Skip to main content
SearchLoginLogin or Signup

Paolo Maffei (1926–2009)

Maffei was one of the pioneers of infrared astronomy research; in 1968 he discovered two highly obscured galaxies that are now known as members of “Maffei’s Group of Galaxies”.

Published onDec 12, 2022
Paolo Maffei (1926–2009)

Photo credit: Wikipedia.

Infrared astronomer and popularizer of astronomy Paolo Maffei passed beyond the plane of our galaxy on Sunday March 1, 2009, at the age of 83.

Born January 2, 1926 in Arezzo, Italy, Paolo Maffei grew up in Foligno, in the Province of Perugia. Maffei reflected in an autobiographical conference presentation that “the study of the celestial bodies at infrared wavelengths was almost a pre-destination” ([1], p. 19). At the University of Florence Maffei’s thesis work through the Observatory of Arcetri focused on an improved classification criteria for cool late-type stars via spectral analysis, under the mentorship of Attilio Colacevich and Giorgio Abetti. Post-graduation, Maffei focused on solar physics as a volunteer assistant at the observatory.

In 1955 Maffei joined Bologna University, utilizing the Zeiss 60-cm reflector of Loiano Station to photograph globular clusters, nebulae, comets, and galaxy clusters (searching for supernovae). It was here that he developed a special life-long fascination for comets (especially as probes of the solar wind), star-forming regions, and pre-main sequence objects ([1], p. 20). In response to the initial releases from the Palomar Sky Survey, Maffei set out to produce an atlas-catalogue of merging galaxies based on photographs obtained at Loiano. However, at a 1958 IAU meeting he discovered that a similar project was already well-underway by Vorontsov Velyamoniv, so the project was cut short and his observations of nine peculiar galaxies were published in 1960 [2].

Maffei moved to the Asiago Astrophysical Observatory of the University of Padua in 1959 and in 1961 utilized the Schmidt 80/120 cm telescope of the Hamburg Observatory in Germany to obtain large field spectra of star-forming regions. He returned to his native Italy in 1963, in the position of assistant professor of astrophysics at the University of Rome, where he earned the post-laureate degree of Libera Docenza in 1967. Maffei was appointed the Director of the Astrophysical Observatory in Catania in 1976, and in 1980 made his final professional move, to the Physics Department at the University of Perugia with the rank of Full Professor of Astrophysics, where he directed the construction of an automated observatory. In retirement he was honored with the title of Professor Emeritus in 2002, shortly after a national conference in infrared astronomy was held in his honor.

By pushing the technology of infrared photography, Maffei discovered numerous long period (Mira) variables (LPVs). As cooler LPV tended to have longer periods, Maffei dedicated decades of his life to monitoring the behavior of this population of stars. Maffei’s standard technique was to photograph a particular starfield in both blue light and infrared; cooler red stars would appear brighter on the latter than the former. But on a set of plates taken on September 29, 1967 Maffei found a peculiar object in Cassiopeia, within the plane of the Milky Way in the so-called Zone of Avoidance where galactic dust obscures extragalactic objects. The object, now called Maffei 1, appeared “compact and elliptical” in the infrared but was invisible in blue light [3]. Maffei reflected that while he was preparing to publish his observations of the object “I found the second object, and at first I was a bit annoyed. Two new and extraordinary objects was beginning to be too many!” ([1], p. 24). Maffei 1 and Maffei 2, now known to be a large elliptical and intermediate class spiral galaxy, respectively, are the two largest members of the Maffei Group of nine known galaxies, one of the closest galactic groups to our Local Group [4].

Maffei is also known for his popularizations of astronomy, written in his native Italian (some enjoying multiple editions), with the majority subsequently translated into other languages (including English). These works include Al di là della Luna [Beyond the Moon] (1973), I mostri del cielo [Monsters in the Sky] (1976), L'universo nel tempo [The Universe in Time] (1982) La cometa di Halley: dal passato al presente [Halley’s Comet: From Past to Present] (1984), and Giuseppe Settele, il suo diario e la questione galileiana [Giuseppe Settele, his Diary and the Galilean Question] (1987).

A member of several IAU Divisions and Commissions, including Variable Stars (V) and Planetary Science (III) until his death, Maffei was also a member of numerous astronomical organizations, including the AAS, Astronomical Society of the Pacific, British Astronomical Association, Royal Astronomical Society, and Società Astronomica Italiano. Asteroid 18426 Maffei (discovered 1993) is named in his honor.

Additional References:

No comments here