Results 41 to 50 of about 904 (176)

Mapping Stellar Surfaces. II. An Interpretable Gaussian Process Model for Light Curves

The Astronomical Journal, 2021
The use of Gaussian processes (GPs) as models for astronomical time series data sets has recently become almost ubiquitous, given their ease of use and flexibility.
Rodrigo Luger, Daniel Foreman-Mackey, Christina Hedges   +2 more
doaj   +1 more source

Starspots that induce no temporal variability confound fundamental stellar properties.

, 2018
Longitudinally asymmetric starspots modulate observed stellar flux as stars rotate, an assumption underpinning the majority of stellar rotation studies and gyrochronology.
Gully-Santiago, Michael, Gully-Santiago, Michael (5288437)   +1 more
core   +1 more source

Starspots and photometric noise on observed minus calculated (O–C) diagrams

, 2002
The effects of starspots on the O–C diagrams of eclipsing binaries are investigated, with a special emphasis on contact binaries. It is shown that starspots modulate the O–C differences in a fundamentally different way than real orbital period variations.
A. Kalimeris, H. Rovithis-Livaniou, P. Rovithis   +2 more
core   +2 more sources

Benchmarking pre-main sequence stellar evolutionary tracks using disk-based dynamical stellar masses

Astronomy & Astrophysics
Stellar masses are a fundamental property to understand models of pre-main sequence evolution, but their values derived from Hertzsprung–Russell (HR) diagrams are strongly model dependent.
Zallio Luigi, Vioque Miguel, Andrews Sean M., Empey Aaron, Rosotti Giovanni P., Miotello Anna, Manara Carlo F., Carpenter John M., Deng Dingshan, Kurtovic Nicolás T., Law Charles J., Longarini Cristiano, Paneque-Carreño Teresa, Teague Richard, Villenave Marion, Yen Hsi-Wei, Zagaria Francesco   +16 more
doaj   +1 more source

Impact of stellar spots on the high-resolution transmission spectra of a giant planet around a Sun-like star

Astronomy & Astrophysics
Context. Transmission spectroscopy has enabled the analysis of exoplanet atmospheres. However, a major challenge in this field is the “noise” from host stars, caused by stellar activity such as dark spots and bright plages.
Lucero Jennifer P., Demangeon O. D. S., Cristo E., Dethier W., Santos N. C.   +4 more
doaj   +1 more source

Starspots and active regions on the emission red dwarf star

, 2002
The quasi-simultaneous electrophotometric, polarimetric and spectroscopic observations of the single active spotted star $LQ~Hya$ are presented. The photometric variability of the star can be described completely by a zonal starspots model.
I. Yu. Alekseev, O. V. Kozlova
core   +1 more source

The circumstellar environment of the young, low-mass dipper star JH 223

Astronomy & Astrophysics
Context. Studies of magnetospheric accretion and magnetic field topology in T Tauri stars have advanced over the years, but their applications to fully convective, very-low-mass T Tauri stars remain relatively unexplored. Aims.
Freitas T. P., Bouvier J., Zaire B., Alencar S. H. P., Sousa A. P., Rebull L., Bayo A., Frasca A., Alonso-Santiago J., Grankin K., Contreras Peña C., Cody A. M., Hillenbrand L. A., Carmona A.   +13 more
doaj   +1 more source

Starspot detection and properties [PDF]

Proceedings of the International Astronomical Union, 2012
AbstractI review the currently available techniques for the starspots detection including the one-dimensional spot modelling of photometric light curves. Special attention will be paid to the modelling of photospheric activity based on the high-precision light curves obtained with space missions MOST, CoRoT, and Kepler.
openaire   +1 more source

First Chromospheric Activity and Doppler Imaging Study of PW And Using a New Doppler Imaging Code: SpotDIPy

The Astrophysical Journal, 2023
Measuring the coverage of dark spots on cool stars is important to understanding how stellar magnetic activity scales with the rotation rate and convection zone depth. In this respect, it is crucial to infer surface magnetic patterns on G and K stars, to
Engin Bahar, Hakan V. Şenavcı, Emre Işık, Gaitee A. J. Hussain, Oleg Kochukhov, David Montes, Yue Xiang   +6 more
doaj   +1 more source

Molecules as magnetic probes of starspots [PDF]

Astronomy & Astrophysics, 2015
Stellar dynamo processes can be explored by measuring the magnetic field. This is usually obtained using the atomic and molecular Zeeman effect in spectral lines. While the atomic Zeeman effect can only access warmer regions, the use of molecular lines is of advantage for studying cool objects.
Afram, N., Berdyugina, S. V.
openaire   +2 more sources