2013 is gearing up nicely to be a superb year for bright comets. Already we have two comets that promise to be spectacular this year; Comet PanSTARRS (C/2011 L4) should peak at magnitude -1 in March and then later in the year comet ISON (C/2012 S1) may even reach the dizzy heights of magnitude -15 in November.

There is another comet that is currently brightening faster than expected and although will probably not be bright as the above-mentioned comets, it may prove to be the surprise package of the year. Its name is Comet Lemmon (C/2012 F6).

Discovery

Alex Gibbs of the Mount Lemmon Survey discovered Comet Lemmon on March 23, 2012. The Mount Lemmon Survey is part of the Catalina Sky Survey (CSS), a Near-Earth objects searching project, specifically aimed at finding potentially hazardous asteroids (PHAs) that may pose a threat of impact to Earth. Currently there are a number of telescopes participating in the survey, each of the order of 1-metre in aperture, located at various astronomical sites. The project is producing superb results with the Mount Lemmon telescope currently the most prolific telescope in the world for discovering Near-Earth Objects.

The objects discovered are often faint; Comet Lemmon was only magnitude 20.7 when found.

Location, magnitude and star chart

Comet Lemmon is currently moving through the southern part of the sky and hence nicely placed for southern hemisphere observers. On January 17 the comet begins its passage through the famous constellation of Crux. On this date, it was predicted to be of magnitude 7.7 and hence well within the reach of good binoculars.

Even better news still, recent observations of Comet Lemmon show it to be already about half a magnitude brighter than previously predicted and based on the current brightening, the comet should reach naked eye brightness during the first week of February. It is now looking promising that Comet Lemmon may peak at magnitude 3.0 on or around March 21, with an ion tail several degrees in length. Perihelion then follows on March 24, when this icy rock will be 0.7313 AU (109.4 million kms or 68.0 million miles) from the Sun.

During the above time period, Comet Lemmon travels southwards through Musca, Chamaeleon and into Octans where on February 4 it reaches its most southerly declination of -87 degrees, close to the South Celestial Pole. Of course, the comet is then circumpolar and never dips below the horizon for southern hemisphere astronomers. It then heads north through Tucana and an interesting visual and photo opportunity occurs on February 14, when comet Lemmon is located only 4 degrees to the west of globular cluster 47 Tucana and the Small Magellanic Cloud. After Tucana comes Phoenix, Sculptor, Cetus and Pisces where on April 19, Comet Lemmon crosses the celestial equator and moves into the northern section of the sky. Although now fainter, the comet is still predicted to be a naked eye object of about magnitude 5 on this date.

Finder Chart for Comet Lemmon from January 11 to January 24, 2013 - pdf format

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

Current visibility

At the moment, Comet Lemmon can be seen at is best for the southern hemisphere. Unfortunately, it is not visible for observers located in the northern hemisphere until about May. However, from the southern hemisphere it is currently high in the sky and will remain so for some time, especially during the end of February and March when it is at it's best.

Comet Lemmon

Name	C/2012 L6 (Lemmon)
Discovered By	A. R. Gibbs (Mount Lemmon Survey)
Discovery Date	March 23, 2012
Discovery Magnitude	20.7
Epoch	September 30, 2012
Aphelion (AU)	~1,000
Perihelion (AU)	0.7313
Eccentricity	0.9985
Orbital Period (years)	~11,000
Inclination (degrees)	82.61
Next perihelion	March 24, 2013

