13006 Schwaar

13006 Schwaar, provisional designation 1983 AC₁, is a stony Phocaea asteroid from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 12 January 1983, by American astronomer Brian Skiff at Lowell's Anderson Mesa Station in Flagstaff, Arizona.^[9] The asteroid was named after amateur astronomer Pierre–Yves Schwaar.^[2]

13006 Schwaar

Discovery[1]
Discovered by	B. A. Skiff
Discovery site	Anderson Mesa Stn.
Discovery date	12 January 1983
Designations
MPC designation	(13006) Schwaar
Named after	Pierre–Yves Schwaar (American amateur astronomer)[2]
Alternative designations	1983 AC1 · 1990 DH
Minor planet category	main-belt · Phocaea[3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	34.21 yr (12,495 days)
Aphelion	2.7336 AU
Perihelion	1.8143 AU
Semi-major axis	2.2739 AU
Eccentricity	0.2021
Orbital period (sidereal)	3.43 yr (1,252 days)
Mean anomaly	29.457°
Mean motion	0° 17m 14.64s / day
Inclination	28.523°
Longitude of ascending node	129.27°
Argument of perihelion	358.22°
Physical characteristics
Dimensions	5.04 km (calculated)[3] 5.325±0.052[5] 5.892±0.113 km[6]
Synodic rotation period	6.8 h[7]
Geometric albedo	0.182±0.038[5] 0.1850±0.0281[6] 0.23 (assumed)[3]
Spectral type	S[3][8]
Absolute magnitude (H)	13.6[6] · 13.7[1][3] · 13.97±0.22[8]

Orbit and classification

Schwaar is a member of the Phocaea family (701),^[4] a rather small group of asteroids with similar orbital characteristics, named after its largest member, 25 Phocaea. It orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 5 months (1,252 days). Its orbit has an eccentricity of 0.20 and an inclination of 29° with respect to the ecliptic.^[1] No precoveries were taken. The asteroid's observation arc begins 20 days after its discovery.^[9]

Physical characteristics

Schwaar has been characterized as a S-type asteroid by Pan-STARRS photometric survey.^[8]

Lightcurves

A rotational lightcurve of Schwaar was obtained from photometric observations made at the Hunters Hill Observatory (E14), Australia, and collaborating stations in December 2006. The lightcurve gave a rotation period of 6.8 hours with a brightness variation of 0.17 in magnitude (U=3-).^[7]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Schwaar measures 5.3 and 5.9 kilometers in diameter and its surface has an albedo of 0.182 and 0.185, respectively,^[6][5] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for members of the Phocaea family of 0.23, and calculates a diameter of 5.0 kilometers with an absolute magnitude of 13.7.^[3]

Naming

This minor planet was named in memory amateur astronomer Pierre–Yves Schwaar (1946–2000), member of the Saguaro Astronomy Club (SAC), telescope maker, and photographer of the night sky.^[2] The official naming citation was published by the Minor Planet Center on 9 January 2001 (M.P.C. 41939).^[10] The native Swiss amateur astronomer and immigrant to the U.S. was also an inventor and master craftsman, a model rocketeer, an USAF aircraft mechanic, a Vietnam veteran, and an eclipse chaser.