Group on Active Stars & Systems

Catania Astrophysical Observatory
Dipartimento di Fisica e Astronomia dell'UniversitÓ di Catania
Ricordo di Marcello Rodon˛

 La figura di Marcello Rodon˛ nella ricerca Astrofisica


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Space Projects


   click on the logo to visit the official CoRoT page    

Launched on Dec 27, 15:23 CET    -- 300 days in Orbit

Informazioni in Italiano su CoRoT e sul contributo Italiano alla missione

Multimedia information about CoRoT in Italian (Flash - html)

COROT is a space experiment (mainly supported by CNES) dedicated to ultra-high precision, wide-field, relative stellar photometry, for very long continuous observing runs on the same field of view. It has two main scientific programs working simultaneously on adjacent regions of the sky: 1) asteroseismology, and 2) search for extrasolar planets. Scientists of our group have been involved in the monitoring of the primary targets for the asteroseismology program with the 91-cm telescope of the Catania Observatory to evaluate the level of magnetic activity in these stars and their rotation periods by analyzing high-resolution spectra (R~20,000) in the region of Ca II H & K lines. In the mean time, theoretical work has been carried out by people of our group in collaboration with colleagues at the Laboratoire de Astrophysique de Marseille (France) to address the influence of stellar activity on the detection of planetary transits. Moreover a contribution to the selection of possible COROT additional programs in the field of stellar activity has been given.


 

  GAIA     click on the logo to visit the official GAIA page at ESA  

 

Gaia is an ESA mission devoted to provide a three-dimensional map of our Galaxy, the Milky Way. Gaia will provide unprecedented positional and radial velocity measurements with the accuracies needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. This amounts to about 1 per cent of the Galactic stellar population. Combined with astrophysical information for each star, provided by on-board multi-colour photometry, these data will have the precision necessary to quantify the early formation, and subsequent dynamical, chemical and star formation evolution of the Milky Way Galaxy.
Additional scientific products include detection and orbital classification of tens of thousands of extra-solar planetary systems, a comprehensive survey of objects ranging from huge numbers of minor bodies in our Solar System, through galaxies in the nearby Universe, to some 500000 distant quasars. It will also provide a number of stringent new tests of general relativity and cosmology.

The GASS team is collaborating with the GAIA RVS WG to address some specific topics that can be useful for some of the GAIA mission's tasks:

a) indicators of chromospheric activity (the Ca IR triplet):
     * NLTE synthetic Ca IRT line profiles
     * Determination of chromospheric activity level.
 b) late-type stars and spectroscopic binaries with late-type components
     *  Radial and rotational velocities: late type stars
     *  Determination of rotational velocity (vsini) of late type stars by means of:
        i) Calibration of FWHM of the Cross-correlation function;
        ii) the "spectral synthesis" method (with a grid of spectra of slowly-rotating standard stars)
     *  Spectral classification of SB2 by means of the "spectral synthesis"  method
 c) PMS binaries
     * spectral classification; activity level from Ca IRT;
     *   radial velocity curves.
 d) spectral classification:
     *   Spectral-type classification by means of "spectral synthesis" methods
 e) science alerts: flare stars, discrimination between activity-induced variability and planetary transits
 f) peculiar objects (stars with solar-like variability, flare stars, magnetic activity phenomena in close binaries.

Some of these topics would benefit from an analysis of simultaneous spectroscopic and photometric data.
The study of the stellar magnetic activity of the solar kind is useful to obtain information on stellar age that are
complementary to that derived by other methods. Moreover,stellar activity must be considered to avoid false alarms
in the case of some tasks concerning science alerts and peculiar objects. Most of the stars that GAIA will observe
shall be main sequence late-type stars and a fraction of them (at least 3-5 %) should show detectable signature of magnetic
activity in their spectra revealing them as young solar-type objects useful to study the evolution of the solar magnetic
activity in time. The study of close binaries with late-type components is also useful to get accurate masses (and radii
in the cases of eclipsing systems) in order to test stellar evolutionary models.


 

                 PLATO

                  Planetary Transits and Oscillations of Stars

click on the picture to go on the PLATO Italian web site

  

PLATO (PLAnetary Transits and Oscillations of stars) is a proposal submitted in response to the ESA Cosmic Vision 2015 - 2025 announcement of opportunity. Its objective is to detect and characterize exoplanets by means of their transit signature in front of a very large sample of bright stars, and measure the seismic oscillations of the parent stars orbited by these planets in order to understand the properties of the exoplanetary systems.

PLATO is the next-generation planet finder, building on the accomplishments of CoRoT and Kepler:

  • it will observe significantly more stars,
  • which will be three magnitudes brighter (hence the precision of the measurements will be correspondingly greater as will be those of post-detection investigations, e.g. spectroscopy, asteroseismology, and eventually imaging),
  • it will be capable of observing significantly smaller exoplanets.

People involved at INAF-OACT and Catania Univ.:
G. Cutispoto, A.F. Lanza, A.C. Lanzafame, G. Leto, S. Messina, M. Munari, I. Pagano, S. Scuderi


 click on the logo to visit the Italian WSO-UV page

 

WSO-UV is an international collaboration led by Russia (Roscosmos) to build a UV (100-310 nm) mission with capabilities which are presently, in the near and long term future unavailable to the world-wide astronomical community. The mission consists of a 1.7m telescope able to perform:

  • high resolution (R~55,000) spectroscopy by means of two echelle spectrographs covering the 100--310 nm range;

  • long slit (1 x 75 arcsec) low resolution (R~500-5000) spectroscopy;

  • deep UV and diffraction limited optical imaging.

It will be operated like a ground-based telescope, i.e. capable to perform “real time'' operations in an orbit free of visibility constraints (L2).

The imaging performance compares well with that of HST/ACS. The sensitivity of the high resolution spectrographs will exceed that of HST/STIS by a factor 10-20. In addition, WSO/UV the L2 orbit provides a significant increase in operational efficiency over low Earth orbit, and all the observing time will be available for UV astronomy. Taking all these factors into account will yield a net increase in UV productivity of a factor ~30-60, compared to HST. Furthermore, the UV-Optical capabilities of WSO/UV extend our possibilities to perform coordinated multi-wavelength campaign on selected sources, covering a spectral region, which, together with the Far/Mid-IR one, were scarcely available in the past.

The topics that can be addressed by WSO/UV concern numerous astrophysical aspects, from planetary science to cosmology.

The Italian Space Agency has included WSO/UV in its Piano Aero Spaziale Nazionale, funding the UV and optical imagers on board WSO/UV: the Field Camera Unit,(FCU).

Click here for more information on the WSO-UV Implementation in Italy


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  This site is hosted by: Istituto Nazionale di Astrofisica - Osservatorio Astrofisico di Catania I
To contact GASS: mrgrp@oact.inaf.it.
Last update: 12-10-07.