相关论文: Mitigating stellar activity jitter with different …

Stellar variability is a key obstacle in reaching the sensitivity required to recover Earth-like exoplanetary signals using the radial velocity (RV) detection method. To explore activity signatures in Sun-like stars, we present SolAster, a…

Given that low-mass stars have intrinsically low luminosities at optical wavelengths and a propensity for stellar activity, it is advantageous for radial velocity (RV) surveys of these objects to use near-infrared (NIR) wavelengths. In this…

Due to their higher planet-star mass-ratios, M dwarfs are the easiest targets for detection of low-mass planets orbiting nearby stars using Doppler spectroscopy. Furthermore, because of their low masses and luminosities, Doppler…

(Abridged) Aims: Systematic surveys to search for exoplanets have been mostly dedicated to solar-type stars sofar. We developed in 2004 a method to extend such searches to earlier A-F type dwarfs and started spectroscopic surveys to search…

Since identifying the gap in the H-R Diagram (HRD) marking the transition between partially and fully convective interiors, a unique type of slowly pulsating M dwarf has been proposed. These unstable M dwarfs provide new laboratories in…

The aim of the present study is to determine the Li abundances for a large set of the FGK dwarfs and to analyse the connections between the Li content, stellar parameters, and activity. Atmospheric parameters, rotational velocities and Li…

The radial velocity (RV) technique is a powerful tool for detecting extrasolar planets and deriving mass detection limits that are useful for constraining planet pulsations and formation models. Detection limit methods must take into…

The distortions of absorption line profiles caused by photospheric brightness variations on the surfaces of cool, main-sequence stars can mimic or overwhelm radial velocity (RV) shifts due to the presence of exoplanets. The latest…

Large Low Earth Orbit (LEO) constellations (e.g., Starlink and Iridium) significantly increase the likelihood of transient, high-power interference events at ground receivers. This report presents SatTrack, a GUI-driven simulation framework…

Quantifying stellar parameters and magnetic activity for cool stars in double-lined spectroscopic binaries (SB2) is not straightforward, as both stars contribute to the observed composite spectra and are likely variable. Disentangled…

Stellar activity and planetary effects induce radial velocity (RV) offsets and cause temporal distortions in the shape of the stellar line profile. Hence, accurately probing the stellar line profile offers a wealth of information on both…

The hunt for Earth analogue planets orbiting Sun-like stars has forced the introduction of novel methods to detect signals at, or below, the level of the intrinsic noise of the observations. We present a new global periodogram method that…

Metal hydrides and oxides are important species in hot-Jupiters since they can affect their energy budgets and the thermal structure of their atmospheres. One such species is VO, which is prominent in stellar M-dwarf spectra. Evidence for…

Mid-infrared atomic and ionic line ratios measured in spectra of pre-main sequence stars are sensitive indicators of the hardness of the radiation field impinging on the disk surface. We present a low-resolution Spitzer IRS search for [Ar…

In G dwarfs, the surface distribution, coverage and lifetimes of starspots deviate from solar-like patterns as the rotation rate increases. We set up a numerical platform which includes the large-scale rotational and surface flow effects,…

Here, we present a set of time-dependent 3D RMHD simulations of a M-dwarf star representative of AD Leo, which extend from the upper convection zone into the chromosphere. The 3D model atmospheres are characterized by a very dynamic and…

The inhibition of small-scale convection in the Sun dominates the long-term radial velocity (RV) variability: it therefore has a critical effect on light exoplanet detectability using RV techniques. We here extend our previous analysis of…

A new generation of dedicated Doppler spectrographs will attempt to detect low-mass exoplanets around mid-late M stars at near infrared (NIR) wavelengths, where those stars are brightest and have the most Doppler information content. A…

Stellar active regions, including spots and faculae, can create radial velocity (RV) signals that interfere with the detection and mass measurements of low mass exoplanets. In doing so, these active regions affect each spectral line…

A ring electrode of an RRDE setup is often used to detect a redox active specie produced at the disk electrode. It is especially useful when some side processes occur at the disk (e.g. passivation film growth) along with the main…