Results 21 to 30 of about 2,749 (159)

Interferometric Imaging of λ Andromedae: Evidence of Starspots and Rotation [PDF]

Astrophysical Journal, 2021
Presented are the first interferometric images of cool starspots on the chromospherically active giant λ Andromedae. Using the Michigan Infra-Red Combiner coupled to the Center for High Angular Resolution Astronomy Array, 26 interferometric observations ...
J. Parks, R. White, F. Baron, J. Monnier, B. Kloppenborg, G. Henry, G. Schaefer, X. Che, E. Pedretti, N. Thureau, M. Zhao, T. T. ten Brummelaar, H. Mcalister, S. Ridgway, N. Turner, J. Sturmann, L. Sturmann   +16 more
semanticscholar   +3 more sources

Starspots as an Explanation for the Mysterious IYJ Continuum Excess Emission in Classical T Tauri Stars [PDF]

Astrophysical Journal
An accurate estimation of the continuum excess emission from accretion spots and inner circumstellar disk regions is crucial for a proper derivation of fundamental stellar parameters in accreting systems.
Facundo Pérez Paolino, J. Bary, L. Hillenbrand, Madison Markham, William J. Fischer   +4 more
semanticscholar   +2 more sources

KIC 6362386: An Eclipsing Binary with γ Doradus–type Pulsations and Starspots

Astronomical Journal
KIC 6362386 is an eclipsing binary system that exhibits both γ Doradus (γ Dor)–type pulsations and starspots. In this study, we investigated this binary system using the Kepler photometry and the spectroscopic data from the Large Sky Area Multi-Object ...
Mengqi Jin, Jian-Ning Fu, Xiao-Bin Zhang, W. Zong, Jia-Xin Wang, Xiao-Yu Ma, Ke-Yu Xing, Hao-Tian Wang   +7 more
semanticscholar   +2 more sources

Sunspots, Starspots, and Elemental Abundances

The Astrophysical Journal, 2017
Element abundances in the solar photosphere, chromosphere, transition region, and corona are key parameters for investigating sources of the solar wind and for estimating radiative losses in the quiet corona and in dynamical events such as solar flares ...
G. Doschek, H. Warren
semanticscholar   +2 more sources

The Effects of Starspots on Spectroscopic Mass Estimates of Low-mass Young Stars [PDF]

Astrophysical Journal, 2021
Magnetic fields and mass accretion processes create dark and bright spots on the surface of young stars. These spots manifest as surface thermal inhomogeneities, which alter the global temperature measured on the stars.
C. Flores, M. Connelley, B. Reipurth, G. Duchêne   +3 more
semanticscholar   +1 more source

On the lithium abundance of the visual binary components ξ Boo A (G8V) and ξ Boo B (K5V)

Astronomische Nachrichten, Volume 343, Issue 9-10, November-December 2022., 2022
Abstract A spectroscopic investigation of the lithium resonance doublet in ξ Boo A and ξ Boo B in terms of both abundance and isotopic ratio is presented. We obtained new R = 130,000 spectra with a signal‐to‐noise ratio (S/N) per pixel of up to 3200 using the 11.8 m LBT and PEPSI.
Klaus G. Strassmeier, Matthias Steffen
wiley   +1 more source

First eROSITA‐TESS results for M dwarfs: Mass dependence of the X‐ray activity rotation relation and an assessment of sensitivity limits

Astronomische Nachrichten, Volume 343, Issue 8, October 2022., 2022
Abstract We present a study of the activity‐rotation relation for M dwarf stars, using new X‐ray data from the ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Russian Spektrum‐Roentgen‐Gamma mission (SRG), combined with photometric rotation periods from the Transiting Exoplanet Survey Satellite (TESS). The stars used in this work
E. Magaudda, B. Stelzer, St. Raetz
wiley   +1 more source

ON SUNSPOT AND STARSPOT LIFETIMES [PDF]

The Astrophysical Journal, 2014
We consider the lifetimes of spots on the Sun and other stars from the standpoint of magnetic diffusion. While normal magnetic diffusivity predicts lifetimes of sunspots that are too large by at least two orders of magnitude, turbulent magnetic diffusivity accounts for both the functional form of the solar empirical spot-lifetime relation and for the ...
S. J. Bradshaw, P. Hartigan
openaire   +2 more sources

Analytic model for photometric variation due to starspots on a differentially rotating star [PDF]

Nippon Tenmon Gakkai obun kenkyu hokoku, 2022
We present an analytic model of the light-curve variation for stars with non-evolving starspots on a differentially rotating surface. The Fourier coefficients of the harmonics of the rotation period are expressed in terms of the latitude of the spot ...
Y. Suto, S. Sasaki, Yuta Nakagawa, O. Benomar   +3 more
semanticscholar   +1 more source

On the parameter refinement of inflated exoplanets with large radius uncertainty based on TESS observations

Astronomische Nachrichten, Volume 343, Issue 3, March 2022., 2022
Abstract We revisited 10 known exoplanetary systems using publicly available data provided by the transiting exoplanet survey satellite (TESS). The sample presented in this work consists of short period transiting exoplanets, with inflated radii and large reported uncertainty on their planetary radii.
Xanthippi Alexoudi
wiley   +1 more source