1462 Zamenhof

1462 Zamenhof, provisional designation 1938 CA, is a carbonaceous Themistian asteroid from the outer regions of the asteroid belt, approximately 27 kilometers in diameter. It was discovered on 6 February 1938, by Finnish astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory in Finland.^[12] The asteroid was named after L. L. Zamenhof, the creator of Esperanto.^[2] It is a recognized Zamenhof-Esperanto object.

1462 Zamenhof

Discovery[1]
Discovered by	Y. Väisälä
Discovery site	Turku Obs.
Discovery date	6 February 1938
Designations
MPC designation	(1462) Zamenhof
Named after	L. L. Zamenhof[2] (creator of Esperanto)
Alternative designations	1938 CA · 1963 TS 1964 VF2 · 1969 TU5
Minor planet category	main-belt · (outer) Themis[3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	53.72 yr (19,623 days)
Aphelion	3.4958 AU
Perihelion	2.8032 AU
Semi-major axis	3.1495 AU
Eccentricity	0.1100
Orbital period (sidereal)	5.59 yr (2,042 days)
Mean anomaly	7.0433°
Mean motion	0° 10m 34.68s / day
Inclination	0.9657°
Longitude of ascending node	24.810°
Argument of perihelion	187.54°
Physical characteristics
Dimensions	25.62 km (derived)[3] 25.91±0.55 km[5] 26.57±0.52 km[6] 27.366±0.166 km[7] 27.645±0.395 km[8]
Synodic rotation period	10.2±0.6 h[9] 10.4±0.1 h[10]
Geometric albedo	0.087±0.015[5] 0.0891 (derived)[3] 0.1108±0.0319[8] 0.121±0.005[6]
Spectral type	C (assumed)[3]
Absolute magnitude (H)	10.80[6][8] · 11.20[1][3][5] · 11.31±0.32[11]

Orbit and classification

Zamenhof is a Themistian asteroid that belongs to the Themis family (602),^[4] a very large family of carbonaceous asteroids, named after 24 Themis.^[13]: 23 It orbits the Sun in the outer main-belt at a distance of 2.8–3.5 AU once every 5 years and 7 months (2,042 days). Its orbit has an eccentricity of 0.11 and an inclination of 1° with respect to the ecliptic.^[1] The body's observation arc begins at the discovering observatory, one month prior to its official discovery observation.^[12]

Physical characteristics

The Lightcurve Data Base assumes Zamenhof to be a common, carbonaceous C-type asteroid,^[3] in agreement with the overall spectral type of the Themis family.^[13]: 23

Rotation period

Two rotational lightcurves of Zamenhof were obtained from photometric observations in 2006 and 2011. Lightcurve analysis gave a rotation period of 10.2 and 10.4 hours with a brightness amplitude of 0.15 and 0.30 magnitude, respectively (U=2/2).^[9][10]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Zamenhof measures between 25.91 and 27.645 kilometers in diameter and its surface has an albedo between 0.087 and 0.121.^[5][6][7][8]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0891 and a diameter of 25.62 kilometers based on an absolute magnitude of 11.2.^[3]

Naming

This minor planet was named after L. L. Zamenhof (1859–1917), a Polish-Jewish ophthalmologist and creator of Esperanto, a constructed international language.^[2] This asteroid and 1421 Esperanto are considered to be the most remote Zamenhof-Esperanto objects (a monument or a place celebrating Zamenhof). The official naming citation was published by the Minor Planet Center in January 1956 (M.P.C. 1350).^[14]