Hot subdwarfs (sdO/B) are the stripped helium cores of red giants formed via binary interactions. Close hot subdwarf binaries with massive white dwarf...

Aims.We study the optical spectral properties of a sample of stars showing far infrared colours similar to those of well-known planetary nebulae. The large...

We present the results of a spectroscopic study of 37 southern (candidate) γ Doradus stars based on échelle spectra. The observed spectra were cross-correlated...

We present a detailed photometric study of the dwarf irregular galaxy NGC 6822 aimed at investigating the properties of its stellar populations and, in...

Context. Coronal mass ejections (CMEs) are often observed to be accompanied by flare, current sheets, and plasmoids/plasma blobs. 2D and 3D numerical...

Context. Stellar occultation is a powerful technique that allows the determination of some physical parameters of the occulting object. The result depends on...

I have studied the relation between the global star formation activity and the bar structure in a sample of isolated barred galaxies. The star formation...

We have observed the He I D3 λ 5876 Å line as a chromospheric activity indicator in 36 stars (34 F-type and 2 G-type) belonging to the Hyades open cluster, the...

Context: Large surveys such as the Sloan Digital Sky Survey have made large amounts of spectroscopic and photometric data of galaxies available, thereby...