Bibcode
Stefanov, A. K.; González Hernández, J. I.; Suárez Mascareño, A.; Rebolo, R.; Nari, N.; Mestre, J. M.; Sousa, S. G.; Tabernero, H. M.; Zapatero Osorio, M.-R.; Figueira, P.; Faria, J. P.; Hobson, M. J.; Silva, A. M.; Castro-González, A.; Santos, N. C.; Sozzetti, A.; Pepe, F.; Cristiani, S.; Lavie, B.; Martins, C. J. A. P.
Bibliographical reference
Astronomy and Astrophysics
Advertised on:
11
2025
Journal
Citations
0
Refereed citations
0
Description
M dwarfs are the most abundant stars in the Galaxy, and their low masses make them natural favourites for exoplanet radial-velocity (RV) searches. Nevertheless, these stars often demonstrate strong stellar activity that is yet to be fully understood. We used high-precision ESPRESSO, HIRES, and HARPS spectroscopy to perform a stellar-activity analysis on the nearby early M dwarf GJ 526 (d = 5.4 pc). We carried out a joint modelling of (i) the stellar rotation in RV, full width at half maximum (FWHM), and Mount Wilson S-index through Gaussian processes; (ii) long-term trends in these three physical quantities; and (iii) RV planetary signals. We constrained the stellar-rotation period to Prot = 48.7 ± 0.3 d, and discovered a weak sinusoidal signature in RV, FWHM, and S-index of period Pcyc = 1680−40+50d. We propose phase-space trajectories between RV and activity indicators as a novel means to visualise and interpret stellar activity. Current evidence does not support planetary companions of GJ 526.
Related projects
Very Low Mass Stars, Brown Dwarfs and Planets
Our goal is to study the processes that lead to the formation of low mass stars, brown dwarfs and planets and to characterize the physical properties of these objects in various evolutionary stages. Low mass stars and brown dwarfs are likely the most numerous type of objects in our Galaxy but due to their low intrinsic luminosity they are not so
Rafael
Rebolo López