Better than expected Comet Lemmon (C/2012 F6) reached naked eye visibility during February and remains well placed for the remainder of the month for observers located in the southern hemisphere. The comet that was discovered by Alex Gibbs on March 23, 2012 and has so far proved to be a small revelation, brightening much faster than expected. If current trends continue then Lemmon should peak at around magnitude 2 on March 21; no less than 3 magnitudes brighter than originally thought.
Recent observations
On February 1, 2013 Lemmon glowed at magnitude 6.0, displayed an elongated coma of 10 arc minutes with a small faint tail towards the northwest. It was an extremely difficult naked eye object, faintly visible from dark sites with the assistance of averted vision. Five days later Lemmon had brightened to magnitude 5.6 and hence a more attainable naked eye target. However, as with all faint diffuse objects at this magnitude, any sort of light pollution or light interference rendered the comet invisible. The elongated coma had now increased to 15 arc minutes with a small increase in the size of the tail. Through 10x50 binoculars it appeared obviously non-stellar, not unlike the binocular view of a distant globular cluster. Lemmon continued to improve and a few days later on February 11, it was up to magnitude 5.4 with a slightly larger coma and tail. This time through 10x50 binoculars, the tail extended at least 30 arc minutes in a southeasterly direction.
Location, magnitude and star chart
Comet Lemmon has now passed its most southerly point in the sky and is now heading northwards. It was so far south that on February 5, the comet passed less than 4 degrees from the South Celestial Pole and therefore circumpolar for practically all observers located in the entire southern hemisphere.
Currently Lemmon is very much a southern hemisphere comet (and to a lesser extent a tropical comet). Despite now heading on a northern bearing, northern hemisphere observers will have to wait until May to catch a look at the comet. Until them it remains in good shape for their southern hemisphere counterparts.
The finder charts below show the path of Comet Lemmon against the background stars from February 2 to February 12, 2013 and from February 11 to February 22, 2013. After starting February in Chamaeleon, Lemmon moves through Octans (February 2 to February 13) and then into Tucana. Between February 14 and February 16, the comet slides by the show stopping globular cluster 47 Tucanae and the impressive Small Magellanic Cloud. At the point of closest approach, Lemmon will be about 4 degrees west of 47 Tucanae. With a magnitude of 4.6, it shouldn't be too difficult a naked eye target. Both objects will also fit in the same binocular field of view.
Finder Chart for Comet Lemmon from February 2 to February 12, 2013 - pdf format
Finder Chart for Comet Lemmon from February 11 to February 22, 2013 - pdf format
The comet then passes into Phoenix on February 24, remaining there until March 10. After that it continues into Sculptor, then Cetus and onto Pisces. Peak brightness should occur on or around March 21 with a revised estimate of magnitude 2.4. Perihelion then follows on March 24, when Lemmon will be 0.7313 AU (109.4 million kms or 68.0 million miles) from the Sun.
Current visibility
From the southern hemisphere, Lemmon starts February high in the southern evening sky. It remains circumpolar for latitudes further south than 40S during February but appears lower in the sky as the month ends. At the equator, Lemmon is visible very low down in the southern evening twilight sky during the second part of the month.
