C/2012 F6 (Lemmon)

C/2012 F6 (Lemmon)

Comet Lemmon in Tucana on 16 February 2013
Discovery
Discovered by	A. R. Gibbs Mt. Lemmon Survey (G96)[1]
Discovery date	23 March 2012
Orbital characteristics
Epoch	28 October 2012 (JD 2456228.5)
Aphelion	973.47895 AU (Q)
Perihelion	0.73126 AU (q)
Semi-major axis	487.1051 AU (a)
Eccentricity	0.99850 (e)
Orbital period	~8000 yr (Barycentric solution for epoch 2050)[2]
Inclination	82.60839° (i)
Last perihelion	2013-03-24.516

C/2012 F6 (Lemmon) is a long-period comet discovered in Leo on 23 March 2012, by A. R. Gibbs^[1] using the 1.5-m reflector at the Mt. Lemmon Survey, located at the summit of Mount Lemmon in the Santa Catalina Mountains north of Tucson, Arizona, USA. Initially, the object was considered to be of asteroidal nature before later observations confirmed its cometary appearance. Comet Lemmon has a highly eccentric orbit, bringing it as close to 0.73 AU from the Sun at perihelion and as far as 973 AU from the Sun at aphelion. This also leads to the comet's long-period nature with an orbital period of approximately 8,000 years based on epoch 2050. The comet last reached perihelion on 24 March 2013.

For much of 2012, observation of Lemmon remained limited to CCD imagery, but steadily brightened throughout the course of the year. In late-November 2012, the comet became bright enough for telescopic viewing, and had an apparent magnitude estimated at +9 by the year's end. Brightening continued into the early months of 2013 before peaking at an apparent magnitude of +5 in late March, though viewing was mostly limited to the Southern Hemisphere. On 24 March 2013, Lemmon reached its orbital perihelion and afterwards began to dim. On 20 April 2013, Lemmon crossed the celestial equator and became primarily viewable in the Northern Hemisphere, though by this time the comet was significantly dimmer relative to its peak brightness.^[3]