J. A. de Freitas Pacheco

The helium-core mass at the helium flash in low-mass red giant stars: observations and theory

The method developed by Raffelt (1990a,b,c) to estimate a possible increase in the standard values of the helium-core mass at the tip of the red giant branch,

Population synthesis of pulsars: magnetic field effects

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New UBVRI colour distributions in E-type galaxies - I. The data

, from properties of the color-magnitude diagrams of Galactic globular clusters is employed. In the present study, we revise and update Raffelts database, including also constraints from RR Lyrae pulsation, and find that a small increase, by

Status Report of the Schenberg Gravitational Wave Antenna

\Delta\Mc \approx 0.01\pm 0.015 \Msun

The spectrum of Cyg X-1 — A theoretical model

, cannot be ruled out with the present data and evolutionary models. Our new upper limits on

Friedmann-like collapsing radiating sphere

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A spectroscopic study of Nova Centauri 1986

are less restrictive than those previously obtained by Raffelt, as are the corresponding constraints on novel astroparticle phenomena which may affect the evolution of low-mass red giants. Within the estimated uncertainties, however, the standard values of

Gas and dust release rates and color of dust in comets P/Halley (1986 III), P/Giacobini-Zinner (1985 XIII), and P/Hartley-Good (1985 XVII)

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Limits on the early afterglow phase of gamma-ray burst sources from TAROT-1

may also be acceptable. Raffelts method does not rule out a low envelope helium abundance in globular cluster giants, though again the standard values are compatible with the available constraints. The influence of a non-solar ratio for the

Atomic Emission Lines in the Spectrum Observed after the Impact between the L-Fragment of Comet D/Shoemaker-Levy 9 and Jupiter

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