Results 1 to 10 of about 205 (134)
Long-term Doppler imaging of the star XX Trianguli indicates chaotic non-periodic dynamo [PDF]
Nature CommunicationsSunspots are the most well-known manifestations of solar magnetic fields and exhibit a range of phenomena related to the interior dynamo. Starspots are the direct analogs of sunspots on other stars but with the big observational restriction that we ...
K. G. Strassmeier +3 more
doaj +2 more sources
Clinical and Translational Discovery, Volume 2, Issue 4, December 2022., 2022 Backgournd Variability is essential for the efficient functioning of multiple systems in nature. Systems do not function according to rigid rules, easy to determine. The reasons for such behaviour directly affect the design and efficient energy utilization.
Yaron Ilan
wiley +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
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
Massive Stars as the Radiant Queens of the Universe—The Case of ζ Puppis
Universe, 2022 Since the Cosmic Dawn, massive stars have been playing a crucial role as the chemical recycling engines of galaxies that enable the birth of new stars and planetary systems, not only through the strong winds that they exhibit during their relatively ...
Tahina Ramiaramanantsoa +1 more
doaj +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
Progress report on the monitoring active late-type stars in 2005/2006 and the analysis of V523 Cas [PDF]
Serbian Astronomical Journal, 2006 We present the light curve analysis of late-type binary V523 Cas for the season 2005. The spot has been revealed on the secondary. According to theoretical considerations, the spot appeared to be hotter than the surrounding photosphere and located at ...
Zboril M., Đurašević G.
doaj +1 more source
Monitoring active stars 29 Dra, 12 Cam and colour excess of II Peg [PDF]
Serbian Astronomical Journal, 2007 We present the BV light curves analysis of late-type, long-period stars 29 Dra, 12 Cam for the season 2005/2006, and shorter-period star II Peg for the same season.
Zboril M.
doaj +1 more source
Starspot Activity without Pulsation in the Binary System KIC 5444392 Revisited
Universe, 2023 We revisited the short-period (∼1.5 days) binary system KIC 5444392, which shows quasi-period modulated light variations. Previous studies indicated that these variations might be caused by stellar pulsations.
Mengqi Jin +3 more
doaj +1 more source
Differential photometry of EK DRA and 29 DRA [PDF]
Serbian Astronomical Journal, 2005 We report on BVR precise photometry of active late-type stars EK DRA and 29 DRA in the spring of 2004. The analysis suggests a reasonable fit with single spot model for both cases in the season as far as the V-curve is concerned.
Zboril M.
doaj +1 more source