SIMBAD references

2020RNAAS...4..153D - Research Notes of the AAS, 4, 153 (2020/September-0)

Modeling the Quasiperiodic Radial Velocity Variations of γ Draconis.

DELGADO V.R. and DODSON-ROBINSON S.

Abstract (from CDS):

γ Draconis, a K5III star, showed radial velocity (RV) variations consistent with a 10.7 Jupiter mass planet from 2003 to 2011. After 2011, the periodic signal decayed, then reappeared with a phase shift. Hatzes et al. suggested that γ Dra's RV variations could come from oscillatory convective modes, but did not fit a mathematical model. Here we assess whether a quasi-periodic Gaussian process-appropriate when spots with finite lifetimes trace underlying periodicity-can explain the RVs. We find that a model with only one quasiperiodic signal is not adequate: we require a second component to fit the data. The best-fit model has quasi-periodic oscillations with P1 = 705 days and P2 = 15 days. The 705 day signal may be caused by magnetic activity. The 15 day period requires further investigation.

Abstract Copyright: © 2020. The American Astronomical Society. All rights reserved.

Journal keyword(s): Exoplanets - Radial velocity - Exoplanet detection methods - Stellar activity - Bayesian statistics - Gaussian Processes regression - Stellar rotation

Simbad objects: 2

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2020RNAAS...4..153D and select 'bookmark this link' or equivalent in the popup menu