1989 Tatry

1989 Tatry, provisional designation 1955 FG, is a carbonaceous Vestian asteroid and tumbling slow rotator from the inner regions of the asteroid belt, approximately 16 kilometers in diameter.

1989 Tatry

Discovery[1]
Discovered by	A. Paroubek R. Podstanicka
Discovery site	Skalnaté Pleso Obs.
Discovery date	20 March 1955
Designations
MPC designation	(1989) Tatry
Named after	High Tatra Mountains (in northern Slovakia)[2]
Alternative designations	1955 FG · 1935 UQ 1944 DL · 1955 DY 1964 WK · 1968 YC 1971 SJ2
Minor planet category	main-belt · Vestian[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	81.63 yr (29,815 days)
Aphelion	2.5314 AU
Perihelion	2.1704 AU
Semi-major axis	2.3509 AU
Eccentricity	0.0768
Orbital period (sidereal)	3.60 yr (1,317 days)
Mean anomaly	166.59°
Mean motion	0° 16m 24.24s / day
Inclination	7.7654°
Longitude of ascending node	25.305°
Argument of perihelion	88.343°
Physical characteristics
Dimensions	8.99±2.38 km[4] 9.399±0.122 km[5] 9.603±0.063 km[6] 9.87±0.88 km[7] 16.81 km (calculated)[3]
Synodic rotation period	24 h[8] 39.9±0.1 h[9] 131.3±0.2 h[10]
Geometric albedo	0.057 (assumed)[3] 0.175±0.017[5] 0.1917±0.0338[6] 0.240±0.205[4] 0.262±0.048[7]
Spectral type	SMASS = C[1][3]
Absolute magnitude (H)	12.10[7] · 12.10±0.91[11] · 12.40[4] · 12.5[6] · 12.6[1][3]

It was discovered on 20 March 1955, by the Slovakian astronomers Alois Paroubek and Regina Podstanická at Skalnate Pleso Observatory, Slovakia, and named for the High Tatra Mountains.^[2][12] It was their only minor planet discovery.

Orbit and classification

Based on its orbital elements, the asteroid is a member of the Vesta family and classified as a carbonaceous C-type asteroid in the SMASS taxonomy. It orbits the Sun in the inner main-belt at a distance of 2.2–2.5 AU once every 3 years and 7 months (1,317 days). Its orbit has an eccentricity of 0.08 and an inclination of 8° with respect to the ecliptic.^[1] It was first identified as 1935 UQ at the South African Union Observatory in 1935, extending the asteroid's observation arc by 20 years prior to its official discovery.^[12]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures between 8.99 and 9.87 kilometers in diameter and its surface has an albedo between 0.175 and 0.262.^[4][5][6][7] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a much larger diameter of 16.8 kilometers, as the lower the albedo (reflectivity), the higher the diameter at a constant absolute magnitude (brightness).^[3]

Lightcurves

Photometric measurements of the asteroid made in January 2005, by astronomer Brian D. Warner at his Palmer Divide Observatory, Colorado, gave a lightcurve with a period of 39.9±0.1 hours and a brightness variation of below 0.22±0.02 in magnitude. However, the data was incomplete, so the period is considered suspect (U=2-).^[9] Further measurements made in October 2007, by Adrián Galád, Leonard Kornoš and Štefan Gajdoš at Modra Observatory in Slovakia, showed a much longer period of 131.3±0.2 hours with a brightness variation of 0.5 in magnitude (U=2).^[10] In March 2009, a fragmentary lightcurve obtained by French amateur astronomer Pierre Antonini gave a period of 24 hours (U=1).^[8]

Tumbler

The observers also detected a non-principal axis rotation seen in distinct rotational cycles in successive order. This is commonly known as tumbling.^[3][10][13] Tatry is one of a group of less than 200 bodies known to be is such a state (also see List of tumblers).

Naming

This minor planet is named after the location of the discovering observatory, High Tatras (Slovak: Vysoké Tatry), the highest mountain range in northern Slovakia.^[2] The approved naming citation was published by the Minor Planet Center on 1 February 1980 (M.P.C. 5183).^[14]