2056 Nancy

2056 Nancy, provisional designation A909 TB, is a stony background asteroid from the inner regions of the asteroid belt, approximately 10 kilometers (6 miles) in diameter. It was discovered on 15 October 1909, by German astronomer Joseph Helffrich at Heidelberg Observatory in southwest Germany.^[1] The S-type asteroid has a tentative rotation period of 15.0 hours.^[4] It was named for Nancy Marsden, wife of British astronomer Brian G. Marsden.^[2]

2056 Nancy

Discovery[1]
Discovered by	J. Helffrich
Discovery site	Heidelberg Obs.
Discovery date	15 October 1909
Designations
MPC designation	(2056) Nancy
Named after	Nancy Lou Zissell Marsden (wife of Brian G. Marsden)[2]
Alternative designations	A909 TB · 1929 VQ 1942 RA1 · 1962 XE 1972 VC1 · 1974 HL2
Minor planet category	main-belt[1][3] · (inner)[4] background[5]
Orbital characteristics[3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	108.60 yr (39,665 d)
Aphelion	2.5253 AU
Perihelion	1.9098 AU
Semi-major axis	2.2175 AU
Eccentricity	0.1388
Orbital period (sidereal)	3.30 yr (1,206 d)
Mean anomaly	303.73°
Mean motion	0° 17m 54.6s / day
Inclination	3.9361°
Longitude of ascending node	225.77°
Argument of perihelion	145.80°
Physical characteristics
Mean diameter	7.783±0.150 km[6] 8.227±0.085 km[7] 10.30 km (calculated)[4] 11.19±2.42 km[8]
Synodic rotation period	15.0 h[a]
Geometric albedo	0.16±0.08[8] 0.20 (assumed)[4] 0.3164±0.0387[7] 0.351±0.056[6]
Spectral type	SMASS = S[3][4]
Absolute magnitude (H)	12.3[1][3][4][7] 12.62[8]

Orbit and classification

Nancy is a non-family asteroid of the main belt's background population. It orbits the Sun in the inner asteroid belt at a distance of 1.9–2.5 AU once every 3 years and 4 months (1,206 days; semi-major axis of 2.22 AU). Its orbit has an eccentricity of 0.14 and an inclination of 4° with respect to the ecliptic.^[3] The asteroid's observation arc begins with its official discovery observation at Heidelberg in October 1909.^[1]

Naming

This minor planet was named after Nancy Lou Zissell Marsden, wife of British astronomer Brian G. Marsden, who established the asteroid's identification, and after whom another minor planet, 1877 Marsden, was previously named.^[2] The official naming citation was published by the Minor Planet Center on 1 April 1978 (M.P.C. 4359).^[9]

Physical characteristics

Nancy is a common S-type asteroid in the SMASS classification.^[3]

Lightcurves

As of 2018, only a single fragmentary lightcurve of Nancy has been obtained from photometric observation. Analysis of the rotational lightcurve gives a period of 15 hours with a brightness variation of 0.08 magnitude (U=1).^[4][a]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Nancy measures between 7.783 and 11.19 kilometers in diameter and its surface has an albedo between 0.16 and 0.351.^[6][7][8] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 10.30 kilometers based on an absolute magnitude of 12.3.^[4]

Notes

1. Anonymous lightcurve: rotation period 15.0 hours with a brightness amplitude of 0.08 mag. Summary figures for (2056) Nancy at Collaborative Asteroid Lightcurve Link (CALL).