C/2019 O3 (Palomar)

For other comets of the same name, see Comet Palomar.

C/2019 O3 (Palomar) is a distant Oort cloud comet that came to perihelion on 8 March 2021 at a distance of 8.82 AU (1.319 billion km) from the Sun. It is discovered from the Palomar Observatory in July 2019, and is one of eight comets named after it.^[1]

C/2019 O3 (Palomar)

Discovery[1]
Discovery site	Palomar Observatory
Discovery date	26 July 2019
Orbital characteristics[2][3]
Epoch	22 March 2022 (JD 2459660.5)
Observation arc	5.71 years
Earliest precovery date	14 May 2019
Number of observations	2,138
Aphelion	~58,000 AU (inbound) ~14,000 AU (outbound)
Perihelion	8.820 AU
Semi-major axis	~29,000 AU (inbound) ~7,000 AU (outbound)
Eccentricity	0.99969 (inbound) 0.99874 (outbound)
Orbital period	~4.9 million years (inbound) ~590,000 years (outbound)
Inclination	89.819°
Longitude of ascending node	300.39°
Argument of periapsis	60.096°
Mean anomaly	0.0031°
Last perihelion	8 March 2021
Earth MOID	8.273 AU
Jupiter MOID	5.492 AU
Physical characteristics[4]
Mean radius	>7.9 km (4.9 mi)[5]
Spectral type	(B−V) = 0.75±0.03 (V−R) = 0.47±0.03 (V−I) = 0.94±0.09
Comet total magnitude (M1)	6.1[3]
Comet nuclear magnitude (M2)	8.0[3]
Apparent magnitude	13.6 (2021 apparition)[6]