ar X iv : a st ro - p h / 01 11 57 3 v 1 3 0 N ov 2 00 1 Optical Spectra of Supernovae

ar X iv : a st ro - p h / 01 11 13 6 v 1 7 N ov 2 00 1 1 Active Optics in Modern , Large Optical Telescopes

ar X iv : a st ro - p h / 06 11 03 3 v 1 1 N ov 2 00 6 On the Progenitor of Supernova 1987 A

A previously unpublished ultralow–dispersion spectrum of Sanduleak -69 202, the stellar progenitor of SN 1987A, is presented and the uncertain presupernova evolution of Sanduleak -69 202 is discussed. Subject headings: Supernovae: individual (SN 1987A) — techniques: ultralow– dispersion spectra — Large Magellanic Cloud — supergiants — stars: Sanduleak -69 202

ar X iv : a st ro - p h / 04 11 15 9 v 1 6 N ov 2 00 4 Neutrino Mixing and Nucleosynthesis in Core - Collapse Supernovae

A simple description of core-collapse supernovae is given. Properties of the neutrino-driven wind, neutrino fluxes and luminosities, reaction rates, and the equilibrium electron fraction in supernova environments are discussed. Neutrino mixing and neutrino interactions that are relevant to core-collapse supernovae are briefly reviewed. The values of electron fraction under several evolution sce...

ar X iv : a st ro - p h / 02 11 45 7 v 1 2 0 N ov 2 00 2 Time variation of fundamental constants : two phenomenological models

Time variation of fundamental constants, a strong signal of new physics, is analyzed comparing extant data with two phenomenological models. Results are discussed.

ar X iv : a st ro - p h / 04 11 16 2 v 1 8 N ov 2 00 4 Chandra observations of the recurrent nova IM Nor

The recurrent nova IM Nor was observed twice in X-rays with Chandra ACISS, 1 and 6 months after the optical outburst. It was not detected in the first