The stellar parameters were determined using an LTE analysis based on equivalent widths (EW) of iron lines and by imposing excitation and ionization equilibrium. The ARES code (that can be downloaded at http://www.astro.up.pt/~sousasag/ares ) was used to allow automatic and systematic derivation of the stellar parameters. Precise stellar parameters

The iodine gas cell is replaced by the telluric O2 and water vapor lines to calibrate observations of RV stable M dwarfs made with the High Resolution Spectrograph of the Hobby-Eberly Telescope. Radial velocities are to be measured with both iodine lines in the visible and the atmospheric lines in the 6000-8800A region, as a first step in

We study the propagation of waves from the photosphere to the chromosphere of sunspots. From time series of cospatial Ca II H (including its line blends) intensity spectra and polarimetric spectra of Si I λ 1082.7 nm and He I λ 1083.0 nm we retrieve the line-of-sight velocity at several heights. The analysis of the phase difference and

In this contribution, I review what we have learnt about macroturbulent broadening in the last decade and present first results of a long term observational project aimed at investigating the possible connection between this spectroscopic feature and the stellar variability phenomena and oscillations.

Context. TMR-1C is a candidate protoplanet that lies at a separation of about 10” (~1000 AU) from the Class I protobinary TMR-1 (IRAS 04361+2547) located in the Taurus molecular cloud. A narrow filament-like structure was observed in the discovery HST/NICMOS images, extending southeast from the central proto-binary system towards TMR-1C, suggesting

Aims: The determination of reliable distances to planetary nebulae (PNe) is a major difficulty in the study of this class of objects in the Galaxy. The availability of new photometric surveys such as IPHAS (the INT/WFC photometric Hα survey of the northern Galactic plane) covering large portions of the sky provide an opportunity to apply the so