C/2012 X1 (LINEAR)

For other comets of the same name, see List of comets discovered by the LINEAR project.

Comet LINEAR, formal designation C/2012 X1, is a non-periodic comet that was observed telescopically from 2012 to 2015. It produced a powerful outburst on 21 October 2013, which raised its brightness 100 times its expected magnitude from 12 to 8.5 for several months.^[5]

C/2012 X1 (LINEAR)

The comet on 18 May 2014 by NEOWISE
Discovery[1]
Discovered by	LINEAR
Discovery site	Socorro, New Mexico
Discovery date	8 December 2012
Designations
Alternative designations	CK12X010[2]
Orbital characteristics[3]
Epoch	18 December 2013 (JD 2456644.5)
Observation arc	1,038 days (2.84 years)
Aphelion	305.1 AU
Perihelion	1.599 AU
Semi-major axis	153.33 AU
Eccentricity	0.98957
Orbital period	~1,900 years
Max. orbital speed	33.2 km/s
Inclination	44.367°
Longitude of ascending node	113.146°
Argument of periapsis	132.114°
Last perihelion	21 February 2014
TJupiter	1.152
Earth MOID	0.752 AU
Jupiter MOID	1.066 AU
Physical characteristics[4]
Dimensions	1.8–3.6 km (1.1–2.2 mi)
Mean diameter	2.8 km (1.7 mi)
Comet total magnitude (M1)	5.5
Comet nuclear magnitude (M2)	10.8
Apparent magnitude	8.5 (2013 apparition)

Discovery and observations

An asteroid-like object with an apparent magnitude of 19.4 was spotted with cometary activity from images taken by the Lincoln Near-Earth Asteroid Research survey on the night of 8 December 2012.^[1]

From April 2014 onwards, the comet slowly faded away as it made its way back to the outer Solar System. It was last observed from Australia as a 20th-magnitude object about 7.0 AU (1.05 billion km) from the Sun on 9 December 2015.