General properties of Luminous Blue Variables (LBV) have been reviewed by Lamers (1987). The LBV's are all close to the Humphreys-Davidson luminosity upper limit. The semi periods of the photometric microvariations with Delta V is about 0.1m are about twice as large as for normal supergiants of the same L and Teff, and 4-20 times larger than the
Wind variability of LBV starsIsraelian, G. L.121993
Winds Driven by Super-Star Clusters
Here we present a self-consistent stationary solution for spherically symmetric winds driven by massive star clusters under the impact of radiative cooling. We demonstrate that cooling may modify drastically the distribution of temperature if the rate of injected energy approaches a critical value and that the stationary wind solution does notSilich, S. et al.
Winds from Low Mass Stars: impact on the ISM
A large fraction of all stars, after experiencing heavy winds at the end of the Asymptotic Giant Branch (AGB) phase, leave behind a core that is below the Chandrasekhar mass limit. This core eventually photoionizes the stellar ejecta giving birth to a planetary nebula (PN). PN and AGB stars are therefore the remnants of stars that through theirVillaver, E. et al.
X-Ray Jets in Coronal Holes: Numerical Simulation and Hinode Observations
We report on our recent 3D numerical models of the launching of hot, high-speed jets in a coronal hole following the emergence of magnetized plasma from the solar interior. As part of the same research, we have also analyzed Hinode (EIS and XRT) and Soho-MDI observational data of an actual process of flux emergence followed by jet launching in aMoreno-Insertis, F. et al.
X-ray Spectral State is not Correlated with Luminosity in Holmberg II X-1
The ultraluminous X-ray source (ULX) Holmberg II X-1 has been observed over four months in 2009/2010 by the Swift observatory. The source luminosity varied by a factor of up to 14, reaching a maximum 0.3-10 keV luminosity of ~3.0 × 1040 erg s-1. The spectral properties do not vary much over these four months, with only a slight monotonic increaseGrisé, F. et al.
X-ray Transients in M31
On Nov 19, 2001, The Chandra X-ray Observatory surveyed M31 with 5 overlapping very short (1ks) HRC exposures and a single short (5ks) ACIS-S exposure. Preliminary analysis allows us to report the following concerning possible X-ray transients within M31. A new source CXOU J004428.4+415628 (RA=00:44:28.4, DEC=+41:56:28.1, J2000), near the NE spiralGarcia, M. et al.