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Charting The Comets Discovered By The Observatory of the Vatican Observatory (1844-1846)

This celestial drawing titled "Graphical Representation of the Orbits of Eleven Comets Discovered by the Astronomers of the Roman College from 1844 to 1846 and Humbly Dedicated to His Holiness Pope Pius IX" presents a meticulous study of the trajectories of eleven comets discovered by the Vatican Observatory between 1844 and 1846, under the direction of the famed Astronomer Father Francesco de Vico.

These 11 observed comets include the 8 comets discovered by the Vatican Observatory, 2 of which are attributed to de Vico.   The work is possibly in the hand or de Vico or one of his collaborators, Benedetto Sestini (1840-1848), Bernardo Gambara (who made observations 7 times a day and used a comet-watch telescope), Victor della Rovere (1840-1848).   

In August 1844, De Vico sighted the first of 8 comets, which marked his first such discovery.  In 1845, De Vico discovered a comet on February 28, which M. Faye of the Paris Observatory also observed on March 6. Despite its faint appearance, this comet remained visible until April 25, four days after its closest approach to the sun. While most orbit calculations indicated a parabolic trajectory, it was ultimately determined to be a hyperbolic deviation.   

The year 1846 was particularly eventful for De Vico, who discovered four comets. The first was identified on January 24, just after its perihelion passage. It was last observed at Bonn on May 1, with orbit calculations indicating a potential elongated elliptical path with a period nearing 3000 years.

The second comet of 1846 was first seen on February 20 and independently by G. P. Bond on February 26. It passed perihelion on March 5 and was observable in Washington until May 19. Its orbit, nearly perpendicular to the ecliptic, was later defined as an elliptical path with a period of approximately 73.25 years.

De Vico discovered his third comet of 1846 on July 29, nearly a month before its closest approach to the sun and was independently spotted by Dr. Hind a couple of hours later. Observed at Bonn until August 28, this comet was small and faint throughout its visibility period.

The final comet discovery of the year occurred on September 23, with observations extending in Hamburg until October 25. Its perihelion passage was at the end of October, and while most calculations suggested a parabolic path, it was later determined as elliptical with a roughly 1382-year orbit. 

The paths of each of the 11 comets is carefully traced, centered on a brightly depicted Sun at the center, with a small model of the earth revolving around the sun and a cross at the top of the earth, perhaps suggesting the location of the Vatican Observatory.   

Text Translation and Explanation:

• a: Comet of Mauvais discovered in this observatory in the southern hemisphere.
• b: Periodic Comet of the Roman College, discovered on August 22, 1844.  This would come to be known as 54P/de Vico–Swift–NEAT.
• c: Long-period Comet discovered in the Roman College on February 25, 1845.
• d: Periodic Comet of Encke observed in the Roman College on June 10, 1846, seen only in Rome, Washington, and Philadelphia.
• e: Periodic Comet of Biela observed for comparison in the Roman College on November 24, 1845.   
• f: Long-period Comet discovered in the Roman College on January 24, 1846.
• g: Long-period Comet discovered in the Roman College on February 20, 1846. This would come to be known as 122P/de Vico.
• h: Periodic Comet of Brorsen discovered simultaneously in the Roman College on June 26, 1846.
• i: Long-period Comet of Peters discovered in the Roman College on June 26, 1846.
• k: Long-period comet towards Earth, discovered in the Roman College on June 29, 1846.
• l: Long-period comet discovered in the Roman College on September 23, 1846.
• m: Orbit of the Earth around the Sun.
• Notes below: Provide directions for the movement of each object, offering detailed observational data from specific dates.

The comet discoverers listed above are as follows:

