J/ApJS/246/11 Search for nearby earth analogs. II. RV analysis. (Feng+, 2020)
Search for nearby earth analogs.
II. Detection of five new planets, eight planet candidates, and confirmation of
three planets around nine nearby M dwarfs.
Feng F., Butler R.P., Shectman S.A., Crane J.D., Vogt S., Chambers J.,
Jones H.R.A., Wang S.X., Teske J.K., Burt J., Diaz M.R., Thompson I.B.
<Astrophys. J. Suppl. Ser., 246, 11 (2020)>
=2020ApJS..246...11F 2020ApJS..246...11F
ADC_Keywords: Radial velocities; Spectroscopy; Stars, M-type
Keywords: Exoplanet astronomy ; Radial velocity ; Exoplanet detection methods ;
M dwarf stars ; Astrostatistics ; High resolution spectroscopy
Abstract:
Zechmeister et al. (2009, J/A+A/505/859) surveyed 38 nearby M dwarfs
from 2000 to 2007 March with VLT2 and the Ultraviolet and Visual
Echelle Spectrograph (UVES) spectrometer. These data have recently
been reanalyzed, yielding a significant improvement in the Doppler
velocity precision. Spurred by this, we have combined the UVES data
with velocity sets from High Accuracy Radial velocity Planet Searcher,
Magellan/Planet Finder Spectrograph, and Keck/High Resolution Echelle
Spectrometer. Sixteen planet candidates have been uncovered orbiting
nine M dwarfs. Five of them are new planets corresponding to radial
velocity signals, which are not sensitive to the choice of noise
models and are identified in multiple data sets over various time
spans. Eight candidate planets require additional observation to be
confirmed. We also confirm three previously reported planets. Among
the new planets, GJ 180 d and GJ 229A c are super-Earths located in
the conservative habitable zones of their host stars. We investigate
their dynamical stability using the Monte Carlo approach and find both
planetary orbits are robust to the gravitational perturbations of the
companion planets. Due to their proximity to the Sun, the angular
separation between the host stars and the potentially habitable
planets in these two systems is 25 and 59 mas, respectively. They are
thus good candidates for future direct imaging by James Webb Space
Telescope and E-ELT. In addition, we find GJ 433 c, a cold
super-Neptune belonging to an unexplored population of Neptune-like
planets. With a separation of 0.5" from its host star, GJ 433 c is
probably the first realistic candidate for the direct imaging of cold
Neptunes. A comprehensive survey of these planets is important for the
studies of planet formation.
Description:
All of the stars in Table 1 were observed with the Ultraviolet and
Visual Echelle Spectrograph (UVES) on the VLT-UT2 telescope between
2000 and 2007 March (see Zechmeister+ 2009, J/A+A/505/859). The
velocities reported here are the "unbinned" velocities published in
Butler+, 2019, J/AJ/158/251
We have obtained all the publicly reduced High Accuracy Radial
velocity Planet Searcher (HARPS) spectra from the ESO archive.
The Carnegie Planet Finder Spectrograph (PFS) is a purpose-built
iodine precision velocity echelle that is used on the 6.5m Magellan II
(Clay) telescope.
The Keck HIRES program is the longest continuously running precision
velocity survey, having commenced in 1996. HIRES is permanently
mounted on the Nasmyth platform on the Keck I 10m telescope. The data
for this program are from the analysis of Butler+ (2017, J/AJ/153/208).
We have reduced all the data, starting with the raw images.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 12 Stellar parameters and radial velocity (RV)
data sets for stars
fig1.dat 42 2281 Doppler velocity data sets of VLT/UVES, Keck/HIRES,
ESO/HARPS and Magellan/PFS for the 12 stars
reported here (Data behind Figure 1)
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See also:
J/ApJ/634/625 : Radial velocities and photometry of GJ 876 (Rivera+, 2005)
J/ApJ/646/505 : Catalog of nearby exoplanets (Butler+, 2006)
J/A+A/505/859 : M dwarfs radial velocities (Zechmeister+, 2009)
J/ApJ/723/954 : HIRES radial velocities of GJ 581 (Vogt+, 2010)
J/A+A/534/A58 : HD20794, HD85512, HD192310 HARPS RVs (Pepe+, 2011)
J/ApJS/200/15 : HARPS-TERRA project. I. (Anglada-Escude+, 2012)
J/A+A/551/A79 : RV periodic variations in τ Ceti (Tuomi+, 2013)
J/A+A/602/A88 : 5 M dwarfs radial velocity curves (Astudillo-Defru+, 2017)
J/AJ/153/208 : LCES HIRES/Keck RV Exoplanet Survey (Butler+, 2017)
J/A+A/605/A72 : Planetary systems AMD-stability (Laskar+, 2017)
J/other/Nat/563.365 : Barnard's star radial velocity curve (Ribas+, 2018)
J/AJ/158/251 : New reduction of UVES data for 35 M dwarfs (Butler+, 2019)
J/A+A/625/A68 : Radii and masses of the CARMENES targets (Schweitzer+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Main name of the star
9- 18 A10 --- OName Other name(s) (1)
20- 25 A6 --- SpT MK spectral type (1)
27- 31 F5.2 mag Vmag [8.14/12.5] V magnitude (1)
33- 36 F4.2 Msun Mass [0.27/0.69] Mass (1)
38- 40 I3 --- Nuves [5/167] Number of UVES RV points
42- 43 I2 --- Nkeck [0/64] Number of Keck RV points
45- 47 I3 --- NHarps1 [3/124] Number of HARPSpre RV points
49- 50 I2 --- NHarps2 [0/76] Number of HARPSpost RV points
52- 53 I2 --- Npsf1 [0/49] Number of PSFpre RV points
55 I1 --- Npsf2 [0/4] Number of PSFpost RV points
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Note (1): The spectral type, stellar mass, and V magnitudes are from Table 2
of Zechmeister+, 2009, J/A+A/505/859 and also Table 1 of
Butler+, 2019, J/AJ/158/251
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Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Star name
9- 19 F11.6 d JD Truncated Julian date; JD-2450000
21- 26 F6.2 m/s RVrel [-39.1/37.4] Radial velocity
28- 32 F5.2 m/s e_RVrel [0.3/13.1] Uncertainty in RVrel
34- 42 A9 --- Inst Instrument name
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Nov-2020