Comet 96P/Machholz 1 or 96P/Machholz is now brightening rapidly as its heads towards a very close pass of the Sun on July 14, 2012. As of July 1, the magnitude of this short period comet was approx. 9.3 but is predicted - although comet predictions have historically often been way off the mark - to reach a peak magnitude of 2.2 around perihelion. When at its brightest, it is sweeping round the Sun and temporarily lost from view from Earth.
As quickly as it brightens it will fade and by the end of the month it is expected to be back down to magnitude 9. Therefore, the window of opportunity to catch a glimpse of this elusive object is a short one. The charts below show the movement of Comet 96P/Machholz 1 against the stars before, during and after perihelion.
Comet Machholz finder chart from June 26 to July 9 - pdf format
Comet Machholz finder chart from July 9 to July 20 - pdf format
Comet Machholz finder chart from July 20 to July 31 - pdf format
Before perihelion Machholz 1 is visible as an early morning object in the Southern hemisphere, before becoming temporarily unobservable in mid July. After passing perihelion it will then reappear in the evening sky. For Northern hemisphere observers, the comet is unobservable before perihelion, but is viewable near the end of the month when it also appears low down in the evening sky. It remains observable although rapidly fading in brightness into August.
Comet 96P/Machholz 1 was discovered on May 12, 1986 by amateur astronomer Donald Machholz using 130mm (5.1 inch) binoculars. The comet is an unusual short-period one in that it has a highly eccentric orbit of 5.2 years. At closest approach to the Sun, Machholz 1 brushes by at a distance of only 0.12461 AU (18.64 million kms or 11.58 million miles), which is considerably closer than the planet Mercury. This is also the closest approach of all known periodic comets. On the other hand, at aphelion the comet is 5.9079 AU (884 million kms or 549 million miles) distant from the Sun, which is further than the planet Jupiter.
Comet 96P/Machholz 1 Data Table
| Date | RA (J2000) | DEC (J2000) | Est. Mag |
|---|---|---|---|
| 26 June 2012 | 4h 57m 37.5s | -9d 53m 11s | 10.4 |
| 27 June 2012 | 5h 5m 6.2s | -8d 30m 48s | 10.2 |
| 28 June 2012 | 5h 12m 33.2s | -7d 6m 37s | 10 |
| 29 June 2012 | 5h 19m 58.6s | -5d 40m 42s | 9.8 |
| 30 June 2012 | 5h 27m 22.4s | -4d 13m 6s | 9.6 |
| 1 July 2012 | 5h 34m 44.6s | -2d 43m 53s | 9.3 |
| 2 July 2012 | 5h 42m 5.8s | -1d 13m 2s | 9 |
| 3 July 2012 | 5h 49m 26.4s | 0d 19m 29s | 8.7 |
| 4 July 2012 | 5h 56m 47.2s | 1d 53m 46s | 8.4 |
| 5 July 2012 | 6h 4m 9.4s | 3d 29m 59s | 8.1 |
| 6 July 2012 | 6h 11m 34.4s | 5d 8m 23s | 7.7 |
| 7 July 2012 | 6h 19m 4.4s | 6d 49m 23s | 7.3 |
| 8 July 2012 | 6h 26m 42.4s | 8d 33m 32s | 6.8 |
| 9 July 2012 | 6h 34m 32.9s | 10d 21m 38s | 6.2 |
| 10 July 2012 | 6h 42m 42.2s | 12d 14m 49s | 5.6 |
| 11 July 2012 | 6h 51m 20s | 14d 14m 35s | 4.9 |
| 12 July 2012 | 7h 0m 41.1s | 16d 22m 49s | 4 |
| 13 July 2012 | 7h 11m 7.1s | 18d 41m 3s | 3.2 |
| 14 July 2012 | 7h 23m 3.1s | 21d 7m 49s | 2.4 |
| 15 July 2012 | 7h 36m 34.4s | 23d 33m 1s | 2.2 |
| 16 July 2012 | 7h 51m 0.8s | 25d 39m 33s | 2.7 |
| 17 July 2012 | 8h 5m 30.8s | 27d 18m 30s | 3.5 |
| 18 July 2012 | 8h 19m 43.7s | 28d 32m 14s | 4.3 |
| 19 July 2012 | 8h 33m 39.2s | 29d 26m 5s | 5.1 |
| 20 July 2012 | 8h 47m 22.4s | 30d 4m 17s | 5.8 |
| 21 July 2012 | 9h 0m 57.5s | 30d 29m 41s | 6.4 |
| 22 July 2012 | 9h 14m 26.9s | 30d 44m 10s | 6.9 |
| 23 July 2012 | 9h 27m 51.4s | 30d 48m 58s | 7.3 |
| 24 July 2012 | 9h 41m 10.8s | 30d 45m 0s | 7.7 |
| 25 July 2012 | 9h 54m 23.8s | 30d 32m 58s | 8.1 |
| 26 July 2012 | 10h 7m 28.6s | 30d 13m 28s | 8.4 |
| 27 July 2012 | 10h 20m 23.3s | 29d 47m 3s | 8.7 |
| 28 July 2012 | 10h 33m 5.5s | 29d 14m 15s | 9 |
| 29 July 2012 | 10h 45m 33.2s | 28d 35m 37s | 9.3 |
| 30 July 2012 | 10h 57m 44.1s | 27d 51m 43s | 9.5 |
| 31 July 2012 | 11h 9m 36.5s | 27d 3m 7s | 9.8 |