J/AJ/156/213 Properties of N2K stars & new gas giant companions (Ment+, 2018)
Radial velocities from the N2K project: six new cold gas giant planets orbiting
HD 55696, HD 98736, HD 148164, HD 203473, and HD 211810.
Ment K., Fischer D.A., Bakos G., Howard A.W., Isaacson H.
<Astron. J., 156, 213 (2018)>
=2018AJ....156..213M 2018AJ....156..213M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Exoplanets ; Radial velocities ; Photometry, UBV ;
Spectral types ; Effective temperatures ; Abundances, [Fe/H] ;
Stars, masses ; Stars, diameters ; Stars, ages ; Spectroscopy
Keywords: planets and satellites: detection - surveys -
techniques: radial velocities
Abstract:
The N2K planet search program was designed to exploit the
planet-metallicity correlation by searching for gas giant planets orbiting
metal-rich stars. Here, we present the radial velocity measurements for
378 N2K target stars that were observed with the HIRES spectrograph at
Keck Observatory between 2004 and 2017. With this data set, we announce
the discovery of six new gas giant exoplanets: a double-planet system
orbiting HD 148164 (Msini of 1.23 and 5.16 MJUP) and single planet
detections around HD 55696 (Msini=3.87 MJUP), HD 98736
(Msini=2.33 MJUP), HD 203473 (Msini=7.8 MJUP), and HD 211810
(Msini=0.67 MJUP). These gas giant companions have orbital semimajor
axes between 1.0 and 6.2 au and eccentricities ranging from 0.13 to 0.71.
We also report evidence for three gravitationally bound companions with
Msini between 20 and 30 MJUP, placing them in the mass range of brown
dwarfs, around HD 148284, HD 214823, and HD 217850, and four low-mass
stellar companions orbiting HD 3404, HD 24505, HD 98630, and HD 103459.
In addition, we present updated orbital parameters for 42 previously
announced planets. We also report a nondetection of the putative companion
HD 73256 b. Finally, we highlight the most promising candidates for direct
imaging and astrometric detection, and we find that many hot Jupiters
from our sample could be detectable by state-of-the-art telescopes
such as Gaia.
Description:
The "Next 2000" or N2K consortium (Fischer et al. 2005ApJ...620..481F 2005ApJ...620..481F)
was started in 2003 and exploited the planet-metallicity correlation with
the goal of detecting additional hot Jupiters for transit-search programs.
The data presented here were obtained at the 10 m Keck Observatory atop
Maunakea in Hawai'i, using the HIRES spectrograph. The spectra have a
fairly consistent signal-to-noise ratio (S/N) of about 200 since the
exposures are automatically terminated with an exposure meter that picks
off a small fraction of light behind the slit. The B5 decker was used,
providing a spectral resolution of about 50000. Typical exposure times
range from a few to 15 minutes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 137 378 Properties of N2K stars
table2.dat 59 5008 Radial velocities for N2K stars
table4.dat 165 62 Best fits for stellar companions
table11.dat 73 62 Interesting targets for direct imaging
table12.dat 76 62 Interesting targets for astrometric detection
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
V/136 : Teff and metallicities for Tycho-2 stars (Ammons+, 2006)
J/ApJ/637/1102 : Lick indices for metal-rich stars (Robinson+, 2006)
J/ApJS/169/430 : Atmospheric parameters of 1907 metal-rich stars
(Robinson+, 2007)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Star Star name
12- 16 F5.2 mag Vmag [7.45/12.84]? Apparent V magnitude from
the Hipparcos catalog (Cat. I/239)
18- 23 F6.3 mag B-V [-0.24/1.13]? B-V color from the Hipparcos
catalog (Cat. I/239)
25- 35 A11 --- SpType Spectral type
37- 40 I4 K Teff [0/6380]? Effective temperature
42- 46 F5.2 [-] [Fe/H] [-0.36/0.51]? Metallicity
48- 52 F5.2 Msun M* [0.49/1.95]? Stellar mass
54- 58 F5.2 Msun e_M* [0.02/0.81]? Uncertainty in M*
60- 64 F5.2 [Lsun] logL* [-0.68/3.6]? Log of stellar luminosity
66- 70 F5.2 [Lsun] e_logL* [0.02/3.6]? Uncertainty in logL*
72- 76 F5.2 Rsun R* [0.53/4.06]? Stellar radius
78- 82 F5.2 Rsun e_R* [0.01/1.85]? Uncertainty in R*
84- 88 F5.2 Gyr Age [0/14.8]? Age
90- 93 F4.2 Gyr e_Age [0/5.01]? Uncertainty in Age
95- 99 F5.3 --- SHK [0.104/0.527]? SHK activity index
101-105 F5.3 --- e_SHK [0/0.013]? Uncertainty in SHK
107-112 F6.3 [-] logRHK [-5.415/0]? Log of R'HK activity index
114-118 F5.3 [-] e_logRHK [0/0.035]? Uncertainty in logRHK
120-123 F4.2 m/s Jitter [2/7.01]? Stellar RV jitter estimate
