Thanks to Fredi De Maria of the ORSA, Palermo, Italy, Hodierna's book "De Admirandis Coeli Characteribus", which contains his observations of nebulous objects, can now be found online (Italian language website). The book and the images were made available by the Osservatorio Astronomico di Palermo. The present author is grateful to Fredi for mailing him a copy of the article by Serio et.al.. This allowed me to revise this page appropriately.
Hodierna classified his objects according to what he thought they were resolvable into stars; he believed that all nebulous objects were actually cluster, which was a common view at that time, since Galilei had resolved the Milky Way, and e.g. the Praesepe cluster M44. The scheme was:
Hodierna's observations include an independent rediscovery of the Andromeda Nebula (M31) and the Orion Nebula (M42), and at least 9 (probably 10) own true discoveries, as listed by Kenneth Glyn Jones: M6, the Lagoon Nebula M8, M36, M37, M38, M41, M47, NGC 2362, NGC 6231, and (possibly) NGC 2451. Hodierna was also the first who made a still preserved drawing of the Orion Nebula M42.
A list of the objects described by Hodierna follows. It was taken from Serio's original article, corrected for the misprint of NGC 2445 for NGC 2451, and contains several more objects not given above: It lists an original rediscovery of Brocchi's Cluster, an original "discovery" or first description of the Alpha Persei Moving Cluster, the probable original discoveries of M34, M33, and NGC 752, as well as possible original discoveries of NGC 2169 and NGC 2175.
Ha. I.1 M45 (Pleiades) Ha. I.2 Hyades (Mel 25) Ha. I.3 Coma Berenices Star Cluster, Mel 111 Ha. I.4 ! Alpha Persei Moving Cluster, Mel 20 Ha. I.5 (!) M42 Ha. I.6 Asterism including Lambda, Phi1 and Phi2 Orionis Ha. I.7 ! NGC 6231 Ha. I.8 Asterism in "the Water of" Aquarius
Ha. II.1 M44 (Praesepe) Ha. II.2 M7 Ha. II.3 NGC 869/884, h and Chi Persei Ha. II.4 ! M6 Ha. II.5 Asterism of Nu1, Nu2 Sagittarii Ha. II.6 ! M8 (Lagoon Nebula) Ha. II.7 ! M36 Ha. II.7 ! M37 Ha. II.7 ! M38 Ha. II.8 (!) "Al Sufi's Nebula", Brocchi's Cluster, Collinder 399 Ha. II.9 Asterism around 88 Herculis Ha. II.10 Asterism in front of the head of Capricornus
Ha. III.1 Asterism in Coma Berenicis Ha. III.2 Asterism in Coma Berenicis Ha. III.3 (!) M31
Ha. IV.1 ! M47 Ha. IV.2 ! M41 Ha. IV.3 asterism including Nu1, Nu2, Pi Puppis Ha. IV.4 !? probably M33 Ha. IV.4 !? probably NGC 752 Ha. IV.5 ? insufficient description Ha. IV.6 ? insufficient description Ha. IV.7 ? insufficient description Ha. IV.8 non-existent nebulosity near Hyades Ha. IV.9 non-existent nebulosity near Pleiades Ha. IV.10 !?? NGC 2169 ? Ha. IV.11 !?? NGC 2175 ? Ha. IV.12 !? probably M34Occultae
Ha. IV.13 ? insufficient description Ha. IV.14 ? insufficient description Ha. IV.15 ? insufficient description
Ha. V.1 ! NGC 2362 Ha. V.2 !? NGC 2451 ? (misprinted 2445 in Serio's article) Ha. V.3 Asterism including k1, k2 Velorum (near NGC 2671) Ha. V.4 Asterism in Canis Maior including star HD 58535
Please send me pointers to any errors, clarifications and/or comments, as well as any further info you have.
Last Modification: August 25, 2007