The uncombed penumbral model proposed by Solanki & Montavon (cite{sol93a}) is used to understand some recent observational results found in penumbrae. This model uses a penumbral magnetic field structured into horizontal flux tubes embedded in a more vertical background field. A modified version of this model, with a weaker field strength in the

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We present the results of optical/near-IR observations carried out in the period Dec 1998-Dec 1999 at Spanish, Indian and New Zealand observatories. Most of the searches proved to be unfruitful, in spite of the rapid follow-up observations, starting 3-24 hr after the events. This indicates that a significant fraction of the bursts occur in high

An improved error box of GRB 970815 has been reported very recently (Smith et al.1999). This error box is consistent with the decaying X-ray source detected by ROSAT, which strongly supports the source as the GRB X-ray afterglow. We report a re-analysis of the follow up observations performed in 1997 containing the improved RXTE error box. No

In this paper we present the second and final part of a large and photometrically homogeneous CCD color-magnitude diagram (CMD) data base, comprising 52 nearby Galactic globular clusters (GGC) imaged in the V and I bands. The catalog has been collected using only two telescopes (one for each hemisphere). The observed clusters represent 75% of the

We present the results of optical/IR observations obtained in the period June-October 1998. Images in the Gunn-z band were serendipitously taken just 3 days after the giant burst that took place on 27 Aug 1998. .