3540 Protesilaos
3540 Protesilaos is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 27 October 1973, by German astronomer Freimut Börngen at the Karl Schwarzschild Observatory in Tautenburg, Germany. The assumed C-type asteroid belongs to the 50 largest Jupiter trojans and has a rotation period of 8.9 hours. It was named after the Greek hero Protesilaus from Greek mythology, the first Greek to set foot on the shores of Troy.
Orbit and classification
Protesilaos is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's Lagrangian point, 60° ahead of its orbit in a 1:1 resonance . It is also a non-family asteroid in the Jovian background population.It orbits the Sun at a distance of 4.7–5.9 AU once every 12 years and 1 month. Its orbit has an eccentricity of 0.12 and an inclination of 23° with respect to the ecliptic. A first precovery was taken at Palomar Observatory in February 1953, extending the asteroid's observation arc by 20 years prior to its official discovery observation at Tautenburg.
Physical characteristics
Protesilaos is an assumed, carbonaceous C-type asteroid, which is in line with the body's albedo , while its V–I color index of 0.94 agrees with that of most Jovian D-type asteroids.Rotation period
In March 1989 a rotational lightcurve of Protesilaos was obtained from photometric observations by astronomer Stefano Mottola at DLR Institute for Planetary Research. Lightcurve analysis gave a rotation period of 8.945 hours with a brightness amplitude of 0.13 magnitude.In October 2010, a second photometric measurement over two nights by Robert Stephens at the Goat Mountain Astronomical Research Station showed a concurring period of hours with no brightness variation given.