Results 21 to 30 of about 904 (176)
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
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
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
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
Starspots as the origin of ultrafast drifting radio bursts from an active M dwarf. [PDF]
Sci AdvDetecting coherent radio bursts from nearby M dwarfs provides opportunities for exploring their magnetic activity and interaction with orbiting exoplanets.
Zhang J +18 more
europepmc +2 more sources
Hunt for Starspots in HARPS Spectra of G and K Stars [PDF]
, 2020 We present a method for detecting starspots on cool stars using the cross-correlation function (CCF) of high-resolution molecular spectral templates applied to archival high-resolution spectra of G and K stars observed with the High Accuracy Radial ...
Hoeijmakers, H. Jens +3 more
core +1 more source
Proceedings of the International Astronomical Union, 2010 AbstractStarspots are being observed with many different techniques but not always with coherent results. In particular not if model-dependent data analysis must be employed, e.g. through two-dimensional spot modelling of one-dimensional photometric light curves. I review the zoo of currently available physical spot parameters, i.e.
openaire +1 more source
Doppler Imaging of Starspots [PDF]
International Astronomical Union Colloquium, 1983 ABSTRACTWe discuss a newly-developed technique for spatially resolving starspots on some of the more rapidly rotating RS CVn stars. Basically, the method uses high resolution, very high signal-to-noise spectral line profiles and exploits the Doppler velocity correspondence between position across the stellar disk and wavelength position across a ...
Steven S. Vogt, G. Donald Penrod
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Highlights of Astronomy, 1986 AbstractThe general methodology to detect and study solar-like surface inhomogeneities on stars is presented. The most significant observations and typical results are discussed with particular emphasis on the inferred physical characteristics of starspots and plages and differential rotation, as compared to solar values.
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The STELLA Robotic Observatory on Tenerife
Advances in Astronomy, Volume 2010, Issue 1, 2010., 2010 The Astrophysical Institute Potsdam (AIP) and the Instituto de Astrofísica de Canarias (IAC) inaugurated the robotic telescopes STELLA‐I and STELLA‐II (STELLar Activity) on Tenerife on May 18, 2006. The observatory is located on the Izaña ridge at an elevation of 2400 m near the German Vacuum Tower Telescope.
Klaus G. Strassmeier +12 more
wiley +1 more source