November promises to be an exciting time for all as predicted wonder comet ISON reaches perihelion at the end of the month. The comet, discovered at the end of last year, has an orbit that brings it within only 0.01249 AU (1.87 million kilometres or 1.16 million miles) of the Sun. When a comet approaches our star at such a small distance anything is possible - equally possible a spectacular object visible during daytime or a disintegrating ball of ice and dust that fades away into oblivion.
ISON is currently predicted to reach naked eye magnitude on or around November 21st. It then continues to increase in brightness until it peaks on November 29th, the date of perihelion. It's now believed for a short time that ISON could reach magnitude -6. However, as with all comets nobody can be certain and it could be magnitudes brighter or magnitudes fainter than this value. After perihelion the comet will rapidly decrease in brightness but still remain visible to the naked eye for at least another week or so.
The best location to observe ISON is from the Northern Hemisphere. It will be observable in the early morning sky towards the east throughout the brightening period. Observers in the Southern Hemisphere don't have it as good as their northern counterparts, ISON remains low down throughout this time.
The finder chart below shows the path of ISON from October 28th to November 15th. During this time it moves from Leo into Virgo and brightens from magnitude +9.9 to +7.0. It should then be within the range of binoculars.
Comet ISON Finder Chart from October 28 to November 15, 2013 - pdf format
Comet ISON (C/2012 S1) Data (at epoch February 28, 2013)
| Name | C/2012 S1 (ISON) |
|---|---|
| Type | Comet |
| Classification | Hyperbolic Comet |
| Discoverer | Vitali Nevski and Artyom Novichonok using the ISON group of telescopes |
| Discovery date | September 21, 2012 |
| Aphelion (AU) | unknown |
| Perihelion (AU) | 0.01249 |
| Eccentricity | 1.000005 |
| Orbital period (years) | unknown |
| Inclination (degrees) | 61.981 |
| Longitude of ascending node (degrees) | 295.716 |
| Perihelion | November 28th, 2013 |
| Notes | Sungrazing comet |
Comet ISON (C/2012 S1) Data Table
| Date | Right Ascension | Declination | Estimated Magnitude | Distance from Earth (AU) | Constellation |
|---|---|---|---|---|---|
| 28 Oct 2013 | 10h 53m 49s | 08d 43m 59s | 9.9 | 1.344 | Leo |
| 29 Oct 2013 | 10h 58m 12s | 08d 10m 56s | 9.7 | 1.315 | Leo |
| 30 Oct 2013 | 11h 02m 44s | 07d 36m 16s | 9.6 | 1.286 | Leo |
| 31 Oct 2013 | 11h 07m 28s | 06d 59m 53s | 9.5 | 1.258 | Leo |
| 01 Nov 2013 | 11h 12m 24s | 06d 21m 39s | 9.3 | 1.230 | Leo |
| 02 Nov 2013 | 11h 17m 33s | 05d 41m 28s | 9.2 | 1.202 | Leo |
| 03 Nov 2013 | 11h 22m 56s | 04d 59m 13s | 9.1 | 1.175 | Leo |
| 04 Nov 2013 | 11h 28m 33s | 04d 14m 46s | 8.9 | 1.148 | Leo |
| 05 Nov 2013 | 11h 34m 27s | 03d 27m 58s | 8.8 | 1.122 | Leo |
| 06 Nov 2013 | 11h 40m 37s | 02d 38m 44s | 8.6 | 1.096 | Virgo |
| 07 Nov 2013 | 11h 47m 05s | 01d 46m 54s | 8.5 | 1.072 | Virgo |
| 08 Nov 2013 | 11h 53m 53s | 00d 52m 22s | 8.3 | 1.047 | Virgo |
| 09 Nov 2013 | 12h 01m 02s | -00d 04m 59s | 8.1 | 1.024 | Virgo |
| 10 Nov 2013 | 12h 08m 33s | -01d 05m 14s | 8.0 | 1.002 | Virgo |
| 11 Nov 2013 | 12h 16m 28s | -02d 08m 26s | 7.8 | 0.980 | Virgo |
| 12 Nov 2013 | 12h 24m 48s | -03d 14m 38s | 7.6 | 0.960 | Virgo |
| 13 Nov 2013 | 12h 33m 35s | -04d 23m 48s | 7.4 | 0.941 | Virgo |
