Comet McNaught

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For other uses, see Comet McNaught (disambiguation).

**C/2006 P1 (McNaught)**
Discovery

Discovery date:	August 7, 2006
Alternate designations:	C/2006 P1, Comet McNaught, Great Comet of 2007
Orbital characteristics ^A
Epoch:	2454113.2961 (January 20, 2007)
Perihelion distance:	0.17075400 AU 25,544,000 km
Semi-major axis:	-5681.10388683 AU
Eccentricity:	1.00003006
Inclination:	77.82768004°
Last perihelion:	January 12, 2007
Next perihelion (predicted):	N/A

Comet McNaught, the brightest comet in over 40 years, also known as the Great Comet of 2007 and given the designation C/2006 P1, is a non-periodic comet discovered on August 7, 2006 by British-Australian astronomer Robert H. McNaught.^[1] It made perihelion on January 12, 2007, and became easily visible to the naked eye for observers in the Southern Hemisphere.

1 History
2 Current viewing
3 Image gallery
4 References and footnotes
5 External links

[edit] History

Soon after confirmation of the discovery, Southern hemisphere observers began following the comet to refine the description of its orbit. From August through November 2006, the comet was imaged and tracked as it moved through Ophiuchus and Scorpius, giving an estimated brightness as high as magnitude +9, still too dim to be seen with the unaided eye.^[2] Then, for most of December, the comet was lost in the glare of the sun.

Upon recovery in late December, it became apparent that the comet was brightening rapidly, reaching naked-eye visibility in early January 2007. It was visible in the northern hemisphere near Venus, in Sagittarius and surrounding constellations, until about January 13. Perihelion was January 12 at a distance of 0.17 AU.^[3] This was close enough to the Sun to be observed by the space-based Solar and Heliospheric Observatory (SOHO). The comet entered SOHO's LASCO C3 camera's field of view on January 12, and was viewable on the web in near real-time. The comet exited SOHO's field of view on January 16. Due to its proximity to the sun, the Northern Hemisphere ground-based viewers had a short window for viewing, and the comet could be spotted only during bright twilight, immediately after sunset.

The orbit (green) of Comet McNaught on January 14, 2007 and the four orbits (orange) of the inner planets. Earth is the blue dot on the right. The Milky Way can be seen on the lower left. The comet orbits clockwise.

As it reached perihelion on January 12, it became the brightest comet since Comet Ikeya-Seki in 1965.^[4] The comet was dubbed the Great Comet of 2007 by Space.com.^[5] On January 13 and 14, 2007, the comet attained an estimated maximum apparent magnitude of -6.0, as reported by several observers in the Northern hemisphere.^[3]

Comet McNaught in broad daylight while it was visible by naked eye. Taken on January 13 at 14:00 UTC in Gais, Switzerland.

The comet was visible in daylight about 5°- 10° southeast of the sun from January 12 to 14, with a peak brightness of magnitude -5.5.^[6] Perigee (closest approach to the Earth) was January 15, 2007, at a distance of 0.82 AU.^[7]

After passing the sun, McNaught became visible in the Southern hemisphere. In Australia, according to Siding Spring Observatory at Coonabarabran, where the comet was discovered, it was to have reached its theoretical peak in brightness on Sunday January 14 just after sunset,^[8] when it would have been visible for 23 minutes. On January 15 the comet was observed at Perth Observatory with an estimated apparent magnitude of -4.0.^[3]

[edit] Current viewing

The comet has faded to about magnitude +10. It remains partially visible as a faint telescopic object to some Southern Hemisphere observers in both the morning and evening sky, near the constellation Tucana.^[9]

[edit] Image gallery

Images of Comet McNaught in January 2007
Over Iceland on 9 January	Just after sunset from Perth, Western Australia on 16 January	Over Perth, Western Australia at 9 p.m. on 17 January	Seen from South Beach, Fremantle, Western Australia on 17 January. The lights at the bottom are navigation lights in Gage Roads.
Setting behind the Andes, at Bariloche, Argentina, on 17 January	18 January from Pukekohe, New Zealand	19 January from La Perouse, Sydney, Australia	From Signal Hill, Cape Town on 19 January. The silhouette of Lion's Head is visible on the left, while on the right Venus sets over the Atlantic Ocean.
20 January from Lawlers,Western Australia	Villa Alemana Region of Valparaiso, Chile on 20 January	from Red Hill, Canberra on 21 January