J/A+A/702/A68 HIRES/Keck radial velocity database (Teklu+, 2025)
An updated catalog of HIRES/Keck radial velocity measurements.
Including Ca II H&K measurements.
Teklu J.T., Perdelwitz V., Butler R.P., Trifonov T., Vogt S.S., Mukhija D.,
Tal-Or L.
<Astron. Astrophys. 702, A68 (2025)>
=2025A&A...702A..68T 2025A&A...702A..68T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities
Keywords: techniques: radial velocities - stars: activity -
stars: chromospheres
Abstract:
The first HIRES/Keck precision radial velocity (RV) catalog was
released in 2017, followed by a second release in 2019, incorporating
corrections for minor but significant systematic errors. We have
expanded this catalog to March 2023, with 17971 RV measurements for
1702 stars. Furthermore, we have included the chromospheric emission
lines CaII H&K indicator (R'HK), which is among the most prominent
tracers of stellar activity. The manifestation of stellar activity,
accompanied by minor systematic errors in high-resolution optical
stellar spectra, could affect exoplanets detected by the RV method. We
provide R'HK measurements for∼40% of the HIRES catalog alongside RVs
to mitigate these effects. The precision RVs were obtained using an
iodine gas absorption cell, and relative, chromospheric emissions at
the CaII H&K lines were derived from the same spectra used for RV
measurements. The emitted flux was extracted by rectifying the
observed spectra with PHOENIX synthetic models across six narrow bands
surrounding the H and K lines, followed by the subtraction of the
photospheric contribution. The updated catalog may help distinguish
stellar activity effects from planetary signals in RV time series,
corroborating previously detected planetary candidates and aiding the
detection of new ones.
Description:
The updated HIRES catalog as of March 2023, which includes 17971
additional spectra for 1702 stars. This update also addresses minor
systematic errors in RVs and introduces two new stars: TOI 1173 and
TYC 1243-262-1. Additionally, it includes the chromospheric emission
lines CaII H&K indicator (R'HK) for 31218 spectra, representing 40%
of the total 78920 spectra. The availability of R'HK measurements was
constrained by data quality, with the highest-confidence
subset-referred to as the "good sample", comprising 1285 stars out of
the full catalog of 1702 stars. This subset represents the most
reliable data for analyzing stellar activity and its impact on RV
measurements.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 410 1702 Main stellar parameters of the HIRES sample and
statistical overview of the derived parameters
(tables 1 + 2)
tablea1.dat 448 78920 Individual radial velocities with NZP corrected
and uncorrected, chromospheric activity
indices, and all internal and custom flags
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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- 14 A14 --- Name Star name
16- 45 A30 --- Simbad Simbad identifier
47- 65 F19.15 deg RAdeg Right Ascension (J2000)
67- 83 F17.13 deg DEdeg Declination (J2000)
85- 92 F8.3 m/s RV ?=- Radial velocity (from catalog)
94-113 F20.17 m/s e_RV ?=- Radial velocity error (from catalog)
115-133 A19 --- r_RV Source of radial velocity
135-142 F8.3 K Teff ?=- Effective temperature
144-162 F19.15 K e_Teff ?=- Effective temperature error
164-167 A4 --- r_Teff Source of effective temperature error
169-174 F6.4 [cm/s2] logg ?=- Surface gravity
176-189 E14.12 [cm/s2] e_logg ?=- Surface gravity error
191-194 A4 --- r_logg Source of surface gravity
196-202 F7.4 [-] [M/H] ?=- Metallicity
204-212 F9.7 [-] e_[M/H] ?=- Metallicity error
214-217 A4 --- r_[M/H] Source of metallicity
219-237 F19.15 km/s vbroad ?=- Rotational velocity
239-245 F7.4 km/s e_vbroad ?=- Rotational velocity error
247-250 A4 --- r_vbroad Source of rotational velocity
252-272 F21.16 d Timespan Time coverage of observations per star
274-277 I4 --- o_RV velocity measurements per star
279-300 F22.16 --- RVCstd Standard deviation of NZP-corrected radial
velocities per star
302-322 F21.17 --- e_RVCstd Median internal error of NZP-corrected
radial velocities per star
324-345 E22.17 --- RHKpMed ?=- Median value of the chromospheric
activity index RHKp per star
347-367 E21.17 --- e_RHKpMed ?=- Median value of the RHKp uncertainty
(dRHKp) per star
369-388 F20.17 --- SvalueMed Median value of the Mount Wilson S-index
value per star
