We detected the nucleus of Comet 22P/Kopff at 4.87 AU from the Sun with the two IRS peak-up cameras of the Spitzer Space Telescope on April 19, 2007. Using the thermal model of [Groussin, O., and 15 colleagues, 2007. Icarus 187, 16 25], we derive a nucleus size of 1.89±0.16 km, in agreement with [Lamy, P., Toth, I., Jorda, L., Groussin, O., A'Hearn

SW Sextantis stars are a relatively large group of cataclysmic variables (CVs) which plays a fundamental role in our understanding of CV structure and evolution. Very little is known about the properties of their accreting white dwarfs and their donor stars, as the stellar components are usually outshone by an extremely bright accretion flow

Context: Bars are very common in the centre of the disc galaxies, and they drive the evolution of their structure. The state-of-the-art imaging and redshift surveys of galaxies allow us to study the relationships between the properties of the bars and those of their hosts in statistically significant samples. Aims: A volume-limited sample of 2106

Aims: We investigate the dual-dust chemistry phenomenon in planetary nebulae (PNe) and discuss reasons for its occurrence, by analyzing Spitzer/IRS spectra of a sample of 40 Galactic PNe among which 26 belong to the Galactic Bulge (GB). Methods: The mixed chemistry is derived from the simultaneous detection of Polycyclic Aromatic Hydrocarbon (PAH)

The study of young stellar populations has revealed that most stars are in binary or higher order multiple systems. In this study, the influence on the stellar initial mass function (IMF) of large quantities of unresolved multiple massive stars is investigated by taking into account the stellar evolution and photometrically determined system masses

The radial velocity technique is commonly used to classify transiting exoplanet candidates. However, stars are intrinsically noisy in radial velocity. No good description of this noise has yet been proffered, although activity in general has been suggested as the source, making it impossible to evaluate its effect on signal detection. In this