相关论文: The continuous period search method and its applic…

The Cepheid Period-Luminosity law is a key rung on the extragalactic distance ladder. However, numerous Cepheids are known to undergo period variations. Monitoring, refining, and understanding these period variations allows us to better…

We report on the results of an extended optical spectroscopic monitoring campaign on the early-type B supergiant HD64760 (B0.5Ib) designed to probe the deep-seated origin of spatial wind structure. This new study is based on high-resolution…

Methods to measure masses of PG1159 stars in order to test evolutionary scenarios are currently based on spectroscopic masses or asteroseismological mass determinations. SDSSJ212531.92-010745.9, a recently discovered PG1159 star in a close…

By controlling instrumental errors to below 10 cm/s, the EXtreme PREcision Spectrograph (EXPRES) allows for a more insightful study of photospheric velocities that can mask weak Keplerian signals. Gaussian Processes (GP) have become a…

To broaden the understanding of classical Cepheid structure, evolution and atmospheres, we have extended our continuing secret lives of Cepheids program by obtaining XMM/Chandra X-ray observations, and Hubble space telescope (HST) / cosmic…

We present analysis of the starspot properties and chromospheric activity on HD 134319 using high precision photometry by TESS in sectors 14-16 (T1), 21-23 (T2) and high-resolution spectroscopy by OHP/ELODIE and Keck/HIRES during years…

We study LQ Hya photometry for 1982-2014 with the carrier fit (CF) -method and compare our results to earlier photometric analysis and recent Doppler imaging maps. We first utilize different types of statistical methods to estimate various…

The NASA Kepler space telescope has detected solar-like oscillations in several hundreds of single stars, thereby providing a way to determine precise stellar parameters using asteroseismology. In this work, we aim to derive the fundamental…

A new method for determining the stellar rotation period is proposed here, based on the detection of starspots during transits of an extra-solar planet orbiting its host star. As the planet eclipses the star, it may pass in front of a…

We present a stroboscopic system developed for optical observations of pulsars and its application in the CLYPOS survey. The stroboscopic device is connected to a GPS clock and provides absolute timing to the stroboscopic shutter relative…

Aims: We investigate the photometric properties of the M7.5 equal-mass binary VHS J1256-1257AB, which, combined with the late-L dwarf VHS J1256-1257 b, forms one of the few young triple systems of ultra-cool dwarfs currently known. Methods:…

We analyzed a Kepler light curve of KIC 8751494, a recently recognized novalike cataclysmic variable in the Kepler field. We detected a stable periodicity of 0.114379(1) d, which we identified as being the binary's orbital period. The…

Context. Studying the spots of late-type stars is crucial for distinguishing between the various proposed dynamo mechanisms believed to be the main cause of starspot activity. For this research it is important to collect observation time…

Active regions on the photosphere of a star have been the major obstacle for detecting Earth-like exoplanets using the radial velocity (RV) method. A commonly employed solution for addressing stellar activity is to assume a linear…

We present radial velocity measurements of the very bright ($V\sim5.7$) nearby F star, DMPP-4 (HD 184960). The anomalously low Ca II H&K emission suggests mass loss from planets orbiting a low activity host star. Periodic radial velocity…

The aim of this work was to use a multi-approach technique to derive the most accurate values possible of the physical parameters of the \delta Sct star HD174966. In addition, we searched for a periodic pattern in the frequency spectra with…

The period-change rate (PCR) of pulsating variable stars is a useful probe of changes in their interior structure, and thus of their evolutionary stages. So far, the PCRs of Classical Cepheids in the Large Magellanic Cloud (LMC) have been…

Through an innovative combination of multiple observing techniques and mod- eling, we are assembling a comprehensive understanding of the pulsation and close environment of Cepheids. We developed the SPIPS modeling tool that combines all…

The high accuracy of space data increased the number of the periodicities determined for pulsating variable stars, but the mode identification is still a critical point in the non-asymptotic regime. We use regularities in frequency spacings…

The expert system for time series analysis of irregularly spaced signals is reviewed. It consists of a number of complementary algorithms and programs, which may be effective for different types of variability. Obviously, for a pure sine…