To be able to detect a biosphere in an extrasolar planet, life in that planet should have been able to alter the original composition of the planetary atmosphere. In this way, an external observer could detect the chemical disequilibrium introduced by living organisms in the planet. The earthshine technique has allowed us to determine the best disk

The transient LMXB and 11 Hz pulsar currently in outburst in Terzan 5 (ATEL #2919, #2920, #2922, #2924, #2932) has been recently observed to show at least one eclipse of 511 s duration (ATEL #2929). We have checked the Chandra lightcurves (readout streak and dust-scattered halo) from the 2000 July 24 observation (Heinke et al. 2003, ApJ, 590, 809)

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By cross-correlating templates constructed from the Two Micron All Sky Survey Extended Source Catalog with the first-year data from the Wilkinson Microwave Anisotropy Probe (WMAP), we search for the thermal Sunyaev-Zel'dovich (tSZ) signature induced by hot gas in the local universe. Assuming that galaxies trace the distribution of hot gas, we

The numerical solution of the idealized, but self-consistent, LTE atmosphere problem posed by the authors has been used to introduce the effect of multiple scattering on the temperature gradient, the spectral distribution of the observed flux and the intensity discontinuities. In the theoretical consideration of the problem, the nature of

By combining the C III λλ1906+1909 with the C II λ4267 line intensities it is possible to determine T(C++); this temperature is, in general, considerably smaller than T(O++), the temperature derived from the O III λ4363 to λ5007 intensity ratio. The authors study possible causes for this difference. They show that in the presence of spatial