TNG

Involved people at OAB: Zitelli, Ciattaglia.

Zitelli (with Ortolani from Padova, Mancini from Napoli, and Porceddu from Cagliari) is a member of the working group ``site testing" for the Telescopio Nazionale Galileo (TNG). At present, close to the Galileo site, there are the two towers for the meteo and seeing monitoring that are routinely sending meteo and seeing data. The analysis of such data and additional experiments will allow to obtain a more complete characterization of the TNG site. Particularly important is the analysis of atmospherical dust, coming from Sahara desert, by means of a dedicated dust monitor located at the mirror level of TNG. The aim of this experiment is to compare the behaviour of dust grains of different size and to check the influence of such behaviour on astronomical seeing.

The collaboration of Zitelli and Ciattaglia with Held (Padova Obs.) on the slit drilling machine for the low dispersion spectrograph at the Galileo National Telescope has been completed. This Multi Objects Mode is an extended capability complementary to the real time built-in multislit facility and makes possible to obtain simultaneous spectroscopy of many tens of objects over a useful field of $6\times 9.5$ arcmin$^2$. The success of this MOS is demonstrated by the large number of requested nights by the astronomical community.

Zitelli is involved in a joint project with Padova, Merate, Catania and Torino observatories to implement a tunable filter (TF) at one of the instruments permanently mounted on the focal plane of TNG. This project has the necessary financial support to complete the feasibility study. The proposed etalon TF allows to obtain sequential narrow-band images spaced, if combined with Dolores, by $6-21$ Å, forming the image cube. The other main characteristics of the proposed TF combined with Dolores are: FOV of 240 arcsec (at f/11), resolving power 300-1000 and spectral range 5800-7500 Å.