piazza del Parlamento 1, 90134 Palermo

The development of solar physics

Palermo, S. Maria delle Grazie’s church – Palazzo dei Normanni

"As soon as the large refractor was suitable for use … a first desire to be satisfied was the observation of the Sun"
(P. Tacchini, 1865)


Ileana Chinnici & Donatella Randazzo

Solar Physics developed remarkably in the second half of the nineteenth century, as a result of using
spectroscopic means for the analysis of sunlight. The works of Joseph Fraunhofer and later by
Gustav Kirchhoff, paved the way for the understanding of the physical and chemical composition of
the Sun: studying the dispersion of light through a glass prism, the dark lines observed in the
colorful spectrum were identified and turned out to be the "identity card" of the chemical elements
in the solar atmosphere.
Benefiting by a favourable climate, the Italian astronomers were assiduous observers of the Sun,
studying its photosphere and chromosphere, monitoring continuously sunspots and prominences,
searching for connections with magnetic disturbances and polar aurorae. Their research had an
international echo and were decisive for the birth of solar physics. In particular, Palermo
Observatory was renowned for solar spectroscopic studies carried out by Pietro Tacchini with a
large Merz refractor, in collaboration with Angelo Secchi in Rome.
This section illustrates the contribution given by Italian astronomy to the early development of this
discipline, and displays instruments, books and other materials witnessing the research activity in
this area in the late nineteenth and early twentieth century. All items here on display are owned by
Palermo University and kept at the Museo della Specola of INAF­Palermo Astronomical

In exhibition