2542 Calpurnia, provisionally designated 1980 CF, is a carbonaceous high-albedo asteroid from the outer regions of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 11 February 1980, by American astronomer Edward Bowell at Anderson Mesa Station, Flagstaff, United States. The asteroid was named after Julius Caesar's wife,  Calpurnia.
Orbit and classification
Calpurnia orbits the Sun in the outer main-belt at a distance of 2.9–3.4 AU once every 5 years and 6 months (2,024 days). Its orbit has an eccentricity of 0.07 and an inclination of 5 ° with respect to the ecliptic. In 1954, a first  precovery was taken at the Palomar Observatory in California, extending the body's observation arc by 26 prior to its official discovery observation at Anderson Mesa.
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite
IRAS and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Calpurnia measures 27.6 and 20.854 kilometers in diameter, and its surface has an albedo of 0.0639 and 0.102, respectively.  It has an  absolute magnitude of 11.6.
Near-infrared spectroscopic observations, however, gave a higher albedo of 0.15 with a subsequently shorter diameter of 18 kilometers.
Calpurnia has a featureless surface with up to 60% amorphous magnesium pyroxenes that might explain the high albedo for an carbonaceous outer-belt asteroid.
As of 2017, no rotational
lightcurve has been obtained. The body's spectral type, as well as its rotation period and shape remain unknown. 
minor planet was named after Calpurnia, the last wife of Julius Caesar. The approved naming citation was published by the  Minor Planet Center on 8 April 1982 ( ). M.P.C. 6834
^ a b c d e f
"JPL Small-Body Database Browser: 2542 Calpurnia (1980 CF)" (2017-01-27 last obs.). Jet Propulsion Laboratory . Retrieved . 18 June 2017
^ a b c
Schmadel, Lutz D. (2007). "(2542) Calpurnia". Dictionary of Minor Planet Names – (2542) Calpurnia. Springer Berlin Heidelberg. p. 208. doi: 10.1007/978-3-540-29925-7_2543. ISBN . 978-3-540-00238-3
^ a b c
Kasuga, Toshihiro; Usui, Fumihiko; Shirahata, Mai; Kuroda, Daisuke; Ootsubo, Takafumi; Okamura, Natsuko; et al. (February 2015). "Near-Infrared Spectra of High-Albedo Outer Main-Belt Asteroids". The Astronomical Journal. 149 (2): 8. Bibcode: 2015AJ....149...37K. doi: 10.1088/0004-6256/149/2/37. 37.
^ a b c
Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv: . 1109.4096 Bibcode: 2011ApJ...741...68M. doi: 10.1088/0004-637X/741/2/68 . Retrieved . 18 June 2017
^ a b c
Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode: 2004PDSS...12.....T . Retrieved . 22 October 2019
Hasselmann, P. H.; Carvano, J. M.; Lazzaro, D.; Mothé-Diniz, T. (February 2010). "SDSS-based taxonomic classification and orbital distribution of main belt asteroids". Astronomy and Astrophysics. 510: 12. Bibcode: 2010A&A...510A..43C. doi: 10.1051/0004-6361/200913322 . Retrieved . 8 August 2017
^ a b
"2542 Calpurnia (1980 CF)". Minor Planet Center . Retrieved . 18 June 2017
"LCDB Data for (2542) Calpurnia". Asteroid Lightcurve Database (LCDB) . Retrieved . 18 June 2017
"MPC/MPO/MPS Archive". Minor Planet Center . Retrieved . 18 June 2017