A super-earth at the very nearby GJ 514

A quarter century of spectroscopic monitoring of the nearby M dwarf Gl 514. A super-Earth on an eccentric orbit moving in and out of the habitable zone
https://arxiv.org/abs/2204.06376

Quote :

We investigated the presence of planetary companions around the nearby (7.6 pc) and bright (V=9 mag) early-type M dwarf Gl 514, analysing 540 radial velocities collected over nearly 25 years with the HIRES, HARPS, and CARMENES spectrographs. The data are affected by time-correlated signals at the level of 2-3 ms−1 due to stellar activity, that we filtered out testing three different models based on Gaussian process regression. As a sanity cross-check, we repeated the analyses using HARPS radial velocities extracted with three different algorithms. We used HIRES radial velocities and Hipparcos-Gaia astrometry to put constraints on the presence of long-period companions, and we analysed TESS photometric data. We found strong evidence that Gl 514 hosts a super-Earth on a likely eccentric orbit, residing in the conservative habitable zone for nearly 34% of its orbital period. The planet Gl 514 b has minimum mass mbsinib=5.2±0.9 MEarth, orbital period Pb=140.43±0.41 days, and eccentricity eb=0.45+0.15−0.14. No evidence for transits is found in the TESS light curve. There is no evidence for a longer period companion in the radial velocities and, based on astrometry, we can rule out a ∼0.2 MJup planet at a distance of ∼3−10 au, and massive giant planets/brown dwarfs out to several tens of au. We discuss the possible presence of a second low-mass companion at a shorter distance from the host than Gl 514 b. Gl 514 b represents an interesting science case to study the habitability of planets on eccentric orbits. We advocate for additional spectroscopic follow-up to get more accurate and precise planetary parameters. Further follow-up is also needed to investigate sub \ms and shorter period signals.

Tuomi (2019) also claimed the presence of a planet at this star.

Edit: Fixed link. Thanks Lazarus!

Link to the GJ 514 paper is https://arxiv.org/abs/2204.06376

The Tuomi et al. (2019) candidate is at 15 days. Looks like this is considered activity in the Damasso et al. paper.

Quote :

The MLP of the HIRES RVs (Fig. 5) is dominated by a significant peak at 14.97 d. We note that the peak observed at 15.02 d is likely an alias due to the sampling. We recall that a quite significant peak at 14.9 days is present in the periodogram of the S-index extracted from HIRES spectra, therefore the peaks observed in the RVs are likely related to the first harmonic of P_★,rot, and should be attributed to stellar activity.