390-410 F21.18 --- HalphaMed Median value of the H-alpha per star
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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- 14 A14 --- Name Star name
16- 45 A30 --- Simbad Simbad identifier name
47- 63 F17.13 deg RAdeg Right Ascension (J2000)
65- 81 F17.13 deg DEdeg Declination (J2000)
83- 95 F13.5 d BJD Barycentric Julian date
97-109 F13.7 d MJD Modified Julian date (from fits header)
111-124 F14.7 km/s RV Radial velocity (derived)
126-131 F6.2 km/s e_RV Radial velocity error (derived)
133-148 F16.9 km/s RVcor NZP corrected radial velocity
150-156 F7.3 km/s e_RVcor NZP corrCaIIected radial velocity error
158-163 F6.3 km/s CorV NZP correction
165-169 F5.3 km/s e_CorV NZP correction error
171-176 I6 --- Count Median photons per pixel2025
178-181 I4 s ExpTime Exposure time
183-189 F7.4 --- S-value Chromosperic activity index S-index (1)
191-198 F8.5 --- H-alpha ? Chromosperic activity index H-index (2)
200-222 E23.17 --- RHp ?=- Relative chromospheric emission
in the CaII H line
224-245 E22.17 --- e_RHp ?=- Relative chromospheric emission
in the CaII H line error
247-269 E23.17 --- RKp ?=- Relative chromospheric emission
in the CaII K line
271-292 E22.17 --- e_RKp ?=- Relative chromospheric emission
in the CaII K line error
294-316 E23.17 --- RHKp ?=- Relative chromospheric emission
in the CaII H&K lines
318-339 E22.17 --- e_RHKp ?=- Relative chromospheric emission
in the CaII H&K lines error
341-343 F3.1 --- vsiniflag ?=- Rotational velocity flag (3)
345-347 F3.1 --- metflag ?=- Metallicity flag (4)
349-351 F3.1 --- RVflag ?=- Radial velocity flag (5)
353-374 A22 --- koaid The standard file identifier for the Keck
archive
376-380 F5.1 --- snr-esti ?=- Estimated signal-to- noise ratio
(from fits header)
382-396 A15 --- EXQUAL-H HIRES internal quality flag for spectra that
include the CaII H line (6)
398 I1 --- fflux-H ?=- Plateau-like flat flux flag for spectra
that include the CaII H line (6)(7)
400 I1 --- nflux-H ?=- Fluxes below zero flag for spectra that
include the CaII H line (7)
402 I1 --- nwave-H ?=- Folded wavelengths with negative values
flag for spectra that include the
CaII H line (7)
404 I1 --- ccfflag-H Flag for the difference between the CCF RV
we derived and the catalog RV exceeds 3m/s
(Cross-correlation function for spectra that
include the CaII H line) (7)
406-414 F9.5 --- snrmedH ?=- Signal-to-noise ratio per median column
for spectra that include the CaII H line
(from fits header)
416-430 A15 --- EXQUAL-K HIRES internal quality flag for spectra that
include the CaII K line (7)
432 I1 --- fflux-K ?=- Plateau-like flat flux flag for spectra
that include the CaII K line (7)
434 I1 --- nflux-K ?=- Fluxes below zero flag for spectra that
include the CaII K line (7)
436 I1 --- nwave-K ?=- Folded wavelengths with negative values
flag for spectra that include the
CaII K line (7)
438 I1 --- ccfflag-K ?=- Flag for the difference between the CCF RV
we derived and the catalog RV exceeds 3m/s
(Cross-correlation function for spectra that
include the CaII K line) (7)
440-448 F9.5 --- snrmedK ?=- Signal-to-noise ratio per median column
for spectra that include the CaII K line
(from fits header)
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Note (1): Obtained from measurement of the emission reversal at the cores of the
Fraunhofer H and K lines of CaII at 3968Å and 3934Å respectively.
Note (2): A measure of the chromospheric emission component at the Hα
Balmer line of hydrogen at 6563Å (Gomes da Silva et al.
2011A&A...534A..30G 2011A&A...534A..30G). Note that H-index values H≥0.062 are to be
considered with caution (see Section 4 in the paper).
Note (3): vsini flag as follows:
0 = have measurement from catalog
1 = have no measurement from catalog - use 1.0 (instead)
Note (4): Metallicity flag as follows:
0 = have measurement from catalog
1 = have no measurement from catalog - use 0.0 (instead)
Note (5): Radial velocity flag as follows:
0 = have measurement from catalog
1 = have no measurement from catalog - use 0.0 (instead)
Note (6): HIRES internal quality flag: pass, fail and unknown.
Note (7): All flags are defined as follows:
0 = no issue in the spectra (or unvalid values in the case of ccfflagK)
1 = issue detected
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Acknowledgements:
Jerusalem Tamirat Teklu, jerusale.teklu(at)msmail.ariel.ac.il
(End) Jerusalem T. Teklu [Ariel, Israel], Patricia Vannier [CDS] 20-Aug-2025