• Victor Mauvais: Mauvais was a French astronomer and politician. He served as a student astronomer at the Observatoire de Paris from 1836 and worked at the Bureau des Longitudes from 1843 until his tragic death in 1854. He was elected to the Académie des Sciences in 1843 and won the Lalande Prize that same year for his discovery of the comet C/1843 J1. He also discovered comets C/1844 N1 and C/1847 N1.
• Johann Franz Encke: Discovered the periodic comet that bears his name in 1818. Encke calculated that it had an unusually short orbital period of 3.3 years, a significant departure from the longer periods typically associated with such celestial bodies. This comet's aphelion, positioned within Jupiter's orbit, distinguished it from others known at the time. Encke successfully predicted its return in 1822, which was observed by Carl Ludwig Christian Rümker in Australia. His accurate prediction and subsequent observations contributed profoundly to the understanding of cometary orbits and their dynamics. The specific observation related to this graphic was made on June 10, 1846. 
• Wilhelm von Biela: Identified Biela's Comet in 1826, which was observed for comparison on November 24, 1845, at the Roman College. His observations led to the understanding of cometary fragmentation. Discovered in its periodic form in 1826, the comet was first recorded in 1772 by Montaigne and Messier but not recognized as periodic until Biela's observations. The comet was observed to split into two parts during its return in 1845 (as observed by Francesco de Vico) and has not been seen since 1852. It is considered to have disintegrated, but its remnants are thought to contribute to the Andromedids meteor shower, which has shown activity in subsequent years, including a noted increase expected in 2023.  
• Theodor Brorsen: Discovered Brorsen's Comet on February 26, 1846. It was later determined that a close approach to Jupiter in 1842 had shifted the comet into its discovery orbit, highlighting the dynamic and sometimes unpredictable nature of cometary paths through the solar system.
• Christian Heinrich Friedrich Peters: Originally discovered the comet 80P/Peters-Hartley on June 26, 1846, which he initially observed while working at the Capodimonte Observatory in Naples, Italy. Despite his initial discovery, there was insufficient data to compute its orbit accurately, leading to the comet being lost to observers for over a century.

The Observatory of the Collegio Romano

This observatory is one of the oldest astronomical institutes in the world. Initially located within the Roman College of Rome, this institution reflects the Catholic Church's long-standing engagement with astronomy, primarily driven by the need to refine the calendar for liturgical purposes.

In 1582, the Gregorian calendar was promulgated by Pope Gregory XIII, based on observations made by the Jesuit mathematician Christoph Clavius and his colleagues at the Roman College. This reform was necessary to correct the drift of the calendar with respect to the equinoxes and to ensure the proper timing of Easter. The construction of the Gregorian Tower in 1580 at the college was a significant milestone, marking the beginning of formal astronomical studies under the auspices of the Church.

During the 18th century, Pope Benedict XIV established the Observatory of the Roman College in 1774, underscoring the church's enduring commitment to the science of astronomy. The observatory was later relocated to the Tower of the Winds within the Vatican in 1787-1789, directed by Msgr. Filippo Luigi Gilii. Upon Gilii's death in 1821, and due to various practical difficulties, the observatory was briefly closed.

The revival of the observatory's activities occurred in the 19th century. In 1827, the Observatory of the Capitol was established and operated until 1870. However, the political upheaval of 1870, which saw Rome captured by the Kingdom of Italy, resulted in the nationalization of the College Observatory. The observatory was then named Regio Osservatorio al Collegio Romano (Royal Observatory at the Roman College), effectively ending direct papal involvement in astronomy for a time. 

Francesco de Vico

Father Francesco de Vico (1805-1848) was appointed director of the Observatory of the Roman College in 1839. This marked the beginning of a period during which the observatory gained international acclaim.

Father de Vico's observations of Saturn's moons, Mimas and Enceladus, initially sparked skepticism, being mistaken for hallucinations due to their rarity. However, using an innovative technique that involved placing a small opaque disk within the telescope's focal plane to block out Saturn's overpowering glare, de Vico managed to confirm their orbits even with relatively modest equipment. His method allowed these satellites to be observed more consistently, demonstrating the effectiveness of his approach to peers, including some in Paris.

During his directorship, de Vico was noted for his extensive research on comets, particularly his detailed calculations regarding Halley's Comet. His predictions and charts enabled astronomers at the Roman College to be among the first to spot the comet on August 5, 1835. From 1844 to 1847, a flurry of comet discoveries occurred under his watch, with eight comets identified at the Roman College. Notably, one of these comets, boasting a 6.5-year orbit, was named after de Vico. These achievements were acknowledged with an award from the King of Denmark.

De Vico was also notable for his observations of Saturn and its rings, specifically detecting divisions in the rings that were later named the Keeler Gap. De Vico also observed the Saturnian satellites Mimas and Enceladus, determining their orbits.  His work on Venus involved trying to determine its rotation period, though without definitive success. 

Moreover, de Vico embarked on ambitious projects, such as an extensive survey aimed at cataloging stars down to the eleventh magnitude to aid in the identification of comets and new planets. Although significant progress was made, political upheaval in 1848 halted these plans. This revolutionary period targeted the Jesuits, prompting their global dispersal on the advice of Pope Pius IX. Despite an invitation to remain due to his scientific stature, de Vico chose exile, embarking on a 'triumphal journey' through Paris, London, and the United States, where he was warmly received, including by the President.

Intending to settle and continue his work in the U.S., de Vico returned to Europe briefly to recruit collaborators for the Astronomical Observatory of Georgetown College. Unfortunately, his health deteriorated rapidly, and he succumbed to an infection in London at the age of 43.