2023 Asaph

2023 Asaph, provisional designation 1952 SA, is a dark asteroid from the outer regions of the asteroid belt, approximately 21 kilometers in diameter.^[6] It was discovered on 16 September 1952, by astronomers of the Indiana Asteroid Program at Goethe Link Observatory in Indiana, United States.^[11]

2023 Asaph

Discovery[1]
Discovered by	Indiana University (Indiana Asteroid Program)
Discovery site	Goethe Link Obs.
Discovery date	16 September 1952
Designations
MPC designation	(2023) Asaph
Named after	Asaph Hall (American astronomer)[2]
Alternative designations	1952 SA
Minor planet category	main-belt · (outer)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	64.53 yr (23,571 days)
Aphelion	3.6816 AU
Perihelion	2.0703 AU
Semi-major axis	2.8760 AU
Eccentricity	0.2801
Orbital period (sidereal)	4.88 yr (1,781 days)
Mean anomaly	98.697°
Mean motion	0° 12m 7.56s / day
Inclination	22.352°
Longitude of ascending node	3.1290°
Argument of perihelion	357.53°
Physical characteristics
Dimensions	19.678±0.264 km[4][5] 20.56±0.43 km[6] 21.29±0.40 km[7] 25.44 km (calculated)[3]
Synodic rotation period	3.87±0.02 h[8][a] 4.74±0.01 h[9] 9.19±0.05 h[10]
Geometric albedo	0.057 (assumed)[3] 0.090±0.004[7] 0.096±0.018[6][5] 0.1045±0.0204[4]
Spectral type	C[3]
Absolute magnitude (H)	11.6[4][6][7] · 11.7[1][3]

Orbit and classification

Asaph orbits the Sun in the outer main-belt at a distance of 2.1–3.7 AU once every 4 years and 11 months (1,781 days). Its orbit has an eccentricity of 0.28 and an inclination of 22° with respect to the ecliptic.^[1] The asteroid's observation arc begins with its official discovery observation Goethe Link.^[11]

Physical characterization

In November 2001, a rotational lightcurve of Asaph was obtained from photometric observations by American astronomer Brian Warner. Lightcurve analysis gave a rotation period of 4.74 hours with a low brightness variation of 0.06 magnitude (U=2-).^[9] Upon re-examination of the revised data set, Warner constructed a new, ambiguous lightcurve with two possible period solutions of 3.87 and 6.28 hours (U=2-).^[8][a] These observations supersede a period of 9.19 hours derived from two fragmentary lightcurves obtained in 2001 and 2006, respectively (U=1/1).^[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, Asaph measures between 19.678 and 21.29 kilometers in diameter and its surface has an albedo between 0.09 and 0.1045.^[4][5][6][7]

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and consequently calculates a larger diameter of 25.44 kilometers based on an absolute magnitude of 11.7.^[3]

Naming

This minor planet was named in memory of American astronomer Asaph Hall (1829–1907), who discovered the Martian satellites, Phobos and Deimos.^[2] The official naming citation was published by the Minor Planet Center on 15 October 1977 (M.P.C. 4238).^[12]

Notes

1. Lightcurve plot of 2023 Asaph, Palmer Divide Observatory, Brian Warner (2001). The lightcurve is ambiguous with two possible period solutions of 6.28±0.05 and 3.87±0.02 hours.