88 Thisbe

Thisbe, minor planet designation 88 Thisbe, is the 13th largest main-belt asteroid. It was discovered by C. H. F. Peters on June 15, 1866, and named after Thisbe, heroine of a Roman fable. This asteroid is orbiting the Sun at a distance of 414.025 Gm with a period of 1681.709 days and an orbital eccentricity (ovalness) of 0.165. The orbital plane is inclined at an angle of 5.219° to the ecliptic.

On October 7, 1981, asteroid 88 Thisbe was observed to occult the 9th-magnitude star SAO 187124 from 12 sites. The timing of the different chords across the asteroid provided a diameter estimate of $0.81$. This is 10% larger than the diameter estimate based on radiometric techniques. During 2000, 88 Thisbe was observed by radar from the Arecibo Observatory. The return signal matched an effective diameter of 207 ± 22 km. This is consistent with the asteroid dimensions computed through other means.

Photometric observations of this asteroid during 1977 gave a light curve with a period of 6.0422 ± 0.006 hours and a brightness variation of 0.19 in magnitude.

Perturbation
Thisbe has been perturbed by asteroid 7 Iris and in 2001 Michalak estimated it to have a mass of 15 kg. But Iris is strongly perturbed by many minor planets such as 10 Hygiea and 15 Eunomia.

In 2008, Baer estimated Thisbe to have a mass of 10.5 kg. In 2011 Baer revised this to 18.3 kg with an uncertainty of 1.1 kg.