision
(ib=45.8+1.4-1.1deg). This leads to the precise measurement of
its absolute mass mb=14.1+0.5-0.4Mjup, indicating that π Men
b can be classified as a brown dwarf. π Men represents a nice
example of the extreme precision radial velocities that can be
obtained with ESPRESSO for bright targets. Our determination of the
3-D architecture of the π Men planetary system, and the high
relative misalignment of the planetary orbital planes, put constraints
and challenges to the theories of formation and dynamical evolution of
planetary systems. The accurate measurement of the mass of π Men b
contributes to make the brown dwarf desert a bit greener.
Description:
The observations of pi Men with ESPRESSO (using the instrument in
single Unit Telescope mode with a median resolving power R=138000 over
the 378.2 and 788.7nm wavelength range) were carried out within one of
the sub-programmes of the Guaranteed Time Observations (GTOs), aimed
at using the very precise RVs to characterize (i.e. measure masses and
bulk densities) transiting planets discovered by TESS and Kepler's
second light K2 mission (see Pepe et al. 2020 (A&A, submitted) for a
detailed discussion of the ESPRESSO on-sky performance). The pi Men
system was observed starting from September 2018, right before the end
of the commissioning phase of the instrument, up to March 2019. We
collected 275 spectra over 37 nights (multiple and consecutive
exposures per night) during a total time span of 201 days. The spectra
were acquired with a typical exposure time of 120s, providing a median
signal-to-noise ratio S/N=243 per extracted pixel at λ=500nm.
In this work we also use previously unreleased spectra from CORALIE to
extract additional RVs. The pi Men system was observed with CORALIE
from November 1998 to February 2020, during which time 60 spectra with
typical exposure times of 300-600s (S/N=82-124 at 550nm) were
collected.
Radial velocities extracted from ESPRESSO and CORALIE spectra, and
spectroscopic stellar activity diagnostics from ESPRESSO.
Objects:
---------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------
05 37 09.89 -80 28 08.8 pi Men = HR 2022
---------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 77 275 *Radial velocities and activity diagnostics
extracted from ESPRESSO spectra
tableb2.dat 39 53 Radial velocities from CORALIE spectra
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Note on tableb1.dat: The last record was discarded from the analysis due to
poor S/N.
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See also:
J/A+A/619/L10 : pi Men radial velocity curves (Gandolfi+, 2018)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 d Time Epoch of observation (BJD-2450000)
13- 20 F8.2 m/s RV Systemic radial velocity
22- 25 F4.2 m/s e_RV Radial velocity error
27- 33 F7.2 m/s FWHM CCF FWHM
35- 41 F7.4 m/s BIS CCF BIS
43- 50 F8.6 --- Sind Chromospheric S index
52- 59 F8.6 --- e_Sind Chromospheric S index error
61- 68 F8.6 --- Halpha Chromospheric H-alpha index
70- 77 F8.6 --- e_Halpha Chromospheric H-alpha index error
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 d Time Epoch of observation (BJD-2450000)
14- 21 F8.2 m/s RV Systemic radial velocity
24- 28 F5.2 m/s e_RV Radial velocity error
30- 39 A10 --- Dataset Dataset (CORALIE-98, CORALIE-07 or CORALIE-14)
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Acknowledgements:
Mario Damasso, mario.damasso(at)inaf.it
(End) Mario Damasso [INAF, Italy], Patricia Vannier [CDS] 15-Jul-2020