When observing the comet of 1779 (C/1779 A1) which had been discovered by Bode on Jan 6 and independently by Messier on Jan 18, he observed three "nebulous stars", namely M49, M60 and M61. M49 had been discovered 8 years earlier - in 1771 - by Charles Messier, while M60 had been discovered first by Koehler (together with M59 which Oriani had missed) on April 11, then by Oriani on April 12 and by Messier on April 15, 1779. M61, on the other hand, was the original discovery of Oriani on May 5, 1779, and was seen by Messier on the same day, but taken for the comet, and recognized as a "nebula" only six days later; all these observations were made when the astronomers were following the comet.
Oriani became involved into the orbit calculation of Uranus after its discovery by William Herschel in March, 1781. After Saron, Lexell and others had shown that the object was not on a parabolic orbit and had obtained an approximate circular orbit, he calculated the planet's elliptical orbit in 1783, and published a memoir with his calculations and a table of elements for that planet in 1785. He improved this calculations for perturbations of Jupiter and Saturn in 1789. He did not accept the position as a professor of astronomy at Palermo which was offered to him consequently.
In the years following he travelled Europe and visited a number of observatories. A close friend of Piazzi, he worked with him in various astronomical projects for about 37 years, including work on the orbit of the first known asteroid, Ceres, after its discovery in 1801.
Later, Oriani participated in geodesic surveys in France and Italy. In 1802 he became cartographer for the new Italian Republic and measured the arc of meridian between Rome and Rimini. Besides continued astronomical contributions to the "Effemeridi di Milano", he published memoirs on spherical trigonometry (Memorie dell' Istituto Italiano, 1806-10) and the "Istruzione suelle misure e sui pesi" (Milan, 1831). Barnabus Oriani died at Milan on November 12, 1832.
He was honored by naming asteroid (4540) Oriani, which had been discovered at Osservatorio San Vittore in Bologna, Italy on November 6, 1988 and provisionally designated 1988 VY1; prediscovery observations had been designated 1962 XE1, 1968 DF, 1975 WL, and 1977 FH3.
Oriani gives the following discovery dates and positions:
Right Ascension Declinationas well as the description, "All three of them are very pale, and looked exactly like the comet. The observation was performed with an achromatic refractor of 5 ft [FL]. The declination of the second is about 2 or 3 minutes inacurate."
1779 April 12 188d 8' 7" +12d 45' 40" (M60) 1779 April 22 184 35 21 + 9 15 (M49) 1779 May 5 182 40 34 + 5 41 43 (M61)