Shoemaker is a bright member of the dynamical Hungaria group that forms the innermost dense concentration of asteroids in the Solar System.[3] It orbits the Sun in the inner main-belt at a distance of 1.7–1.9 AU once every 2 years and 5 months (882 days). Its orbit has an eccentricity of 0.08 and an inclination of 30° with respect to the ecliptic.[1] With a perihelion of 1.6521 AU, Shoemaker is a Mars-crossing asteroid as it crosses the orbit of Mars at 1.666 AU.[1]
The body's observation arc begins with a precovery taken at Palomar in April 1954, more than 20 years prior to its official discovery observation.[4]
Several rotational lightcurve of Shoemaker were obtained from photometric observations by American astronomer Brian Warner at his Palmer Divide Observatory (716) and CS3-Station (U82). Analysis of the best-rated lightcurves gave a well-defined rotation period of 2.5328 hours with a brightness amplitude of 0.13 magnitude (U=3).[7][8][a]
Suspected binary
In October 2003, photometric observations of Shoemaker by Robert D. Stephens gave a long rotation period of 57.02 hours.[12] After re-measuring the images with newer software and calibration techniques, two mutual occultation and eclipsing events were found, indicating that Shoemaker might be a synchronous binary asteroid with a minor-planet moon orbiting it every 55 hours.[7] Observations in 2010, were difficult due to incomplete coverage and gave an orbital period of 27.39 hours for the secondary.[8] Observations by astronomers at Etscorn Campus Observatory (719) in 2015, did not mention any mutual events.[9]
In June 2017, Warner measured a rotation period of 2.5331±0.0002 hours and an orbital period for the secondary of 44.28 hours at his CS3-Palmer Divide Station in California.[a][b] The binary nature of Shoemaker remains unconfirmed.
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Shoemaker measures 3.18 and 3.22 kilometers in diameter and its surface has an albedo between 0.41 and 0.52, respectively.[5][6] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 4.93 kilometers based on an absolute magnitude of 13.9.[3]
^ abcWarner (2018b) web. Not yet in ADS. Observation 30 June 2017. Rotation period of 2.5331±0.0002 hours with a brightness amplitude of 0.09±0.01 mag. Quality code of 3. Summary figures for (2074) Shoemaker at Collaborative Asteroid Lightcurve Link (CALL)
^ abLightcurve plot of (2074) Shoemaker, Warner (2017), rotation period: 2.5331 hours; and second period (P2) of 44.28 hours. Quality code of 3.
^Lightcurve plot of (2074) Shoemaker, Warner (2015), period: of 2.809 and 2.515 hours. Quality code of 2.