Discovered by K. Reinmuth MPC designation 1131 Porzia Discovered 10 September 1929 Orbits Sun Asteroid group Mars-crosser asteroid | Discovery date 10 September 1929 Minor planet category Mars-crosser Absolute magnitude 12.9 Discoverer Karl Wilhelm Reinmuth | |
Named after Porcia Catonis
(in Shakespeare's play)
Julius Caesar Alternative names 1929 RO · 1939 TJ
1962 MB Discovery site Landessternwarte Heidelberg-Königstuhl Similar 1111 Reinmuthia, 1102 Pepita, 1056 Azalea, 132 Aethra, 218 Bianca | ||
1131 Porzia, provisional designation 1929 RO, is a stony asteroid and sizable Mars-crosser from the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 10 September 1929, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany.
In the SMASS taxonomy, Porzia is a stony S-type asteroid. It orbits the Sun at a distance of 1.6–2.9 AU once every 3 years and 4 months (1,215 days). Its orbit has an eccentricity of 0.29 and an inclination of 3° with respect to the ecliptic. The body's observation arc begins at Heidelberg, 19 days after its official discovery observation.
Two rotational lightcurves of Porzia were obtained by Vladimir Benishek at Belgrade Observatory shortly before its opposition in November 2009, and by French amateur astronomer René Roy in December 2012. Lightcurve analysis gave a well defined rotation period of 4.6584 and 4.6601 hours with a brightness variation of 0.15 and 0.19 magnitude, respectively (U=3/3). The results supersede photometric observations taken by Polish astronomer Wiesław Wiśniewski in January 1990, which rendered a lightcurve with a period 7000400000000000000♠4.0±0.2 hours and an amplitude of 0.23 magnitude (U=2).
Porzia's diameter has not been estimated by any of the prominent space-based surveys such as the Infrared Astronomical Satellite IRAS (1982), the Japanese Akari satellite (2006), NASA's Wide-field Infrared Survey Explorer (2009) and its subsequent NEOWISE mission (2013). The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 7.13 kilometers with an absolute magnitude of 13.10.
This minor planet was named after the wife of Brutus, Porcia, who kills herself at news of her husband's death in Shakespeare's play Julius Caesar. Naming citation was first published by Paul Herget in The Names of the Minor Planets in 1955 (H 106).