相关论文: X-ray Spectroscopy of the Contact Binary VW Cephei

Short-period binaries represent extreme cases in the generation of stellar coronae via a rotational dynamo. Such stars are important for probing the origin and nature of coronae in the regimes of rapid rotation and activity saturation. VW…

Context. Despite the fact that VW Cephei is one of the well-studied contact binaries in the literature, there is no fully consistent model available that can explain every observed property of this system. Aims. Our motivation is to obtain…

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…

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…

A survey of 28 stars using EUV spectra has been conducted to establish the structure of stellar coronae in active binary systems from the EMD, electron densities, and scale sizes. Observations obtained by the EUVE during 9 years of…

Theta 1 Ori E is a young, moderate mass binary system, a rarely observed case of spectral-type G-giants of about 3 Solar masses, which are still collapsing towards the main sequence. We have obtained high resolution X-ray spectra with…

Despite many attempts, the origin of UV emission line and continuum in contact binary stars remains unclear. We present a substantial UV spectroscopic analysis of VW Cephei, a late-type contact binary system, using 46 low-resolution spectra…

Close binary systems undergoing mass transfer or common envelope interactions can account for the morphological properties of some planetary nebulae. The search for close binary companions in planetary nebulae is hindered by the difficulty…

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 present a detailed X-ray analysis and imaging of stellar coronae of five coronally connected eclipsing binaries, namely, 44 Boo, DV Psc, ER Vul, XY UMa, and TX Cnc. Both components of these binaries are found to be active. The X-ray…

Luminous X-ray stars are very often found in visual double or multiple stars. Binaries with periods of a few days possess the highest degree of coronal X-ray activity among regular, non-relativistic stars because of their fast, tidally…

Oscillating Algol-type eclipsing binaries (oEA) are very interesting objects that have three observational features of eclipse, pulsation, and mass transfer. Direct measurement of their masses and radii from the double-lined radial velocity…

We have studied the coronal X-ray emission of the recently discovered short-period eclipsing binary HD 9770 with the BeppoSAX satellite. The data from the Low Energy and Medium Energy Concentrator Spectrometers (LECS & MECS) onboard…

New CCD photometry during 4 successive years from 2005 is presented for the eclipsing binary GW Cep, together with reasonable explanations for the light and period variations. All historical light curves, obtained over a 30-year interval,…

EUVE satellite spectroscopic observations (SW, MW and LW bands covering 80 - 160, 170 - 350 and 450 A with resolutions 0.5, 1 and 2 A) and photometric observations (Deep Sky Survey, broad-band 70 - 140 A) have been obtained for two contact,…

The observation of eclipses during X-rays flares taking place in active cool stars binaries allows us to calculate the position and size of the flares. This information cannot be derived by analyzing the decay of the flares, a frequently…

It is already known that about 10% of central stars of PNe are very short-period binaries (hours to days), which are detected through photometric variations. These must have been formed through common-envelope interactions in initially wide…

The recent observation of high-energy neutrinos from the Galactic plane implies an abundant population of hadronic cosmic-ray sources in the Milky Way. We explore the role of the coronae of accreting stellar-mass black holes as such…

We observed the coronally active eclipsing binary, AR Lac, with the High Energy Transmission Grating on Chandra for a total of 97 ks, spaced over five orbits, at quadratures and conjunctions. Contemporaneous and simultaneous EUV spectra and…

Stellar coronae are believed to be the main birthplace of various stellar magnetic activities. However, the structures and properties of stellar coronae remain poorly understood. Using the Space Weather Modelling Framework with the…