INAF - Catania Astrophysical Observatory
All daily drawings of the sunspot groups and USSPS produced by INAF - Catania Astrophysical Observatory are available in this page.
The drawings of sunspot groups and pores are maken by a Cooke refractor (150mm/2230 mm) on a 24.5 cm diameter projected image of the Sun.
This archive allows to download the USSPS and the daily drawings produced by INAF - Catania Astrophisical Observatory. Selecting year and month, it is possible to get a list of all the USSPS available for that date.
After a click on the "Search" botton the number of the found records is provided. Each record is identified by the date of observation. For each record three links appear:
- a link to view the USSPS ("View USSPS file")
- a link to download the USSPS in .txt format ("Download USSPS file")
- a link to display the jpeg2000 version of the corresponding drawing("View Sunspot drawing").
A gray bar reporting different week of the year will help to distinguish different time intervals.
Solar observations of the photosphere and chromosphere have been carried out at INAF - Catania Astrophysical Observatory (OACt) since 1876, the year of its foundation.
The program for the observations of the Sun is performed by means of an equatorial spar equipped with:
- a Cook refractor (15/2230 mm) used to make drawings of sunspot groups from visual observations;
- a 150-mm refractor (2300 mm focal length) feeding a Zeiss Hα Lyot filter (bandwidth of 2.5 or 5.0 nm) and a CCD characterized by an array size of 2200 x 2200 pixel, a pixel size of 12 x 12 micron and a digital resolution of 16 bits.