(9992) 1997 TG19

(9992) 1997 TG₁₉ is a stony asteroid and eccentric Mars-crosser, approximately 4 kilometers in diameter. It was discovered on 8 October 1997, by Japanese astronomers Tetsuo Kagawa and Takeshi Urata at Gekko Observatory near Shizuoka, Japan.^[8]

(9992) 1997 TG₁₉

Discovery[1]
Discovered by	T. Kagawa T. Urata
Discovery site	Gekko Obs.
Discovery date	8 October 1997
Designations
MPC designation	(9992) 1997 TG19
Alternative designations	1997 TG19 · 1974 HC1 1980 BD
Minor planet category	Mars-crosser[1][2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	42.77 yr (15,622 days)
Aphelion	2.8054 AU
Perihelion	1.5370 AU
Semi-major axis	2.1712 AU
Eccentricity	0.2921
Orbital period (sidereal)	3.20 yr (1,169 days)
Mean anomaly	154.42°
Mean motion	0° 18m 29.16s / day
Inclination	2.5944°
Longitude of ascending node	42.994°
Argument of perihelion	234.83°
Physical characteristics
Dimensions	3.07 km (derived)[2] 4.75±0.36 km[3]
Synodic rotation period	5.7300±0.0016 h[4] 5.7402±0.0005 h[5] 5.7408±0.0009 h[a]
Geometric albedo	0.137±0.022[3] 0.20 (assumed)[2]
Spectral type	S[2]
Absolute magnitude (H)	14.40[3] · 14.48±0.08 (R)[a] · 14.5[1] · 14.663±0.004 (R)[4] · 14.76±0.26[6] · 14.97±0.094[2][7]

Orbit and classification

Orbit of (9992) 1997 TG₁₉ (blue), compared to the inner planets and Jupiter (outermost)

The stony S-type asteroid orbits the Sun at a distance of 1.5–2.8 AU once every 3 years and 2 months (1,169 days). Its orbit has an eccentricity of 0.29 and an inclination of 3° with respect to the ecliptic.^[1] The first used observation was made at the Cerro El Roble Station in 1974, extending the asteroid's observation arc by 23 prior to its discovery.^[8]

Physical characteristics

Lightcurves

Between 2006 and 2013, three rotational lightcurves for this asteroid were obtained from photometric observations made at the Hunters Hill Observatory, Australia, the Ondřejov Observatory, Czech Republic, and the U.S. Palomar Transient Factory, California. They gave a well-defined, concurring rotation period of 5.7402±0.0005 hours (best result) with a brightness amplitude of 0.42, 0.40 and 0.27 in magnitude, respectively (U=3/3/2).^[a][4][5]

Diameter and albedo

According to the survey carried out by the Japanese Akari satellite, the asteroid's surface has an albedo of 0.13 and a diameter of 4.75 kilometers.^[3] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 3.1 kilometers, as the higher the body's albedo (reflectivity), the shorter its diameter, at a constant absolute magnitude (brightness).^[2]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 2 February 1999.^[9] As of 2018, it has not been named.^[8]

Notes

1. Pravec (2006) web: rotation period 5.7408±0.0009 hours with a brightness amplitude of 0.0009 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (9992) and Pravec − Results from Asteroid Photometry Project at Ondřejov Observatory