Related papers: AB Dor: Coronal imaging and activity cycles
Although chromospheric activity cycles have been studied in a larger number of late-type stars for quite some time, very little is known about coronal activity-cycles in other stars and their similarities or dissimilarities with the solar…
Using the archival ROSAT PSPC observations, AB Dor is found to be variable in X-rays. The periodic variations are consistent with previously reported rotational period of 0.514 days. The average spectrum of AB Dor is best represented with…
We study the chromosphere and corona of the ultra-fast rotator AB Dor A at high temporal and spectral resolution using simultaneous observations with XMM-Newton in the X-rays, VLT/UVES in the optical, and the ATCA in the radio. Our optical…
The Chandra X-ray observatory monitored the single cool star, AB Doradus, continuously for a period lasting 88ksec (1.98 Prot) in 2002 December with the LETG/HRC-S. The X-ray lightcurve shows significant rotational modulation. It can be…
A fine analysis of spectral line widths and Doppler shifts employing Fourier transform and cross-correlation techniques has been applied to Chandra HETG spectra obtained in 1999 October of the rapidly rotating young star AB Doradus in order…
We obtain contemporaneous observations of the surface and corona of AB Dor using ground-based circularly polarised spectra from the Anglo-Australian Telescope and X-ray data from the Chandra satellite. The ground-based data are used to…
X-ray spectra of the late-type star AB Dor, obtained with the XMM-Newton satellite are analysed. AB Dor was particularly active during the observations. An emission measure reconstruction technique is employed to analyse flare and quiescent…
Our study focuses on analysing the coronal, transition and chromospheric activity of four rapidly rotating stars located within 50 pc in the solar neighbourhood. We have used the multi-wavelength capabilities of AstroSat, to investigate the…
Chromospheric activity cycles are common in late-type stars; however, only a handful of coronal activity cycles have been discovered. \ihor\ is the most active and youngest star with known coronal cycles. It is also a young solar analog,…
The young active star AB Dor (K1 IV-V) has been observed 16 times in the last three years with the XMM-Newton and Chandra observatories, totalling 650 ks of high-resolution X-ray spectra. The XMM/RGS observations with the highest and lowest…
We use X-ray observations of the nearby binaries 61 Cyg A/B (K5V and K7V) and Alpha Cen A/B (G2V and K1V) to study the long-term evolution of magnetic activity in weakly to moderately active G + K dwarfs over nearly a decade. Specifically…
We probe the relationship between surface magnetic fields and the X-ray emitting corona in the rapidly rotating star AB Dor. Circularly polarised spectra have been inverted to produce a surface (photospheric) magnetic field map. This…
We present updated results from the ongoing XMM-Newton monitoring program of moderately active, solar-like stars to investigate stellar X-ray activity cycles; here we report on the binary systems Alpha Cen A/B and 61 Cyg A/B. For 61 Cyg A…
We present the analyses of intense X-ray flares detected on the active fast rotator AB Dor using observations from the XMM-Newton. A total of 21 flares are detected, and 13 flares are analysed in detail. The total X-ray energy of these…
The Chandra X-ray observatory monitored the single cool star, AB Doradus, continuously for a period lasting 88 ksec (1.98 Prot) in 2002 December with the LETG/HRC-S. The X-ray lightcurve shows rotational modulation, with three peaks that…
Context: The fast rotator, pre-main sequence star AB Dor A is a strong and persistent radio emitter. The extraordinary coronal flaring activity is thought to be the origin of compact radio emission and other associated phenomena as large…
The long-term, high precision photometry delivered by the Transiting Exoplanet Survey Satellite (TESS) enables us to gain new insight into known and hitherto well-studied stars. In this paper, we present the result of our TESS study of the…
We present more than 1000-day long photometry of EY Draconis in BV(RI)C passbands. The changes in the light curve are caused by the spottedness of the rotating surface. Modelling of the spotted surface shows that there are two large active…
The active late-type star AB Doradus was observed in February 1996 with the Goddard High Resolution Spectrograph of the Hubble Space Telescope using the low resolution G140L grating. The observations covered one half of the star's rotation…
The relation between magnetic activity and rotation in late-type stars provides fundamental information on stellar dynamos and angular momentum evolution. Rotation/activity studies found in the literature suffer from inhomogeneity in the…