125-127 I3 --- NRV [3/135] Number of RV measurements
129 I1 --- Nfit [0/3] Number of fitted companions
131-137 F7.2 m/s RMSres [0.65/9013.96] RMS of RV residuals, after
subtracting the fitted companions
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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- 10 A10 -- Star Star name
12- 21 F10.4 d JD [13014.716/17830.918] Julian Date (JD-2440000)
23- 40 F18.11 m/s RV [-20976.873/8217.7] Radial velocity
42- 52 F11.7 m/s e_RV [0.179945/312.842] Radial velocity error
54- 59 F6.4 -- SHK [0/0.535]? Ca II H&K line emission indicator
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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- 9 A9 --- Star Star name
11 A1 --- m_Star Multiplicity index on Star
13- 25 F13.7 d Per [2.1378431/13074] Orbital period
27- 27 A1 --- f_Per [f] Flag on Per (f=fixed value)
29- 39 F11.7 d e_Per [3.1e-06/982]? Uncertainty in Per
41- 47 F7.2 m/s K [6.22/3535] Radial velocity amplitude
49- 54 F6.2 m/s e_K [0.4/188] Uncertainty in K
56- 62 F7.5 --- e [0/0.8102] Eccentricity
64 A1 --- f_e [f] Flag on e (f=fixed value)
66- 72 F7.5 --- e_e [0.00087/0.14]? Uncertainty in e
74- 80 F7.3 deg omega [0.86/358] Longitude of periastron ω
82- 88 F7.3 deg e_omega [0.068/147] Uncertainty in omega
90-100 F11.5 d T0 [11450.84/16995] Time of periastron passage,
in Julian Date (JD-2450000)
102 A1 --- f_T0 [f] Flag on T0 (f=fixed value)
104-111 F8.4 d e_T0 [0.0024/542]? Uncertainty in T0
113-119 F7.3 Mjup Msini [0.055/359] Planet mass, times sin(i)
121-126 F6.3 Mjup e_Msini [0.01/30] Uncertainty in Msini
128-135 F8.5 AU a [0.0346/13.17] Semi-major axis
137-143 F7.5 AU e_a [0.00035/0.84] Uncertainty in a
145-151 F7.3 m/s/yr Trend [-47.2/7.83]? Trend in fit
153-157 F5.3 m/s/yr e_Trend [0.097/2]? Uncertainty in Trend
159 A1 --- f_Trend [abcd] Flag for model curvature (1)
161-165 F5.2 --- chi2 [0.37/21.73] Model reduced χ2 value
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Note (1): Model curvatures in fits as follows:
a = The model for HD 147506 includes a curvature term
of 6.11±0.26 m/s/yr2;
b = The model for HD 163607 includes a curvature term
of 0.96±0.18 m/s/yr2;
c = The model for HD 164509 includes a curvature term
of 0.58±0.11 m/s/yr2;
d = The model for HD 203473 includes a curvature term
of 3.91±0.30 m/s/yr2.
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star name
11 A1 --- m_Star Multiplicity index on Star
13- 18 F6.2 Mjup Msini [0.05/359.17] Planet mass, times sin(i)
20- 24 F5.2 Mjup e_Msini [0.01/29.64] Uncertainty in Msini
26- 30 F5.2 AU a [0.03/13.17] Semi-major axis
32- 35 F4.2 AU e_a [0/0.84] Uncertainty in a
37- 41 F5.3 --- e [0/0.81] Eccentricity
43- 47 F5.3 --- e_e [0/0.143] Uncertainty in e
49- 52 F4.1 Gyr Age [0/14.8]? Age
54- 56 F3.1 Gyr e_Age [0/3.9]? Uncertainty in Age
58- 62 F5.1 mas b_Sep [0.1/114.8] Lower range sky-projected angular
separation (1)
64- 68 F5.1 mas B_Sep [0.2/277.4] Upper range sky-projected angular
separation (1)
70- 73 F4.1 mas e_Sep [0/15.6] Uncertainty in separation (1)
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Note (1): Depending on the exact orbital configuration, the maximum
sky-projected separation falls within the range given here, with "b_Sep"
corresponding to an edge-on orbit with the apastron passage occurring right
behind the center of the star, and "B_Sep" representing a completely face-on
orbit. The exact time of the largest separation depends on the inclination
angle i, which cannot be determined from the RVs alone.
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Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star name
11 A1 --- m_Star Multiplicity index on Star
13- 18 F6.2 MJup Msini [0.05/359.17] Planet mass, times sin(i)
20- 24 F5.2 MJup e_Msini [0.01/29.64] Uncertainty in Msini
26- 32 F7.1 d Per [2.1/13074] Orbital period
34- 38 F5.1 d e_Per [0/982.1]? Uncertainty in Per
40- 44 F5.2 AU a [0.03/13.17] Semi-major axis
46- 49 F4.2 AU e_a [0/0.84] Uncertainty in a
51- 55 F5.3 --- e [0/0.81] Eccentricity
57- 61 F5.3 --- e_e [0/0.143] Uncertainty in e
63- 69 F7.1 uarcsec Sep [0/29437.8] Astrometric signature angle for
a circular orbit (1)
71- 76 F6.1 uarcsec e_Sep [0/6808.2] Uncertainty in Sep (1)
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Note (1): The detectability of orbits with e different from 0 depends on the
orbital angle.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 01-Apr-2019