6042 Cheshirecat

6042 Cheshirecat (/ˈtʃɛʃərkæt/ or /ˈtʃɛʃɪərkæt/), provisional designation 1990 WW₂, is an eccentric, rare-type asteroid and large Mars-crosser from the outer regions of the asteroid belt, approximately 14 kilometers in diameter. It was discovered by Japanese astronomers Akira Natori and Takeshi Urata at the JCPM Yakiimo Station on 23 November 1990.^[3] It was named for the Cheshire Cat from the novel Alice's Adventures in Wonderland.^[2]

6042 Cheshirecat

Discovery[1]
Discovered by	A. Natori T. Urata
Discovery site	JCPM Yakiimo Stn.
Discovery date	23 November 1990
Designations
MPC designation	(6042) Cheshirecat
Pronunciation	/ˈtʃɛʃərkæt/  · /ˈtʃɛʃɪərkæt/
Named after	Cheshire Cat (Alice in Wonderland)[2]
Alternative designations	1990 WW2
Minor planet category	Mars-crosser[1][3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	36.84 yr (13,454 days)
Aphelion	4.4295 AU
Perihelion	1.6505 AU
Semi-major axis	3.0400 AU
Eccentricity	0.4571
Orbital period (sidereal)	5.30 yr (1,936 days)
Mean anomaly	34.629°
Mean motion	0° 11m 9.24s / day
Inclination	15.885°
Longitude of ascending node	88.606°
Argument of perihelion	286.27°
Physical characteristics
Dimensions	14.12±0.20 km[5] 14.64 km (calculated)[4]
Synodic rotation period	10.049±0.004 h[6] 10.050±0.002 h[7]
Geometric albedo	0.109±0.004[5] 0.057 (assumed)[4]
Spectral type	XL[8] · K[9] · C[4]
Absolute magnitude (H)	12.00[9] · 12.30[5] · 12.77±0.62[8] · 12.9[1][4]

Classification and orbit

Cheshirecat is a Mars-crossing asteroid, as it crosses the orbit of Mars at 1.666 AU. It orbits the Sun at a distance of 1.65–4.43 AU once every 5 years and 4 months (1,936 days). Its orbit has an eccentricity of 0.46 and an inclination of 16° with respect to the ecliptic.^[1]

The body's observation arc begins 11 years prior to its official discovery observation, with a precovery taken at the Siding Spring Observatory in August 1979.^[3]

Physical characteristics

According to photometry from the Sloan Digital Sky Survey, Cheshirecat is a rare K-type asteroid.^[9] The asteroid has also been characterized as a XL-type – which transitions from the X-type to the L-type asteroid – by Pan-STARRS photometric survey.^[8]

Lightcurves

In December 2006, a rotational lightcurve of Cheshirecat was obtained from photometric observations by American astronomer Robert Stephens. Lightcurve analysis gave a rotation period of 10.050 hours with a brightness variation of 0.40 magnitude (U=3-).^[7] In September 2011, another lightcurve, obtained at the Oakley Southern Sky Observatory (E09), Australia, gave a concurring period of 10.050 hours and an amplitude of 0.20 (U=3-)^[6]

Diameter and albedo

According to the survey carried out by the Japanese Akari satellite, Cheshirecat measures 14.12 kilometers in diameter and its surface has an albedo of 0.109.^[5] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 14.64 kilometers based on an absolute magnitude of 12.9.^[4]

Naming

This minor planet was named for the Cheshire Cat, a cat appearing in Lewis Carroll's famous fairy tale Alice in Wonderland. The cat is known for its distinctive mischievous grins and eyes that linger after it has already faded away. The asteroid's name and citation was proposed by co-discoverer Takeshi Urata.^[2] The approved naming citation was published by the Minor Planet Center on 2 February 1999 (M.P.C. 33786).^[10]