astro.wikisort.org - Asteroid

725 Amanda (prov. designation: A911 UQ or 1911 ND) is a dark background asteroid, approximately 22 kilometers (14 miles) in diameter, that is located in the central regions of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 21 October 1911.[1] The carbonaceous C-type asteroid (CSU/C0) has a short rotation period of 3.7 hours. It was named after Amanda Schorr, wife of German astronomer Richard Schorr (1867–1951).[3]

725 Amanda

Modelled shape of Amanda from its lightcurve
Discovery [1]
Discovered by	J. Palisa
Discovery site	Vienna Obs.
Discovery date	21 October 1911
Designations
MPC designation	(725) Amanda
Pronunciation	German: [aːˈmandaː][2]
Named after	Amanda Schorr, wife of Richard Schorr (1867–1951) (German astronomer)[3]
Alternative designations	A911 UQ · 2016 FH6 1911 ND
Minor planet category	main-belt [1][4] · (middle) background [5][6][7]
Orbital characteristics [4]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc	104.58 yr (38,198 d)
Aphelion	3.1422 AU
Perihelion	2.0022 AU
Semi-major axis	2.5722 AU
Eccentricity	0.2216
Orbital period (sidereal)	4.13 yr (1,507 d)
Mean anomaly	114.51°
Mean motion	0° 14m 20.04s / day
Inclination	3.7902°
Longitude of ascending node	68.679°
Argument of perihelion	323.36°
Physical characteristics
Mean diameter	20.49±0.28 km[8] 21.51±2.2 km[9] 23.687±0.215 km[10][11]
Synodic rotation period	3.749 h[12]
Pole ecliptic latitude	(145.0°, −63.0°) (λ1/β1)[6] (320.0°, −70.0°) (λ2/β2)[6]
Geometric albedo	0.068±0.015[10][11] 0.0721±0.017[9] 0.082±0.003[8]
Spectral type	Tholen = CSU [4] C0 (Barucci) B–V = 0.738±0.046[4] U–B = 0.417±0.070[4]
Absolute magnitude (H)	11.66[10][12] 11.80[1][4] 11.81[8][9]

Orbit and classification

Amanda is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[5][6][7] It orbits the Sun in the central asteroid belt at a distance of 2.0–3.1 AU once every 4 years and 2 months (1,507 days; semi-major axis of 2.57 AU). Its orbit has an eccentricity of 0.22 and an inclination of 4° with respect to the ecliptic.[4] The body's observation arc begins at Vienna Observatory on 29 September 1915, almost four years after its official discovery observation.[1]

Naming

This minor planet was named after Amanda Schorr, wife of Richard Schorr (1867–1951), a German astronomer at Bergedorf Observatory, after whom asteroid 1235 Schorria and lunar crater Schorr were named. The asteroid's name was proposed by Palisa in 1913, on the occasion of the 24th meeting of the Astronomische Gesellschaft in Hamburg, Germany (AN 196, 139).[3] The naming was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 73).[3]

Physical characteristics

In the Tholen classification, Amanda's spectral type is closest to that of a carbonaceous C-type asteroid, yet also somewhat similar to a stony S-type with an "unusual" spectrum (CSU).[4] In the taxonomy by Barucci (1987), the asteroid is a dark C-type (C0).[6]

Rotation period and poles

A rotational lightcurve of Amanda was obtained from photometric observations by European astronomers at the La Silla Observatory before 1995. Lightcurve analysis gave a well-defined rotation period of 3.749 hours with a brightness variation of 0.35 magnitude (U=3).[12]

In October 2010, French amateur astronomer Maurice Audejean (B92) determined a concurring period of (3.7431±0.0003) hours with an amplitude of (0.42±0.01) magnitude (U=3),[13] while in August 2018, a further observation by the TESS-team reported a period of (3.74301±0.00005) hours and an amplitude of (0.27±0.05) magnitude (U=2).[14]

In 2016, a modeled lightcurve gave a sidereal period of 3.74311±0.00002 hours using data from the Uppsala Asteroid Photometric Catalogue, the Palomar Transient Factory survey, and individual observers, as well as sparse-in-time photometry from the NOFS, the Catalina Sky Survey, and the La Palma surveys (950). The study also determined two spin axes of (145.0°, −63.0°) and (320.0°, −70.0°) in ecliptic coordinates (λ, β).[15]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Amanda measures (20.49±0.28), (21.51±2.2) and (23.687±0.215) in diameter and its surface has an albedo of (0.082±0.003), (0.0721±0.017) and (0.068±0.015), respectively.[8][9][10][11]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0824 and calculates a diameter of 21.56 kilometers based on an absolute magnitude of 11.66.[16] Alternative mean-diameters published by the WISE team include (19.53±6.07 km), (21.68±6.40 km), (23.286±0.149 km) and (30.73±4.85 km) with a corresponding albedo of (0.08±0.04), (0.055±0.037), (0.0509±0.0052) and (0.03±0.03).[6][16]

References

External links

• Lightcurve Database Query (LCDB), at www.minorplanet.info
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 725 Amanda at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 725 Amanda at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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[de] (725) Amanda

(725) Amanda ist ein Asteroid des Hauptgürtels, der am 21. Oktober 1911 vom österreichischen Astronomen Johann Palisa in Wien entdeckt wurde.

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- [en] 725 Amanda

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[es] (725) Amanda

(725) Amanda es un asteroide perteneciente al cinturón de asteroides descubierto el 21 de octubre de 1911 por Johann Palisa desde el observatorio de Viena, Austria. Está nombrado en honor de la esposa del astrónomo alemán Richard Schorr (1867-1951).[2]

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[ru] (725) Аманда

(725) Аманда (нем. Amanda) — астероид главного пояса, который был открыт 21 октября 1911 года австрийским астрономом Иоганном Пализой в Венской обсерватории и назван в честь жены немецкого астронома Рихарда Шорра — Аманды[1].

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