133
Moreover, Secchi was undoubtedly a great communicator of his scientific results,
always interested in presenting and discussing his work in the widest context. For
example, total solar eclipse expeditions were an important opportunity for the international astronomical community at that time, as scientists could work together and
compare their results and thus achieve a better understanding of the nature of the
prominences and outer solar atmosphere. Secchi took part in two scientific expeditions to observe solar eclipses, in 1860 and 1870. In 1851, he had made an early
attempt to photograph the eclipsed Sun, which he repeated successfully in 1860
(Chinnici 2018). A comparison with photographs taken by other astronomers
allowed them to demonstrate that the prominences observed at the solar limb actually belong to our star.
With the eclipse of 1870, Secchi established an important scientific partnership
with Pietro Tacchini. Together they established common rules for coordinated
observations of the solar phenomena to be carried out by the members of the Società
degli Spettroscopisti Italiani (Chinnici 2008; Chinnici and Gasperini 2013).
7.6 Concluding Remarks
Thanks to his efforts to develop new methodological ideas to improve observations
and to understand the processes thus observed on the solar atmosphere, Secchi
paved the way for modern research on the processes occurring in the Sun and the
heliosphere. His legacy at the forefront of research in these fields lies in understanding the importance of having regular and uninterrupted monitoring of the solar
atmosphere and heliosphere. With improvements in the quality and quantity of data
collection, one can search for connections among the different phenomena.
Solar scientists today continue to build on the full implications of Secchi’s studies and methods. Observations made over the last two decades have shown that the
magnetic field of the Sun is the underlying cause of the many diverse phenomena
taken together under the heading of solar activity (Solanki et al. 2006). There is a
whole spectrum of magnetic features having very different sizes and properties on
the solar surface. The magnetic field in the deepest atmospheric layers is concentrated in active regions and on a network distributed over the whole Sun. In active
regions outside sunspots, the magnetic field is concentrated into more or less discrete features that together form faculae and plage regions. In outside active regions
of the quiet Sun, the magnetic flux elements form a network outlining the borders of
supergranular cells with a length scale of 20–30 Mm. Other magnetic features in the
quiet Sun are the internetwork elements, which are located in the interiors of supergranular cells. On a more localized scale, the magnetic elements forming faculae
and the network – and very likely also those in the internetwork – are located in the
downflow lanes between granules. The more we resolve ever-smaller structures in
the solar atmosphere, the more it become clearer that magnetism is an important
component of those small structures.
7 The Legacy of Angelo Secchi at the Forefront of Solar Physics Research
Moreover, Secchi was undoubtedly a great communicator of his scientific results,
always interested in presenting and discussing his work in the widest context. For
example, total solar eclipse expeditions were an important opportunity for the international astronomical community at that time, as scientists could work together and
compare their results and thus achieve a better understanding of the nature of the
prominences and outer solar atmosphere. Secchi took part in two scientific expeditions to observe solar eclipses, in 1860 and 1870. In 1851, he had made an early
attempt to photograph the eclipsed Sun, which he repeated successfully in 1860
(Chinnici 2018). A comparison with photographs taken by other astronomers
allowed them to demonstrate that the prominences observed at the solar limb actually belong to our star.
With the eclipse of 1870, Secchi established an important scientific partnership
with Pietro Tacchini. Together they established common rules for coordinated
observations of the solar phenomena to be carried out by the members of the Società
degli Spettroscopisti Italiani (Chinnici 2008; Chinnici and Gasperini 2013).
7.6 Concluding Remarks
Thanks to his efforts to develop new methodological ideas to improve observations
and to understand the processes thus observed on the solar atmosphere, Secchi
paved the way for modern research on the processes occurring in the Sun and the
heliosphere. His legacy at the forefront of research in these fields lies in understanding the importance of having regular and uninterrupted monitoring of the solar
atmosphere and heliosphere. With improvements in the quality and quantity of data
collection, one can search for connections among the different phenomena.
Solar scientists today continue to build on the full implications of Secchi’s studies and methods. Observations made over the last two decades have shown that the
magnetic field of the Sun is the underlying cause of the many diverse phenomena
taken together under the heading of solar activity (Solanki et al. 2006). There is a
whole spectrum of magnetic features having very different sizes and properties on
the solar surface. The magnetic field in the deepest atmospheric layers is concentrated in active regions and on a network distributed over the whole Sun. In active
regions outside sunspots, the magnetic field is concentrated into more or less discrete features that together form faculae and plage regions. In outside active regions
of the quiet Sun, the magnetic flux elements form a network outlining the borders of
supergranular cells with a length scale of 20–30 Mm. Other magnetic features in the
quiet Sun are the internetwork elements, which are located in the interiors of supergranular cells. On a more localized scale, the magnetic elements forming faculae
and the network – and very likely also those in the internetwork – are located in the
downflow lanes between granules. The more we resolve ever-smaller structures in
the solar atmosphere, the more it become clearer that magnetism is an important
component of those small structures.
7 The Legacy of Angelo Secchi at the Forefront of Solar Physics Research