Instruments

Solar observations of the photosphere and chromosphere have been carried out at the Catania Astrophysical Observatory (OACt) since 1880, the year of its foundation. The observations are carried out at the INAF - Catania Astrophysical Observatory by means of an equatorial spar.

The equatorial spar is equipped with:

• a 150-mm Cook refractor (2230 mm focal length);
• a 150-mm refractor (2300mm focal length) feeding a Zeiss Halpha Lyot filter (bandwidth of 0.25 or 0.50 Å, tunable filter range ±1 Å) and a sCMOS camera Andor Marana with a sensor of 2048 x 2048 pixels, a pixel size of 11 micron and a dynamical range of 16 bit;
• a 150-mm refractor (2300mm focal length) feeding an Halpha Halle Lyot filter.

The program performed by means of these instruments includes: daily drawing of sunspots and pores by projection of the Sun image; digital image acquisitions (every 15 min) in the Halpha line center (6562.8 Å) and wings, besides than monitoring of transient phenomena, like flares and active prominences. The photospheric and chromospheric data acquired at the INAF-OACt are distributed to international Solar Data Centers, like the SIDC in Brussels. The fits photospheric images are used and published in the Debrecen Photoheliographic Data (DPD) sunspot catalogue. The fits chromospheric images are daily provided to the Global High Resolution Halpha Network.