J/AJ/162/61 Radial velocity follow up of Barnard's star with HPF (Lubin+, 2021)
Stellar activity manifesting at a one-year alias explains Barnard b as a false
positive.
Lubin J., Robertson P., Stefansson G., Ninan J., Mahadevan S., Endl M.,
Ford E., Wright J.T., Beard C., Bender C., Cochran W.D., Diddams S.A.,
Fredrick C., Halverson S., Kanodia S., Metcalf A.J., Ramsey L., Roy A.,
Schwab C., Terrien R.
<Astron. J., 162, 61-61 (2021)>
=2021AJ....162...61L 2021AJ....162...61L (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets; Stars, M-type; Radial velocities; Spectra, infrared
Keywords: Exoplanet astronomy; Stellar activity
Abstract:
Barnard's star is among the most studied stars given its proximity to
the Sun. It is often considered the radial velocity (RV) standard for
fully convective stars due to its RV stability and equatorial decl.
Recently, an Msini=3.3M⊕ super-Earth planet candidate with a
233day orbital period was announced by Ribas et al. New observations
from the near-infrared Habitable-zone Planet Finder (HPF) Doppler
spectrometer do not show this planetary signal. We ran a suite of
experiments on both the original data and a combined original + HPF
data set. These experiments include model comparisons, periodogram
analyses, and sampling sensitivity, all of which show the signal at
the proposed period of 233days is transitory in nature. The power in
the signal is largely contained within 211 RVs that were taken within
a 1000 day span of observing. Our preferred model of the system is one
that features stellar activity without a planet. We propose that the
candidate planetary signal is an alias of the 145day rotation period.
This result highlights the challenge of analyzing long-term,
quasi-periodic activity signals over multiyear and multi-instrument
observing campaigns.
Description:
Habitable Zone Planet Finder (HPF) is a high-resolution (R∼55000) NIR
spectrograph on the 10m Hobby-Eberly Telescope (HET), covering the
Doppler-information-rich z, Y, and J bands from 810 to 1280nm. HPF has
an NIR laser-frequency comb (LFC) calibrator, which has been shown to
enable ∼20cm/s calibration precision in 10minute bins and 1.53m/s RV
precision on-sky on Barnard's star over an 3 month baseline. In this
paper, we extend this baseline to 856 days.
Objects:
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RA (2000) DE Designation(s) (Period)
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17 57 48.50 +04 41 36.1 GJ699 = NAME Barnard's star (P=233d)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 31 118 HPF RV measurements of Barnard's Star
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See also:
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
J/ApJS/200/15 : HARPS-TERRA project. I. (Anglada-Escude+, 2012)
J/A+A/557/L10 : Rotation periods of 12000 Kepler stars (Nielsen+, 2013)
J/ApJ/764/131 : Long-term monitoring of Barnard's star velocity (Choi+, 2013)
J/A+A/566/A66 : Correlation logR'HK with logIHα (Gomes da Silva+, 2014)
J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)
J/ApJ/807/45 : Potentially habitable planets orbit. M dwarfs (Dressing+, 2015)
J/ApJ/821/93 : Rotation & Galactic kinematics of mid M dwarfs (Newton+, 2016)
J/MNRAS/472/1618 : Kepler study of starspot lifetimes (Giles+, 2017)
J/MNRAS/474/2094 : Inferring probabilistic stellar rotat. per. (Angus+, 2018)
J/other/Nat/563.365 : Barnard's star radial velocity curve (Ribas+, 2018)
J/MNRAS/484/L8 : Correcting HIRES/Keck RVs systematic errors (Tal-Or+, 2019)
J/A+A/636/A74 : HARPS radial velocity database (Trifonov+, 2020)
J/A+A/639/A77 : Proxima Cen RV, FWHM and fluxes (Suarez Mascareno+, 2020)
J/AJ/159/100 : Flux & RVs of the dwarf G9-40 with K2 & HPF (Stefansson+, 2020)
J/A+A/649/A6 : Gaia Catalogue of Nearby Stars -GCNS (Gaia collaboration, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD [2458234/2459092] Barycentric Julian Date
15- 20 F6.3 m/s RVel [-7.55/3.9] Radial velocity
22- 26 F5.3 m/s e_RVel [0.6/4] Uncertainty in RVel
28- 31 A4 --- Split Split code (1)
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Note (1): The HPF data is designated as "pre" or "post" with respect to the
planned instrument thermal cycle of August 2018.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 18-Nov-2021