| 14 Nov 2013 | 12h 42m 50s | -05d 35m 52s | 7.2 | 0.924 | Virgo |
| 15 Nov 2013 | 12h 52m 34s | -06d 50m 42s | 7.0 | 0.908 | Virgo |
| 16 Nov 2013 | 13h 02m 50s | -08d 08m 02s | 6.8 | 0.894 | Virgo |
| 17 Nov 2013 | 13h 13m 38s | -09d 27m 35s | 6.6 | 0.881 | Virgo |
| 18 Nov 2013 | 13h 25m 00s | -10d 48m 53s | 6.4 | 0.871 | Virgo |
| 19 Nov 2013 | 13h 36m 57s | -12d 11m 24s | 6.1 | 0.864 | Virgo |
| 20 Nov 2013 | 13h 49m 29s | -13d 34m 26s | 5.8 | 0.858 | Virgo |
| 21 Nov 2013 | 14h 02m 36s | -14d 57m 12s | 5.6 | 0.856 | Virgo |
| 22 Nov 2013 | 14h 16m 21s | -16d 18m 46s | 5.2 | 0.857 | Virgo |
| 23 Nov 2013 | 14h 30m 43s | -17d 38m 06s | 4.9 | 0.861 | Libra |
| 24 Nov 2013 | 14h 45m 44s | -18d 54m 03s | 4.4 | 0.869 | Libra |
| 25 Nov 2013 | 15h 01m 29s | -20d 05m 16s | 3.9 | 0.882 | Libra |
| 26 Nov 2013 | 15h 18m 06s | -21d 10m 03s | 3.2 | 0.900 | Libra |
| 27 Nov 2013 | 15h 36m 00s | -22d 05m 35s | 2.1 | 0.924 | Libra |
| 28 Nov 2013 | 15h 56m 31s | -22d 43m 30s | 0.1 | 0.960 | Scorpius |
| 29 Nov 2013 | 16h 23m 17s | -19d 52m 17s | -3.1 | 0.976 | Scorpius |
| 30 Nov 2013 | 16h 21m 22s | -16d 20m 14s | 1.2 | 0.912 | Scorpius |
| 01 Dec 2013 | 16h 19m 11s | -13d 58m 52s | 2.6 | 0.868 | Scorpius |
| 02 Dec 2013 | 16h 17m 23s | -11d 55m 49s | 3.4 | 0.831 | Scorpius |
| 03 Dec 2013 | 16h 15m 54s | -10d 00m 41s | 3.9 | 0.798 | Scorpius |
| 04 Dec 2013 | 16h 14m 39s | -08d 09m 09s | 4.4 | 0.768 | Ophiuchus |
| 05 Dec 2013 | 16h 13m 36s | -06d 18m 51s | 4.7 | 0.740 | Ophiuchus |
| 06 Dec 2013 | 16h 12m 44s | -04d 28m 14s | 5.0 | 0.714 | Ophiuchus |
| 07 Dec 2013 | 16h 12m 02s | -02d 36m 10s | 5.2 | 0.690 | Serpens Caput |
| 08 Dec 2013 | 16h 11m 27s | 00d 41m 45s | 5.4 | 0.667 | Serpens Caput |
| 09 Dec 2013 | 16h 11m 00s | 01d 15m 45s | 5.6 | 0.644 | Serpens Caput |
| 10 Dec 2013 | 16h 10m 41s | 03d 17m 02s | 5.7 | 0.623 | Serpens Caput |
| 11 Dec 2013 | 16h 10m 27s | 05d 22m 41s | 5.9 | 0.603 | Serpens Caput |
| 12 Dec 2013 | 16h 10m 20s | 07d 33m 18s | 6.0 | 0.584 | Serpens Caput |
| 13 Dec 2013 | 16h 10m 19s | 09d 49m 24s | 6.1 | 0.566 | Serpens Caput |
| 14 Dec 2013 | 16h 10m 24s | 12d 11m 29s | 6.2 | 0.549 | Serpens Caput |
| 15 Dec 2013 | 16h 10m 34s | 14d 39m 59s | 6.3 | 0.532 | Serpens Caput |
| 16 Dec 2013 | 16h 10m 51s | 17d 15m 19s | 6.3 | 0.517 | Hercules |
| 17 Dec 2013 | 16h 11m 13s | 19d 57m 46s | 6.4 | 0.503 | Hercules |
| 18 Dec 2013 | 16h 11m 41s | 22d 47m 33s | 6.5 | 0.489 | Hercules |
| 19 Dec 2013 | 16h 12m 16s | 25d 44m 46s | 6.5 | 0.477 | Corona Borealis |
| 20 Dec 2013 | 16h 12m 58s | 28d 49m 21s | 6.6 | 0.466 | Corona Borealis |
| 21 Dec 2013 | 16h 13m 47s | 32d 01m 04s | 6.7 | 0.457 | Corona Borealis |
| 22 Dec 2013 | 16h 14m 44s | 35d 19m 30s | 6.7 | 0.448 | Corona Borealis |
| 23 Dec 2013 | 16h 15m 51s | 38d 43m 59s | 6.8 | 0.442 | Corona Borealis |
| 24 Dec 2013 | 16h 17m 07s | 42d 13m 39s | 6.9 | 0.436 | Hercules |
| 25 Dec 2013 | 16h 18m 36s | 45d 47m 25s | 6.9 | 0.432 | Hercules |
| 26 Dec 2013 | 16h 20m 19s | 49d 24m 02s | 7.0 | 0.430 | Hercules |
| 27 Dec 2013 | 16h 22m 19s | 53d 02m 04s | 7.1 | 0.429 | Draco |
| 28 Dec 2013 | 16h 24m 41s | 56d 40m 01s | 7.2 | 0.430 | Draco |
| 29 Dec 2013 | 16h 27m 31s | 60d 16m 21s | 7.3 | 0.433 | Draco |
| 30 Dec 2013 | 16h 30m 57s | 63d 49m 32s | 7.4 | 0.437 | Draco |
| 31 Dec 2013 | 16h 35m 13s | 67d 18m 09s | 7.5 | 0.442 | Draco |
See also
Comet ISON (C/2012 S1) brightens as it nears Mars fly-by
How to find Comet ISON (C/2012 S1) as it heads towards perihelion