Comet Lemmon is not observable in the northern hemisphere until about May. Although fading it should still be of the order of 5th magnitude.
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 |
|---|---|---|---|---|---|
| 10 Feb 2013 | 23h 00m 09s | -81d 07m 09s | 5.2 | 0.993 | Octans |
| 11 Feb 2013 | 23h 13m 36s | -79d 23m 47s | 5.1 | 0.997 | Octans |
| 12 Feb 2013 | 23h 23m 15s | -77d 40m 01s | 5.0 | 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 | 4.6 | 1.020 | Tucana |
| 16 Feb 2013 | 23h 44m 27s | -70d 51m 20s | 4.5 | 1.028 | Tucana |
| 17 Feb 2013 | 23h 47m 33s | -69d 12m 04s | 4.4 | 1.036 | Tucana |
| 18 Feb 2013 | 23h 50m 11s | -67d 34m 14s | 4.3 | 1.044 | Tucana |
| 19 Feb 2013 | 23h 52m 26s | -65d 57m 54s | 4.2 | 1.053 | Tucana |
| 20 Feb 2013 | 23h 54m 24s | -64d 23m 09s | 4.1 | 1.063 | Tucana |
| 21 Feb 2013 | 23h 56m 06s | -62d 50m 01s | 4.0 | 1.073 | Tucana |
| 22 Feb 2013 | 23h 57m 36s | -61d 18m 30s | 3.9 | 1.084 | Tucana |
| 23 Feb 2013 | 23h 58m 56s | -59d 48m 37s | 3.8 | 1.094 | Tucana |
| 24 Feb 2013 | 00h 00m 07s | -58d 20m 22s | 3.7 | 1.106 | Tucana |
| 25 Feb 2013 | 00h 01m 10s | -56d 53m 45s | 3.7 | 1.117 | Phoenix |
| 26 Feb 2013 | 00h 02m 07s | -55d 28m 43s | 3.6 | 1.129 | Phoenix |
| 27 Feb 2013 | 00h 02m 58s | -54d 05m 15s | 3.6 | 1.142 | Phoenix |
| 28 Feb 2013 | 00h 03m 43s | -52d 43m 20s | 3.5 | 1.154 | Phoenix |
| 01 Mar 2013 | 00h 04m 25s | -51d 22m 54s | 3.4 | 1.167 | Phoenix |
| 02 Mar 2013 | 00h 05m 02s | -50d 03m 55s | 3.3 | 1.180 | Phoenix |
| 03 Mar 2013 | 00h 05m 36s | -48d 46m 21s | 3.3 | 1.193 | Phoenix |
| 04 Mar 2013 | 00h 06m 06s | -47d 30m 08s | 3.2 | 1.206 | Phoenix |
| 05 Mar 2013 | 00h 06m 33s | -46d 15m 13s | 3.2 | 1.219 | Phoenix |
| 06 Mar 2013 | 00h 06m 58s | -45d 01m 34s | 3.1 | 1.233 | Phoenix |
| 07 Mar 2013 | 00h 07m 20s | -43d 49m 06s | 3.0 | 1.246 | Phoenix |
| 08 Mar 2013 | 00h 07m 40s | -42d 37m 47s | 3.0 | 1.260 | Phoenix |
| 09 Mar 2013 | 00h 07m 58s | -41d 27m 34s | 2.9 | 1.274 | Phoenix |
| 10 Mar 2013 | 00h 08m 14s | -40d 18m 23s | 2.9 | 1.287 | Phoenix |
| 11 Mar 2013 | 00h 08m 28s | -39d 10m 10s | 2.8 | 1.301 | Sculptor |
| 12 Mar 2013 | 00h 08m 41s | -38d 02m 54s | 2.8 | 1.314 | Sculptor |
| 13 Mar 2013 | 00h 08m 53s | -36d 56m 31s | 2.8 | 1.328 | Sculptor |
| 14 Mar 2013 | 00h 09m 03s | -35d 50m 57s | 2.7 | 1.341 | Sculptor |
| 15 Mar 2013 | 00h 09m 12s | -34d 46m 10s | 2.7 | 1.354 | Sculptor |
| 16 Mar 2013 | 00h 09m 20s | -33d 42m 08s | 2.6 | 1.368 | Sculptor |
| 17 Mar 2013 | 00h 09m 27s | -32d 38m 48s | 2.6 | 1.381 | Sculptor |
| 18 Mar 2013 | 00h 09m 34s | -31d 36m 06s | 2.6 | 1.393 | Sculptor |
| 19 Mar 2013 | 00h 09m 39s | -30d 34m 02s | 2.5 | 1.406 | Sculptor |
| 20 Mar 2013 | 00h 09m 45s | -29d 32m 32s | 2.5 | 1.418 | Sculptor |
| 21 Mar 2013 | 00h 09m 49s | -28d 31m 35s | 2.4 | 1.430 | Sculptor |
| 22 Mar 2013 | 00h 09m 54s | -27d 31m 08s | 2.5 | 1.442 | Sculptor |
| 23 Mar 2013 | 00h 09m 58s | -26d 31m 11s | 2.5 | 1.454 | Sculptor |
| 24 Mar 2013 | 00h 10m 02s | -25d 31m 40s | 2.6 | 1.466 | Sculptor |
| 25 Mar 2013 | 00h 10m 05s | -24d 32m 36s | 2.6 | 1.477 | Cetus |
| 26 Mar 2013 | 00h 10m 09s | -23d 33m 57s | 2.6 | 1.488 | Cetus |
| 27 Mar 2013 | 00h 10m 13s | -22d 35m 40s | 2.7 | 1.498 | Cetus |
| 28 Mar 2013 | 00h 10m 17s | -21d 37m 46s | 2.7 | 1.509 | Cetus |
| 29 Mar 2013 | 00h 10m 21s | -20d 40m 14s | 2.8 | 1.519 | Cetus |
| 30 Mar 2013 | 00h 10m 26s | -19d 43m 02s | 2.9 | 1.529 | Cetus |
| 31 Mar 2013 | 00h 10m 31s | -18d 46m 09s | 2.9 | 1.538 | Cetus |
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
Comet Lemmon (C/2012 F6) now naked eye and continues to improve
Comet Lemmon (C/2012 F6) brightens faster than expected