Calendar

I will present results from my recent papers based on XMM-Newton observations of young stars in Star Forming Regions near Orion A (Kappa Ori) and Rho Ophiuchi. These observations were aimed at discovering new young stars and infer their ages, their distances and the relationship with the parent cloud. In Kappa Ori, with 40 ks of XMM/EPIC we have derived X-ray fluxes and luminosities of about 120 young stars with and without disks near Kappa Ori (B0 type). X-ray luminosity functions provided a “yardstick” to infer that these stars form a separate cluster centered on Kappa Ori (~250 pc), much closer than ONC (~410 pc) and unrelated to it. In Rho Ophiuchi, with 50+140 ks we have discovered a group of disk-less stars around Rho Oph itself and significantly older (5-10 Myr) than the bulk of YSOs (1 Myr) in the main core of the cloud, L1688. As an unexpected discovery, Rho Oph itself is a periodic emitter of hard X-rays, mimicking a “X-ray lighthouse”, and hinting that either a strong magnetism or an unseen companion are the source of such X-rays.

Space missions are very complex projects with peculiar characteristics such as: strategic importance, extent of international participation, specialized industrial sector, high investment costs, long-term program duration, impossibility of intervening in space for repairs and/or maintenance. These peculiarities strongly influence the realization process since its conception. This talk provides an introduction to methods and tools of project management of a space mission under the guidance of the European Space Agency. The following topics will be covered: General section: – Introduction to management of complex projects; – Key elements for the design of a space mission; – Main phases for the development of a space mission; – The life cycle of ESA programs; – The European Cooperation for Space Standardization (ECSS) documentation for project management and quality control. Phase A study: – Objectives of a phase A; – The main activities of analysis and development; – Preliminary Requirements Review (PRR) documentation.

High resolution spectroscopy, providing constraints on plasma motions and temperatures, is a powerful means to investigate the structure of accretion streams in Classical T Tauri stars (CTTS). In particular the accretion-shock region, where the accreting material is heated to temperatures of a few million degrees, can be probed by X-ray spectroscopy. MHD models predict that this hot post-shock plasma should have an inward bulk motion, with v_post ~ 100 km/s, with respect to the surrounding stellar atmosphere. To verify this prediction we searched for a Doppler shift in the deep Chandra/HETG observation of the CTTS TW Hya, perfectly suited for this task because of the excellent S/N and spectral resolution of the dataset, and because of the ideal target inclination. This test should allow us to constrain definitively the nature of this X-ray emitting plasma component in CTTS, and infer constraints on the accretion stream geometry. We searched for a Doppler shift in the X-ray emission from TW Hya by measuring the position of a selected sample of emission lines. To check the absolute wavelength calibration of the Chandra gratings, and to check whether or not bulk motions with respect to the photosphere are observed in coronal plasma, we also analyzed a sample of Chandra/HETG spectra of non-accreting active stars. We found that the soft part of the X-ray spectrum of TW Hya is significantly red-shifted by ~40 km/s with respect to the known radial velocity of the stellar photosphere. Conversely no X-ray redshift is observed in the X-ray emission of non-accreting active stars. The evidence that the X-ray emitting plasma on TW Hya is moving inward with respect to the stellar surface definitively confirms that it originates in the post-shock region, at the base of the accretion stream, and not in coronal structures. The observed radial velocity indicates that the base of the accretion stream on TW Hya is located at low latitudes on the stellar surface. Moreover the observed velocity of the soft X-ray emitting plasma is very similar to the velocity of the narrow component of the CIV resonance doublet at 1550 A, suggesting that they both originate from the same post-shock regions, that the hypothesis of free-fall regime in the accretion streams holds, and that complex magnetic field geometries, as that of TW Hya, allow low latitude accretion spots.

The Carte du Ciel project is considered the mother of all astrometric enterprises. It was conceived at the end of 19th century and was aimed at photographing the entire sky vault, to produce a catalogue of stars up to magnitude 11 and a chart containing stars up to magnitude 14.. This international endeavour was promoted by Paris Observatory in 1887: 18 observatories from both hemispheres participated in it, more or less successfully. This talk will illustrate how the project was originated and developed, why it remained partially inachieved and what was its impact on the astrometric missions which preceded the current GAIA mission.

Star-Planet Interaction (SPI) is a broad phenomenological term which encompasses a variety of physical effects relevant for the evolution of extra-solar planetary systems, in particular for those hosting giant gas planets in close orbits around their parent star. While theoretical expectations of SPI are abundant, observational signatures are still elusive with current instrumentation and adopted observing strategies. I will review the state of the art on the matter, and possible future developments that may help us for a better characterization of exoplanets and their abitability conditions.