C/1997 L1 (Zhu–Balam)

Comet Zhu–Balam, formally designated C/1997 L1, is a non-periodic comet first identified by David D. Balam on 8 June 1997, and originally photographed by Zhu Jin on 3 June 1997.^[5][6] The comet is estimated at 10 kilometres in diameter,^[5] with a period of approximately 36,895 years.^[4]

C/1997 L1 (Zhu-Balam)

Discovery[1]
Discovered by	Zhu Jin David D. Balam
Discovery site	Beijing, China Victoria, Australia
Discovery date	3–8 June 1997
Designations
Alternative designations	Comet Xinglong[2]
Orbital characteristics[3][4]
Epoch	22 August 1997 (JD 2450682.5)
Observation arc	453 days (1.24 years)
Number of observations	213
Aphelion	~4,800 AU
Perihelion	4.899 AU
Semi-major axis	~2,420 AU
Eccentricity	0.99797
Orbital period	~118,900 years
Inclination	72.991°
Longitude of ascending node	233.30°
Argument of periapsis	346.37°
Mean anomaly	0.002°
Last perihelion	22 November 1996
TJupiter	0.805
Earth MOID	3.9127 AU
Jupiter MOID	0.4171 AU
Physical characteristics[3][5]
Dimensions	10 km (6.2 mi)
Comet total magnitude (M1)	6.5
Comet nuclear magnitude (M2)	8.5

Until 1998, the comet was formerly known as Comet Xinglong,^[2] until the International Astronomical Union (IAU) agreed to rename it Zhu–Balam after its first two discoverers.^[7]

Orbit

Given the orbital eccentricity of this object, different epochs can generate quite different heliocentric unperturbed two-body best-fit solutions to the aphelion distance (maximum distance) of this object. For objects at such high eccentricity, the Sun's barycentric coordinates are more stable than heliocentric coordinates. Using JPL Horizons the barycentric orbital elements for epoch 2015-Jan-01 generate a semi-major axis of 1,100 AU and a period of approximately 36,895 years.^[4]