996 Hilaritas

996 Hilaritas

Discovery
Discovered by	J. Palisa
Discovery site	Vienna
Discovery date	21 March 1923
Designations
Alternative names	1923 NM
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	88.16 yr (32200 days)
Aphelion	3.5220 AU (526.88 Gm)
Perihelion	2.6535 AU (396.96 Gm)
Semi-major axis	3.0878 AU (461.93 Gm)
Eccentricity	0.14063
Orbital period	5.43 yr (1981.8 d)
Mean anomaly	93.831°
Mean motion	0° 10^m 53.94^s / day
Inclination	0.65948°
Longitude of ascending node	347.404°
Argument of perihelion	147.140°
Earth MOID	1.66636 AU (249.284 Gm)
Jupiter MOID	1.52147 AU (227.609 Gm)
Jupiter Tisserand parameter	3.210
Physical characteristics
Mean radius	14.765±0.65 km
Rotation period	10.05 h (0.419 d)
Geometric albedo	0.0901±0.009
Absolute magnitude (H)	10.88

996 Hilaritas is a Themistian asteroid. It was discovered in 1923 by Austrian astronomer Johann Palisa. Following Palisa's death in 1925, this asteroid was named for a "happy or contented mind"; qualities associated with the discoverer.^[2]

Photometric observations of this asteroid collected during 2010 show a rotation period of 10.052 ± 0.001 hours with a brightness variation of 0.65 ± 0.03 magnitude.^[3]

References

1. "996 Hilaritas (1923 NM)". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 2 May 2016.
2. Schmadel, Lutz D. (2012), Dictionary of Minor Planet Names (6th ed.), Springer, p. 85, ISBN 3642297188.
3. Strabla, Luca; Quadri, Ulisse; Girelli, Roberto (January 2011), "Lightcurve Analysis of 996 Hilaritas", The Minor Planet Bulletin 38 (1): 14–15, Bibcode:2011MPBu...38...14S.

External links

• Discovery Circumstances: Numbered Minor Planets
• 996 Hilaritas at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters