1570 Brunonia

1570 Brunonia, provisional designation 1948 TX, is a stony asteroid of the Koronis family from the outer regions of the asteroid belt, approximately 12 kilometers (7.5 miles) in diameter. It was discovered on 9 October 1948, by Belgian astronomer Sylvain Arend at the Royal Observatory of Belgium in Uccle.^[1] The S-type asteroid is likely elongated and has a longer-than-average rotation period of more than 48 hours.^[7] It was named for Brown University in Rhode Island, United States.^[2]

1570 Brunonia

Discovery[1]
Discovered by	S. Arend
Discovery site	Uccle Obs.
Discovery date	9 October 1948
Designations
MPC designation	(1570) Brunonia
Named after	Brown University[2][3]
Alternative designations	1948 TX · 1952 QE1
Minor planet category	main-belt[1][4] · (outer) Koronis[5][6][7]
Orbital characteristics[4]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc	69.89 yr (25,529 d)
Aphelion	3.0028 AU
Perihelion	2.6888 AU
Semi-major axis	2.8458 AU
Eccentricity	0.0552
Orbital period (sidereal)	4.80 yr (1,754 d)
Mean anomaly	222.99°
Mean motion	0° 12m 19.08s / day
Inclination	1.6659°
Longitude of ascending node	190.05°
Argument of perihelion	226.15°
Physical characteristics
Mean diameter	10.80±1.03 km[8] 12.118±0.272 km[9][10] 12.728±0.058 km[11]
Synodic rotation period	48 h (or longer)[12]
Geometric albedo	0.166[8] 0.169±0.019[13] 0.1909[11] 0.209[9]
Spectral type	S (SDSS-MOC)[14]
Absolute magnitude (H)	11.90[9][11] 12.0[1][4][7] 12.40[8]

Orbit and classification

Brunonia is a core member of the Koronis family (605),^[5][6] a very large outer asteroid family with nearly co-planar ecliptical orbits.^[7][15] It orbits the Sun in the outer main-belt at a distance of 2.7–3.0 AU once every 4 years and 10 months (1,754 days; semi-major axis of 2.85 AU). Its orbit has an eccentricity of 0.06 and an inclination of 2° with respect to the ecliptic.^[4] The body's observation arc begins at Uccle in November 1948, one month after its official discovery observation.^[1]

Naming

This minor planet was named for Brown University in Providence, Rhode Island. The 7th oldest university in the United States, Brown was chartered in 1764.^[1] The official naming citation was published by the Minor Planet Center in February 1954 (M.P.C. 1040).^[16][3]

Physical characteristics

In the SDSS-based taxonomy, Brunonia is a common, stony S-type asteroid,^[14] which agrees with the overall spectral type for members of the Koronis family.^[15]: 23

Rotation period

In February 2016, a rotational lightcurve of Brunonia was obtained from photometric observations by the Kepler space telescope and its K2 mission (Uranus Field). Lightcurve analysis gave a rotation period of at least 48 hours with a brightness amplitude of more than 0.6 magnitude (U=n.a.), indicative of an elongated, non-spherical shape.^[7][12]

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, Brunonia measures between 10.8 and 12.7 kilometers in diameter and its surface has an albedo between 0.166 and 0.209.^{[8][9][10][11][13]} The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 and a diameter of 10.8 kilometers based on an absolute magnitude of 12.0.^[7]