61 Danaë () is a stony ( S-type)

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

in the outer

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...

's background population, approximately 84 kilometer in diameter. It was discovered by French astronomer Hermann Goldschmidt on 9 September 1860, from his balcony in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

, France. Goldschmidt was ill when asked to name the asteroid, and requested his fellow asteroid-hunter

Robert Luther Karl Theodor Robert Luther (16 April 1822, Świdnica – 15 February 1900 Düsseldorf), normally published as Robert Luther, was a German astronomer. While working at the Bilk Observatory in Düsseldorf, Germany, he searched for asteroids and di ...

to name it instead. Luther chose to name it after

Danaë In Greek mythology, Danaë (, ; ; , ) was an Argive princess and mother of the hero Perseus by Zeus. She was credited with founding the city of Ardea in Latium during the Bronze Age. Family Danae was the daughter and only child of King Acr ...

, the mother of

Perseus In Greek mythology, Perseus (, ; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer of ...

Greek mythology Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories conc ...

. Danaë was the first asteroid to have a

diacritical A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacrit ...

character in its official name. The asteroid is orbiting the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

with a period of 5.15 years and is rotating on its axis once every 11.45 hours. In 1985, a study of

lightcurve In astronomy, a light curve is a graph (discrete mathematics), graph of the Radiance, light intensity of a celestial object or region as a function of time, typically with the magnitude (astronomy), magnitude of light received on the ''y''-axis ...

data suggested that Danaë may have a

moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

. If so, the main body would be an

ellipsoid An ellipsoid is a surface that can be obtained from a sphere by deforming it by means of directional Scaling (geometry), scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a Surface (mathemat ...

measuring , and the moon would orbit away, measuring . The density of both would be .

References

* Alberto Cellino, Renato Pannunzio, Vincenzo Zappalà, Paolo Farinella, and Paolo Paolicchi, 1985
''Do we observe light curves of binary asteroids?''
Astronomy and Astrophysics, Vol. 144, No. 2, pp. 355–362.

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Danae 000061 000061 000061 Discoveries by Hermann Goldschmidt Named minor planets 18600909