Star-Shy Asteroids

Thanks to Gaia, many star positions (and proper motions) and minor planet positions (orbits) have improved so much that those of us who try to observe stellar occultations by minor planets have recently seen a vast improvement in our likelihood of success. These occultation events are an excellent way to discover minor planet satellites as well as double stars. At the very least, they provide highly accurate minor planet astrometric positions that lead to more accurate orbits, and if several observers record an event, the size and shape of the minor planet can be more accurately determined.

Perhaps surprisingly, a number of low-numbered (and thus generally larger) minor planets have never been observed to occult a star. Here are the ten lowest-numbered minor planets still awaiting their first-observed stellar occultation event.

To predict future stellar occultation events for any given minor planet (and so much more!), use the latest version of Occult – Occultation Prediction Software by David Herald.

Last Updated: January 31, 2025

180 Garumna
Main-belt Asteroid. Diameter 23.440 ± 0.414 km.
Rotation Period: 23.866 hours
Discovered 1878 Jan 29 by J. Perrotin at Toulouse.
Named for the Garonne river on which the city of discovery is situated. Garumna is the ancient name.
https://en.wikipedia.org/wiki/180_Garumna

183 Istria
Main-belt Asteroid. Diameter 32.927 ± 0.168 km.
Rotation Period: 11.77 hours
Discovered 1878 Feb 8 by J. Palisa at Pola.
Named for the {now Croatian} peninsula at the northern end of the Adriatic sea, containing Trieste and the city of discovery. Named by Vice-Admiral B. Freiherr von Wüllerstorf who was the commander of the first Austrian circumnavigatory adventure with the frigate Novara.
https://en.wikipedia.org/wiki/183_Istria

228 Agathe
Main-belt Asteroid. Diameter 9.30 ± 0.8 km.
Rotation Period: 6.484 hours
Discovered 1882 Aug 19 by J. Palisa at Vienna.
Named in honor of the youngest daughter of Theodor von Oppolzer (1841-1886), professor of astronomy in Vienna.
https://en.wikipedia.org/wiki/228_Agathe

244 Sita
Main-belt Asteroid. Diameter 11.077 ± 0.022 km.
Rotation Period: 129.51 hours
Discovered 1884 Oct 14 by J. Palisa at Vienna.
Named possibly for the wife of Rama in the Sanskrit epic The Ramayana. It is a symbol of the ideal spouse and of everlasting faith.
https://en.wikipedia.org/wiki/244_Sita

262 Valda
Main-belt Asteroid. Diameter 14.645 ± 0.141 km.
Rotation Period: 17.386 hours
Discovered 1886 Nov 3 by J. Palisa at Vienna.
Any reference of this name to a person or occurrence is unknown. Name proposed by the Baroness Bettina von Rothschild.
https://en.wikipedia.org/wiki/262_Valda

263 Dresda
Main-belt Asteroid. Diameter 23.952 ± 0.213 km.
Rotation Period: 16.809 hours
Discovered 1886 Nov 3 by J. Palisa at Vienna.
The planet is named to honor the German city of Dresden.
https://en.wikipedia.org/wiki/263_Dresda

281 Lucretia
Main-belt Asteroid. Diameter 11.036 ± 0.145 km.
Rotation Period: 4.348 hours
Discovered 1888 Oct 31 by J. Palisa at Vienna.
Named in honor of Lucretia Caroline Herschel (1750-1848), sister of the discoverer (1781) of Uranus, Sir William Herschel (1738-1822), whom she assisted, beginning in 1772. She independently discovered seven or eight comets. After her brother’s death, she returned from England to Hannover, Germany and constructed a catalogue of the nebulae and clusters discovered by him. She received the Gold Medal of the Royal Astronomical Society in 1828.
https://en.wikipedia.org/wiki/281_Lucretia

291 Alice
Main-belt Asteroid. Diameter 10.456 ± 0.419 km.
Rotation Period: 4.313 hours
Discovered 1890 Apr 25 by J. Palisa at Vienna.
Name of unknown origin. Named by the Société Astronomique de France at the invitation of the discoverer. Independently discovered by A. Charlois at Nice one night later.
https://en.wikipedia.org/wiki/291_Alice

296 Phaëtusa
Main-belt Asteroid. Diameter 8.196 ± 0.100 km.
Rotation Period: 4.5385 hours
Discovered 1890 Aug 19 by A. Charlois at Nice.
Named for one of the daughters of Apollo and Klymene, changed by Zeus into poplars after the death of their brother Phaethon.
https://en.wikipedia.org/wiki/296_Pha%C3%ABtusa

299 Thora
Main-belt Asteroid. Diameter 15.757 ± 0.081 km.
Rotation Period: 272.9 hours
Discovered 1890 Oct 6 by J. Palisa at Vienna.
Named for the Norse god of thunder, weather, and crops.
Named by Geheimrat Prof. Scheibler in Berlin. In Norse mythology this name repeatedly exists as spouse of Helge, spouse of Ragnar Lodbrok, and as a girlfriend of Gudrun.
https://en.wikipedia.org/wiki/299_Thora

References
Schmadel, Lutz D. 2012. Dictionary of Minor Planet Names. 6th ed. Berlin, Germany: Springer. https://doi.org/10.1007/978-3-642-29718-2.

Solar System Dynamics. (Downloaded 31 Jan 2025). (Small-Body Database Lookup). https://ssd.jpl.nasa.gov

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