Tsuchinshan–ATLAS

C/2023 A3 (Tsuchinshan–ATLAS) is a comet from the Oort cloud. It was discovered in 2023, by the Purple Mountain Observatory in China; A few weeks later, the comet was found (independently) by ATLAS South Africa; The comet passed perihelion at a distance of 0.39 AU (58 million km; 36 million mi) on 27 September 2024,^[4][2] when it became visible to the naked eye.^[5][6]

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C/2023 A3 (Tsuchinshan–ATLAS)

The comet on 2 October 2024, taken in Victoria, Australia
Discovery
Discovered by	Purple Mountain Observatory ATLAS South Africa
Discovery date	9 January 2023[4]
Alternative designations	A10SVYR
Orbital characteristics A
Number of observations	2060
Aphelion	≈ 270,000 AU (inbound)[3] ≈ 3,800 AU (outbound)[3]
Perihelion	0.3914 AU (58.6 million km)[2]
Eccentricity	0.9999985 (epoch 1800)[3] 0.9998981 (epoch 2200)
Orbital period	≈ 110 million years (inbound)[3] ≈ 235,000 years (outbound)[3]
Max. orbital speed	67.33 km/s @ perihelion[2]
Inclination	139.1°
Earth MOID	0.275 AU (41.1 million km; 107 LD)[1]
Comet total magnitude (M1)	4.3 ± 0.3[1]
Comet nuclear magnitude (M2)	9.2 ± 0.3[1]
Last perihelion	27 September 2024 18:00 ± 20 minutes (3-sigma)[2][1]