相关论文: Revisiting the correlation between stellar activit…
Recently Knutson et al. (2010) have demonstrated a correlation between the presence of temperature inversions in the atmospheres of hot Jupiters, and the chromospheric activity levels of the host stars. Here we show that there is also a…
The activity levels of stars are influenced by several stellar properties, such as stellar rotation, spectral type and the presence of stellar companions. In analogy to binaries, planetary companions are also thought to be able to cause…
The chromospheric activity index logR'HK of stars hosting transiting hot Jupiters appears to be correlated with the planets' surface gravity. One of the possible explanations is based on the presence of condensations of planetary evaporated…
We have determined new statistical relations to estimate the fundamental atmospheric parameters of effective temperature and surface gravity, using MK spectral classification, and vice versa. The relations were constructed based on the…
Chromospheric activity monitoring of a wide range of cool stars can provide valuable information on stellar magnetic activity and its dependence on fundamental stellar parameters such as effective temperature and rotation.We compile a…
Empirical correlations between stellar parameters such as rotation or radius and magnetic activity diagnostics require estimates of the effective temperatures and the stellar radii. The aim of this study is to propose simple methods that…
Exoplanets play an important role in understanding the mechanics of planetary system formation and orbital evolution. In this context the correlations of different parameters of the planets and their host star are useful guides in the…
We investigate whether magnetic interaction between close-in giant planets and their host stars produce observable statistical enhancements in stellar coronal or chromospheric activity. New Chandra observations of 12 nearby (d<60 pc)…
The CoRoT satellite has made available high precision photometric observations of a large number of stars of different spectral types. Continuous photometric time series allow the characterization of stellar microvariability in a systematic…
The Kepler mission has been providing high-quality photometric data leading to many breakthroughs in the exoplanet search and in stellar physics. Stellar magnetic activity results from the interaction between rotation, convection, and…
This paper proposes the idea that the observed dependence of stellar activity cycles on rotation rate can be a manifestation of a stronger dependence on the effective temperature. Observational evidence is recalled and theoretical arguments…
The re-emission in the cores of the Ca II H & K and H$\alpha$ lines, are well known proxies of stellar activity. However, these activity indices probe different activity phenomena, the first being more sensitive to plage variation, while…
In asteroseismology an important diagnostic of the evolutionary status of a star is the small frequency separation which is sensitive to the gradient of the mean molecular weight in the stellar interior. It is thus interesting to discuss…
Recent analyses of low-mass eclipsing binary stars have unveiled a significant disagreement between the observations and the predictions of stellar structure models. Results show that theoretical models underestimate the radii and…
To detect stellar activity cycles and study the possible star-planet interactions (SPI's), we have developed both HK$\alpha$ and SPI-HK$\alpha$ projects since 1999 and 2012 respectively. In this work, we present preliminary results of…
We measured the chromospheric activity of the four hot Jupiter hosts WASP-43, WASP-51/HAT-P-30, WASP-72 & WASP-103 to search for anomalous values caused by the close-in companions. The Mount Wilson Ca II H&K S-index was calculated for each…
Effective temperatures, surface gravities, and iron abundances were derived for 109 stars observed by the K2 mission using equivalent width measurements of Fe I and Fe II lines. Calculations were carried out in LTE using Kurucz model…
It has been proposed that magnetic activity could be enhanced due to interactions between close-in massive planets and their host stars. In this article, I present a brief overview of the connection between stellar magnetic activity and…
We used four known chromospheric activity indicators to measure long-term activity variations in a sample of 23 M-dwarf stars from the HARPS planet search program. We compared the indices using weighted Pearson correlation coefficients and…
Close-in massive planets interact with their host stars through tidal and magnetic mechanisms. In this paper, we review circumstantial evidence for star-planet interaction as revealed by the photospheric magnetic activity in some of the…