We present a pulsational stability analysis of hot post-asymptotic giant branch (AGB) H-deficient pre-white dwarf stars with active He-burning shells. The stellar models employed are state-of-the-art equilibrium structures representative of PG1159 stars derived from the complete evolution of the progenitor stars, through the thermally pulsing AGB

Context: Magnetohydrodynamic (MHD) waves are often reported in the solar atmosphere and usually classified as slow, fast, or Alfvén. The possibility that these waves have mixed properties is often ignored. Aims: The goal of this work is to study and determine the nature of MHD kink waves. Methods: This is done by calculating the frequency, the

Here, we discuss the mechanical feedback that massive stellar clusters provide to the interstellar medium of their host galaxy. We apply an analytic theory developed in a previous study for M82-A1 to a sample of 10 clusters located in the central zone of the starburst galaxy M82, all surrounded by compact and dense H II regions. We claim that the

Available from the Minor Planet Center.

Available from the Minor Planet Center.

The new transient LMXB in NGC 6440 (CXOGlb J174852.7-202124; Atel #2139) is declining rapidly. RXTE observed NGC 6440 on July 30 (18:47 to 19:26 TT). The PCA top-layer spectrum is well fit with an absorbed power-law of photon index 2.2+-0.1, with N_H set to 6e21 cm^-2 (as found by Chandra). The inferred 0.5-10 keV luminosity is 4e35 ergs/s, a