相关论文: Automated photometry of $\gamma$ Cassiopeiae:the l…
In this paper results from the optical photometric observations of the pre-main-sequence star V1180 Cas are reported. The star is a young variable associated with the dark cloud Lynds 1340, located at a distance of 600 pc from the Sun in…
We report the discovery of a new 13th magnitude variable in Cassiopeia close to the variable KP Cas. Analysis of 6 days of intensive photometry shows a regular, near sinusoidal modulation with an amplitude of 0.024 magnitudes and a period…
The recent detection of a hard X-ray component in the supernova remnant Cassiopeia A is interpreted as synchrotron emission from electrons accelerated to energies up to 40 TeV (Allen et al., 1997). It is therefore tempting to consider TeV…
We report on observations of the supernova remnant Cassiopeia A in the energy range from 100 MeV to 100 GeV using 44 months of observations from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. We perform a detailed…
Recently, Tiwari, Chaubey, & Pandey (2007) detected the bright component of the visual binary HD151878 to exhibit rapid photometric oscillations through a Johnson B filter with a period of 6 min (2.78 mHz) and a high, modulated amplitude up…
We have examined soft (<2keV) "dips" in six archival XMM-Newton observations of gamma Cas (B0.5IV e) for "soft dips" (< 2keV) in X-ray light curves. We find that such events are sometimes accompanied by minor, near-simultaneous dips in the…
Cassiopeia A (Cas A) supernova remnant shows strong radiation from radio to gamma-ray bands. The mechanism of gamma-ray radiation in Cas A and its possible contribution to PeV cosmic rays are still under debate. The X-ray imaging reveals an…
Supernova remnants (SNRs) have long been considered the leading candidates for the accelerators of cosmic rays within the Galaxy through the process of diffusive shock acceleration. The connection between SNRs and cosmic rays is supported…
Massive stars are rare but of paramount importance for their immediate environment and their host galaxies. They lose mass from their birth through strong stellar winds up to their spectacular end of their lives as supernovae. The mass loss…
Near-infrared interferometers have recently imaged a number of rapidly rotating A-type stars, finding levels of gravity darkening inconsistent with theoretical expectations. Here, we present new imaging of both a cooler star {\beta} Cas…
We report time-resolved VR-band CCD photometry of the eclipsing binary RZ Cas obtained with 38-cm Cassegrain telescope at the Crimean Astrophysical Observatory during July 2004 - October 2005. Obtained lightcurves clearly demonstrates rapid…
V909 Cas is a little-studied example of a \b{eta} Cep pulsating variable located in the OB association Cas OB8 in the Perseus spiral arm of the Milky Way. Photometric observations in 2016-7 provided 30 new times of pulsation extrema and…
We present new optical spectroscopy and photometry, 2MASS infrared observations and 24 years of combined AAVSO and AFOEV photometry of the symbiotic star candidate \ae. The long-term light curve is characterized by outbursts lasting several…
We present the 2.4-45 micrometer ISO-SWS spectrum of the Be star gamma Cas (B0.5 IVe). The spectrum is characterised by a thermal continuum which can be well fit by a power-law S_nu ~ nu^0.99 over the entire SWS wavelength range. For an…
gamma-Cas stars constitute a subgroup of Be stars showing unusually hard and bright X-ray emission. In search for additional peculiarities, we analyzed the TESS lightcurves of 15 gamma-Cas analogs. Their periodograms display broad frequency…
We have performed the first detailed spatially resolved spectroscopy of Cas A in the 1.6-10 keV energy range, using data taken with the MECS spectrometer on board the BeppoSAX Observatory. We performed a spatial deconvolution of the data…
We present the first results on the hard X-ray continuum image (up to 15 keV) of the supernova remnant Cas A measured with the EPIC cameras onboard XMM-Newton. The data indicate that the hard X-ray tail, observed previously, that extends to…
In this paper we present recent image and spectral data of Cas-A obtained with XMM-Newton and BeppoSAX. Analysis of the hard X-ray continuum does not support an interpretation of the hard X-radiation as synchrotron emission produced in the…
We present new optical time-resolved photometry and medium-resolution spectroscopy of V2187 Cyg. We confirm its classification as a beta Cephei star based on sinusoidal light variations with a period of 0.2539 days and mean amplitudes of…
We report the discovery of faint very high energy (VHE, E>100 GeV) gamma-ray emission from the radio galaxy Centaurus A in observations performed with the H.E.S.S. experiment, an imaging atmospheric Cherenkov telescope array consisting of…