Stellar Activity Manifesting at a One-year Alias Explains Barnard b as a False Positive

@article{Lubin2021StellarAM,
  title={Stellar Activity Manifesting at a One-year Alias Explains Barnard b as a False Positive},
  author={Jack Lubin and Paul Robertson and Gudmundur Stef{\'a}nsson and Joe P. Ninan and Suvrath Mahadevan and Michael Endl and Eric B. Ford and Jason T. Wright and Corey Beard and Chad F. Bender and William D. Cochran and Scott A. Diddams and Connor Fredrick and Samuel Halverson and Shubham Kanodia and Andrew J. Metcalf and Lawrence W. Ramsey and Arpita Roy and Christian Schwab and Ryan C. Terrien},
  journal={The Astronomical Journal},
  year={2021},
  volume={162}
}
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 233 day 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… 
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References

SHOWING 1-10 OF 96 REFERENCES
Stellar activity analysis of Barnard’s Star: Very slow rotation and evidence for long-term activity cycle
The search for Earth-like planets around late-type stars using ultra-stable spectrographs requires a very precise characterization of the stellar activity and the magnetic cycle of the star, since
Stellar activity mimics a habitable-zone planet around Kapteyn's star
Kapteyn's star is an old M subdwarf believed to be a member of the Galactic halo population of stars. A recent study has claimed the existence of two super-Earth planets around the star based on
Prospects for detecting the astrometric signature of Barnard’s Star b
A low-amplitude periodic signal in the radial velocity (RV) time series of Barnard’s Star was recently attributed to a planetary companion with a minimum mass of ~3.2 M⊕ at an orbital period of ~233
Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581
TLDR
Reexamination of the radial velocity signals from a famous exoplanet system demands demotion of terrestrial candidates, as well as measuring stellar activity using the Hα line, which greatly diminishes the signal of GJ 581d while significantly boosting the signals of the other known super-Earth planets.
High-cadence spectroscopy of M-dwarfs – II. Searching for stellar pulsations with HARPS
Stellar oscillations appear all across the Hertzsprung–Russell diagram. Recent theoretical studies support their existence also in the atmosphere of M dwarfs. These studies predict for them short
Habitable Zones Around Main-Sequence Stars: New Estimates
Identifying terrestrial planets in the habitable zones (HZs) of other stars is one of the primary goals of ongoing radial velocity (RV) and transit exoplanet surveys and proposed future space
Planets and stellar activity: hide and seek in the CoRoT-7 system
Since the discovery of the transiting super-Earth CoRoT-7b, several investigations have yielded different results for the number and masses of planets present in the system, mainly owing to the
Disentangling Planets and Stellar Activity for Gliese 667C
Gliese 667C is an M1.5V star with a multi-planet system, including planet candidates in the habitable zone (HZ). The exact number of planets in the system is unclear, because the existing radial
Rotation Periods of 34,030 Kepler Main-Sequence Stars: The Full Autocorrelation Sample
We analyzed 3 years of data from the Kepler space mission to derive rotation periods of main-sequence stars below 6500 K. Our automated autocorrelation-based method detected rotation periods between
Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the
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