1117 Reginita

1117 Reginita (prov. designation: 1927 KA) is a stony background asteroid from the inner regions of the asteroid belt. It was discovered on 24 May 1927, by Catalan astronomer Josep Comas i Solà at the Fabra Observatory in Barcelona, Spain, who named it after his niece.^[2][1] The bright S-type asteroid has a notably short rotation period of 2.9 hours and measures approximately 10 kilometers (6.2 miles) in diameter.

1117 Reginita

Shape model of Reginita from its lightcurve
Discovery[1]
Discovered by	J. Comas Solà
Discovery site	Fabra Obs.
Discovery date	24 May 1927
Designations
MPC designation	(1117) Reginita
Named after	Reginita (discoverer's niece)[2]
Alternative designations	1927 KA · A904 TA
Minor planet category	main-belt[1][3] · (inner) background[4][5]
Orbital characteristics[3]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	112.47 yr (41,080 days)
Aphelion	2.6934 AU
Perihelion	1.8017 AU
Semi-major axis	2.2475 AU
Eccentricity	0.1984
Orbital period (sidereal)	3.37 yr (1,231 days)
Mean anomaly	245.71°
Mean motion	0° 17m 33s / day
Inclination	4.3446°
Longitude of ascending node	147.14°
Argument of perihelion	151.05°
Physical characteristics
Dimensions	9.82±2.35 km[6] 10.193±0.250 km[7][8] 10.29 km (taken)[9] 10.292 km[10] 11.22±0.35 km[11]
Synodic rotation period	2.928±0.0134 h[12] 2.94±0.010 h[13] 2.9458±0.0002 h[14] 2.946±0.001 h[15] 2.9463±0.0006 h[16] 2.9464±0.0005 h[17]
Geometric albedo	0.293±0.041[11] 0.3516[10] 0.3585±0.0785[8] 0.36±0.13[6]
Spectral type	S (Tholen)[9]
Absolute magnitude (H)	11.7[1][3][11]

Orbit and classification

Reginita is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.^[4][5] It orbits the Sun in the inner asteroid belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,231 days; semi-major axis of 2.25 AU). Its orbit has an eccentricity of 0.20 and an inclination of 4° with respect to the ecliptic.^[3] The asteroid was first observed as A904 TA at Heidelberg Observatory in October 1904. The body's observation arc also begins at Heidelberg in April 1930, almost three years after its official discovery observation at Barcelona.^[1]

Naming

This minor planet was named after the niece of the discoverer. The naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 105).^[2]

Physical characteristics

In the Tholen classification, Reginita is a common, stony S-type asteroid.^[9]

Rotation period

Several rotational lightcurves of Reginita have been obtained from photometric observations since 1988.^{[12][13][14][15][16][17]} The consolidated lightcurve analysis gave a rotation period of 2.946 hours with a brightness amplitude between 0.10 and 0.33 magnitude (U=3).^[9]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Reginita measures between 9.82 and 11.22 kilometers in diameter and its surface has an albedo between 0.293 and 0.36.^{[6][7][8][10][11]} The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE data, that is, an albedo of 0.3516 and a diameter of 10.29 kilometers based on an absolute magnitude of 11.69.^[9][10]