Recent Talks

CANARY is a technical demonstrator for the proposed EAGLE instrument for European ELT. EAGLE will have twenty Integral Field Units patrolling a 5 arcminute field and requires a new form of adaptive optics to provide the required image quality for its 0.0375 arcsec image sampling: Laser Guide Star Multi-Object AO. This entails several significant technical innovations: open-loop control, atmospheric tomography, and new calibration methods. The CANARY demonstrator is currently in its first, natural guide star, phase, and the first results have been obtained on sky. CANARY Phase A is described and the first results are presented. The next, laser guide star, phase is then outlined.

Fibrils are thin elongated features visible in the solar chromosphere in and around magnetized regions. Because of their visual appearance they have been traditionally considered a tracer of the magnetic field lines. In this work we challenge that notion for the first time by comparing their orientation to that of the magnetic field, obtained via high-resolution spectro-polarimetric observations of Ca II lines. The short answer to the question posed in the title is that mostly yes, but not always.

Recent observations of the rotation curve of M31 show a rise of the outer part that cannot be understood in terms of standard dark matter models or perturbations of the galactic disc by M31's satellites. In this talk, we show a possible explanation of this dynamical feature based on the influence of the magnetic field within the thin disc. We have considered standard mass models for the luminous mass distribution, a Navarro-Frenk-White model to describe the dark halo, and we have added up the contribution to the rotation curve of a magnetic field in the disc. We have found a significant improvement of the fit in the outer part when magnetic effects are considered. Our best-fit requires a field strength of ~ 4μG which is compatible with the observations of the magnetic fields in M31.

Understanding the composition and the nature of any asteroid approaching the Earth, and consequently potentially hazardous, is a matter of general interest, both scientific and practical. The potentially hazardous asteroid 1999 RQ36 is especially accessible to spacecraft and is the primary target of NASA's OSIRIS-REx sample return mission. Spectra of this asteroid point to the most primitive meteorites (CIs and CMs) as the most likely analogs. Asteroid (3200) Phaethon is also particularly interesting. Together with 2005 UD and 2001 YB5, is one of the only 3 near-Earth asteroids with associated meteor showers, which mostly come from comets. There is evidence of the presence of hydrated minerals on its surface, usually associated with organic material. Both asteroids are classified as "B". B-type asteroids are found mostly in the middle and outer main belt and are believed to be primitive and volatile-rich. We combine dynamical and spectral information to identify the most likely main-belt origin of these two objects.