328
19.3 The Observatory at Campidoglio
In 1303 Pope Boniface VIII (1294–1303) established the University of Rome
Studium Urbis that would later become La Sapienza. Since its founding, the
University of Rome has hosted mathematicians and astronomers, but, unlike the
Collegio Romano, it did not have any observatory to support astronomical studies.
In 1824, by the Papal Edict Quod Divina Sapientia, Pope Leo XII (1823–1829)
funded the Astronomical Observatory of La Sapienza and decreed that it should be
directed by the full professor in astronomy at this University. The first director of the
observatory was Feliciano Scarpellini (former director of Specola Caetani). In
1827, he obtained a tower on the roof of Campidoglio from Cardinal Zelada and
equipped it with a meridian and many other scientific instruments. Scarpellini was
mainly devoted to study celestial mechanics as applied to stars, planets, and minor
bodies of the solar system. In his scientific activity, he was supported by his niece,
Caterina Scarpellini (1808–1873), whose brilliance as a scientist can be seen in that
she was one of the very first Italian women to belong to scientific academies in Italy
and abroad.
In 1840, Ignazio Calandrelli (1792–1866), nephew of Giuseppe Calandrelli, succeeded Scarpellini as director of the observatory. But due to political pressures
against the location of the observatory (in the Palazzo Senatorio in Campidoglio,
close to the seat of the city government), in 1842 he moved to Bologna and took
over as director of the local observatory. When Pius IX came back to Rome in 1849,
he asked Calandrelli to come back and restart observations at Campidoglio (Secchi
1877) and provided him with a new Ertel meridian circle (Fig. 19.3) (Calandrelli
1852). In 1860 Calandrelli was able to equip the observatory with a new Merz telescope (4.5″ aperture) with an equatorial mounting.
He retired in 1865 and was succeeded as director of the observatory by Lorenzo
Respighi (1824–1889), former director of Bologna Observatory, which he had left
for political reasons as Bologna had just become part of the new Kingdom of Italy.
Respighi immediately invited three bright young collaborators to serve at the observatory: Alfonso Di Legge (1847–1938), Francesco Giacomelli (1849–1936), and
Antonio Prosperi (1841–1921).
Respighi was an excellent scientist and among the first to appreciate the enormous potential of spectroscopy as applied to astronomy. He asked Merz to build a
large prism with a 12° refracting angle (Fig. 19.6) and used it to obtain stellar spectra, spectra of solar flares, and spectra of sunspots (Respighi 1869). He was the first
to understand that the characteristic scintillation observed in stars is due to atmospheric dispersion of starlight (Respighi 1868). From 1869 to 1895, Respighi and
his collaborators systematically observed the Sun, regularly measuring its diameter
and reporting on the evolution of solar flares.
After the arrival of the Kingdom of Italy in 1870, the Campidoglio Observatory
remained in operation, and Respighi was allowed to maintain his status as professor
and director of the observatory. Another important project started by Respighi at
Campidoglio was the completion of a huge star catalog based on more than 80,000
L. A. Antonelli
19.3 The Observatory at Campidoglio
In 1303 Pope Boniface VIII (1294–1303) established the University of Rome
Studium Urbis that would later become La Sapienza. Since its founding, the
University of Rome has hosted mathematicians and astronomers, but, unlike the
Collegio Romano, it did not have any observatory to support astronomical studies.
In 1824, by the Papal Edict Quod Divina Sapientia, Pope Leo XII (1823–1829)
funded the Astronomical Observatory of La Sapienza and decreed that it should be
directed by the full professor in astronomy at this University. The first director of the
observatory was Feliciano Scarpellini (former director of Specola Caetani). In
1827, he obtained a tower on the roof of Campidoglio from Cardinal Zelada and
equipped it with a meridian and many other scientific instruments. Scarpellini was
mainly devoted to study celestial mechanics as applied to stars, planets, and minor
bodies of the solar system. In his scientific activity, he was supported by his niece,
Caterina Scarpellini (1808–1873), whose brilliance as a scientist can be seen in that
she was one of the very first Italian women to belong to scientific academies in Italy
and abroad.
In 1840, Ignazio Calandrelli (1792–1866), nephew of Giuseppe Calandrelli, succeeded Scarpellini as director of the observatory. But due to political pressures
against the location of the observatory (in the Palazzo Senatorio in Campidoglio,
close to the seat of the city government), in 1842 he moved to Bologna and took
over as director of the local observatory. When Pius IX came back to Rome in 1849,
he asked Calandrelli to come back and restart observations at Campidoglio (Secchi
1877) and provided him with a new Ertel meridian circle (Fig. 19.3) (Calandrelli
1852). In 1860 Calandrelli was able to equip the observatory with a new Merz telescope (4.5″ aperture) with an equatorial mounting.
He retired in 1865 and was succeeded as director of the observatory by Lorenzo
Respighi (1824–1889), former director of Bologna Observatory, which he had left
for political reasons as Bologna had just become part of the new Kingdom of Italy.
Respighi immediately invited three bright young collaborators to serve at the observatory: Alfonso Di Legge (1847–1938), Francesco Giacomelli (1849–1936), and
Antonio Prosperi (1841–1921).
Respighi was an excellent scientist and among the first to appreciate the enormous potential of spectroscopy as applied to astronomy. He asked Merz to build a
large prism with a 12° refracting angle (Fig. 19.6) and used it to obtain stellar spectra, spectra of solar flares, and spectra of sunspots (Respighi 1869). He was the first
to understand that the characteristic scintillation observed in stars is due to atmospheric dispersion of starlight (Respighi 1868). From 1869 to 1895, Respighi and
his collaborators systematically observed the Sun, regularly measuring its diameter
and reporting on the evolution of solar flares.
After the arrival of the Kingdom of Italy in 1870, the Campidoglio Observatory
remained in operation, and Respighi was allowed to maintain his status as professor
and director of the observatory. Another important project started by Respighi at
Campidoglio was the completion of a huge star catalog based on more than 80,000
L. A. Antonelli