The surprise comet of the year thus far is turning out to be Comet Lemmon (C/2012 F6). When discovered by Alex Gibbs on March 23, 2012 as part of the Mount Lemmon Survey, the comet was predicted to perhaps reach naked eye brightness on or around March 21, 2013. Amazingly and great news for comet watchers, Lemmon is currently brightening much faster than expected and its now believed that it could peak as high as magnitude 2. That could be even brighter than the much hyped, but currently disappointing Comet PanSTARRS (C/2011 L4).

Recent observations

On January 1, 2013 Lemmon was at magnitude 8.4. Despite no visible tail the comet displayed a 5 arc minutes diffuse coma with a definite bright centre. It continued to brighten by about 0.5 magnitudes a week and by the middle of January, Lemmon was up to magnitude 7.3 with a coma of the order of 7 to 8 arc minutes in diameter. On this date, the core had noticeably brightened with better definition. The coma appeared slightly elongated although still no tail. Since Lemmon is brightening at such a nice rate it wont be long before it attains naked eye visibility and by January 30, it was close to that scenario. With a magnitude of 6.2, the comet moved within easy binocular range. The coma on January 30 was up to 10 arc minutes in diameter with reports of a small tail visible in binoculars. In addition, Lemmon has a green look to it that's especially noticeable when imaged.

Location, magnitude and star chart

Comet Lemmon is continuing to move through the far southern constellations and is currently so far south it will pass close to the South Celestial Pole on February 5 and February 6. Consequently, during February it's well placed for observation from southern and tropical latitudes and from many of these locations it will be circumpolar and therefore never sets. In the Northern Hemisphere, the comet is not observable until May.

The comet starts February in the constellation of Chamaeleon before moving into Octans on February 2. At this point, it has a declination of 83 degrees south and is visible from practically the entire southern hemisphere. Lemmon then continues it southerly motion and passes within 4 degrees of the South Celestial Pole on February 5. With an estimate magnitude of 5.4 it should be visible to the naked eye, especially from dark sites, and a very easy binocular target. With any luck there should also be a small tail present.

Lemmon then begins moving north and will eventually cross the celestial equator before moving into far reaches of the northern part of the sky. Before then, on February 13 it moves into Tucana and on the following day passes 4 degrees west of globular cluster 47 Tucanae and the Small Magellanic Cloud. The comet then moves through Phoenix, into Sculptor and then onto Cetus and Pisces. Peak magnitude should occur on or around March 21, when hopefully Lemmon will be as bright as magnitude 2.4. Perihelion then follows on March 24, when it will be 0.7313 AU (109.4 million kms or 68.0 million miles) from the Sun.

Finder Chart for Comet Lemmon from January 23 to February 2, 2013 - pdf format

Finder Chart for Comet Lemmon from February 2 to February 12, 2013 - pdf format

Current visibility

During February, Lemmon can be seen from the southern hemisphere and from tropical locations. It stars February in the constellation of Chamaeleon, then moves through Octans and Tucana before ending the month in Phoenix. At no point in February does the declination of Lemmon move further north than 50 degrees south and hence the comet is well placed from the southern hemisphere and the tropics and even circumpolar for many observers at these latitudes.

Lemmon is not observable in the northern hemisphere until about May, when it should still be in good shape although gradually fading.

Comet Lemmon

Comet Lemmon (C/2012 F6) Data Table (data shown at 0:00 UT)

See also

Comet Lemmon (C/2012 F6) now fading but remains visible through small telescopes in the June morning sky
Comet Lemmon (C/2012 F6) now visible in the morning sky from the northern hemisphere
Comet Lemmon (C/2012 F6) returns to the morning sky for observers located at southern hemisphere and tropical latitudes
Comet Lemmon (C/2012 F6) temporarily unobservable as it moves from evening to morning sky
Comet Lemmon (C/2012 F6) closes in on maximum brightness
Naked eye Comet Lemmon (C/2012 F6) moves past 47 Tuc and SMC
Comet Lemmon (C/2012 F6) brightens faster than expected