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

Date	Right Ascension	Declination	Mag.	Distance from Earth (AU)	Constellation
01 Jan 2013	12h 08m 47s	-36d 30m 59s	8.7	1.453	Centaurus
02 Jan 2013	12h 09m 44s	-37d 30m 17s	8.6	1.431	Centaurus
03 Jan 2013	12h 10m 41s	-38d 31m 12s	8.5	1.408	Centaurus
04 Jan 2013	12h 11m 39s	-39d 33m 49s	8.5	1.386	Centaurus
05 Jan 2013	12h 12m 38s	-40d 38m 08s	8.4	1.365	Centaurus
06 Jan 2013	12h 13m 37s	-41d 44m 14s	8.3	1.343	Centaurus
07 Jan 2013	12h 14m 38s	-42d 52m 09s	8.2	1.322	Centaurus
08 Jan 2013	12h 15m 40s	-44d 01m 55s	8.1	1.302	Centaurus
09 Jan 2013	12h 16m 44s	-45d 13m 35s	8.0	1.282	Centaurus
10 Jan 2013	12h 17m 49s	-46d 27m 10s	7.9	1.262	Centaurus
11 Jan 2013	12h 18m 56s	-47d 42m 43s	7.8	1.243	Centaurus
12 Jan 2013	12h 20m 05s	-49d 00m 16s	7.7	1.225	Centaurus
13 Jan 2013	12h 21m 17s	-50d 19m 49s	7.6	1.207	Centaurus
14 Jan 2013	12h 22m 31s	-51d 41m 24s	7.5	1.189	Centaurus
15 Jan 2013	12h 23m 49s	-53d 05m 00s	7.4	1.172	Centaurus
16 Jan 2013	12h 25m 10s	-54d 30m 39s	7.3	1.156	Centaurus
17 Jan 2013	12h 26m 36s	-55d 58m 20s	7.2	1.140	Crux
18 Jan 2013	12h 28m 08s	-57d 28m 01s	7.1	1.125	Crux
19 Jan 2013	12h 29m 45s	-58d 59m 42s	7.0	1.111	Crux
20 Jan 2013	12h 31m 31s	-60d 33m 19s	6.9	1.097	Crux
21 Jan 2013	12h 33m 25s	-62d 08m 49s	6.8	1.084	Crux
22 Jan 2013	12h 35m 30s	-63d 46m 09s	6.7	1.072	Crux
23 Jan 2013	12h 37m 49s	-65d 25m 13s	6.6	1.061	Musca
24 Jan 2013	12h 40m 25s	-67d 05m 56s	6.5	1.050	Musca
25 Jan 2013	12h 43m 22s	-68d 48m 10s	6.4	1.040	Musca
26 Jan 2013	12h 46m 47s	-70d 31m 46s	6.3	1.031	Musca
27 Jan 2013	12h 50m 47s	-72d 16m 33s	6.2	1.022	Musca
28 Jan 2013	12h 55m 37s	-74d 02m 20s	6.1	1.015	Musca
29 Jan 2013	13h 01m 34s	-75d 48m 50s	6.0	1.008	Chamaeleon
30 Jan 2013	13h 09m 08s	-77d 35m 42s	6.0	1.002	Chamaeleon
31 Jan 2013	13h 19m 08s	-79d 22m 27s	5.9	0.997	Chamaeleon
01 Feb 2013	13h 33m 01s	-81d 08m 19s	5.8	0.993	Chamaeleon
02 Feb 2013	13h 53m 34s	-82d 51m 56s	5.7	0.990	Chamaeleon
03 Feb 2013	14h 26m 35s	-84d 30m 30s	5.6	0.987	Octans
04 Feb 2013	15h 24m 57s	-85d 57m 10s	5.5	0.986	Octans
05 Feb 2013	17h 10m 36s	-86d 54m 06s	5.4	0.985	Octans
06 Feb 2013	19h 30m 30s	-86d 52m 06s	5.4	0.985	Octans
07 Feb 2013	21h 12m 28s	-85d 52m 57s	5.3	0.986	Octans
08 Feb 2013	22h 08m 28s	-84d 26m 15s	5.2	0.988	Octans
09 Feb 2013	22h 40m 17s	-82d 48m 51s	5.1	0.990	Octans
10 Feb 2013	23h 00m 09s	-81d 07m 09s	5.0	0.993	Octans
11 Feb 2013	23h 13m 36s	-79d 23m 47s	5.0	0.997	Octans
12 Feb 2013	23h 23m 15s	-77d 40m 01s	4.9	1.002	Octans
13 Feb 2013	23h 30m 31s	-75d 56m 31s	4.8	1.008	Octans
14 Feb 2013	23h 36m 11s	-74d 13m 44s	4.7	1.014	Tucana
15 Feb 2013	23h 40m 43s	-72d 31m 56s	4.7	1.020	Tucana
16 Feb 2013	23h 44m 27s	-70d 51m 20s	4.6	1.028	Tucana
17 Feb 2013	23h 47m 33s	-69d 12m 04s	4.5	1.036	Tucana
18 Feb 2013	23h 50m 11s	-67d 34m 14s	4.5	1.044	Tucana
19 Feb 2013	23h 52m 26s	-65d 57m 54s	4.4	1.053	Tucana
20 Feb 2013	23h 54m 24s	-64d 23m 09s	4.3	1.063	Tucana
21 Feb 2013	23h 56m 06s	-62d 50m 01s	4.3	1.073	Tucana
22 Feb 2013	23h 57m 36s	-61d 18m 30s	4.2	1.084	Tucana
23 Feb 2013	23h 58m 56s	-59d 48m 37s	4.1	1.094	Tucana
24 Feb 2013	00h 00m 07s	-58d 20m 22s	4.1	1.106	Tucana
25 Feb 2013	00h 01m 10s	-56d 53m 45s	4.0	1.117	Phoenix
26 Feb 2013	00h 02m 07s	-55d 28m 43s	3.9	1.129	Phoenix
27 Feb 2013	00h 02m 58s	-54d 05m 15s	3.9	1.142	Phoenix
28 Feb 2013	00h 03m 43s	-52d 43m 20s	3.8	1.154	Phoenix

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) now naked eye and continues to improve