Aims: We propose and explore a new diagnostic technique based upon the linear polarization emitted in Hanle-sensitive lines in disk-integrated stars where a dipolar magnetic field breaks the rotational symmetry of the resonance scattering polarization Methods: A star with a simple dipolar field and a 1-0 spectral line were used to compute

At 04:08:54 UT on 2007 October 25, the Burst Alert Telescope on-board Swift detected GRB 071025 and performed a rapid slew to the GRB location, beginning observations with the X-Ray Telescope at 146s after the trigger. The robotic IR observatory PAIRITEL consists of the 1.3-m Peters Telescope at Mt. Hopkins, Arizona, formerly used for the Two

For the first time, subelectron readout noise has been achieved with a camera dedicated to astronomical wavefront-sensing applications. The OCam system demonstrated this performance at a 1300 Hz frame rate and with 240 × 240 pixel frame size. ESO and JRA2 OPTICON jointly funded e2v Technologies to develop a custom CCD for adaptive optics (AO)

We present 93 photoelectric minima observations of 25 eclipsing binaries.

Context. Knowledge of the mass function in open clusters constitutes one way to critically examine the formation mechanisms proposed to explain the existence of low-mass stars and brown dwarfs. Aims: The aim of the project is to determine as accurately as possible the shape of the mass function across the stellar/substellar boundary in the young (5

Context. There is a continuing debate as to the form of the outer disc of the Milky Way galaxy, which has important implications for understanding the Galaxy's formation. Stars are known to exist at a galacto-centric distance of at least 20 kpc. However, there is much debate as to whether these stars can be explained as part of the disc or whether