We present results on low-resolution mid-infrared spectroscopy of a sample of 70 infrared-luminous galaxies and quasars obtained with the Infrared Spectrograph (IRS) onboard Spitzer. We selected the sample from the European Large Area Infrared Survey (Oliver et al. 2000, Rowan-Robinson et al. 2004), which was carried out with the Infrared Space

Context: Near-Earth asteroid-comet transition object 107P/ (4015) Wilson-Harrington is a possible target of the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) Marco Polo sample return mission. Physical studies of this object are relevant to this mission, and also to understanding its asteroidal or cometary nature

We present the discovery of a new extreme high proper motion object (˜3.5 arcsec/year) which we classify as an ultracool subdwarf with [M/H] ˜ -0.5. It has a formal spectral type of sdM9 but also shows L-type features: while the VO bands are completely absent, it exhibits extremely strong TiO absorption in its optical spectrum. With a radial

The bright nebula NGC 6334 extends nearly 0.4 square degrees across the sky and is located at a distance from the Sun of 1.61 kpc. This region contains some of the most active sites of massive star formation in our Galaxy. Discovered by their bright far-infrared emission associated with radio continuum peaks, these nuclei of activity are aligned

We present a study of the star formation in the giant Hii region NGC5471 in the outskirts of M101. We have performed integrated photometry of the mean emission knots. Stellar population analysis with the code chorizos is compatible with the hypothesis that these regions have at least two different populations. The color-magnitude diagram of the

The study of satellite galaxies can provide information on the merging and aggregation processes which, according to the hierarchical clustering models, form the larger spiral galaxies we observe. With the aim of testing hierarchical models of galaxy formation, we have conducted an observational program which comprises H$alpha$ imaging for both the