C / 2006 P1 (McNaught)

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C / 2006 P1 (McNaught) [i]
Comet McNaught
Properties of the orbit ( animation )
Orbit type hyperbolic
Numerical eccentricity 1.00003
Perihelion 0.171 AU
Inclination of the orbit plane 77.828 °
Perihelion January 12, 2007
Orbital velocity in the perihelion 101.9 km / s
Explorer RH McNaught
Date of discovery August 7, 2006
Older name -
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . Please also note the note on comet articles .

C / 2006 P1 (McNaught) is a comet that was discovered on August 7, 2006 by the Australian Robert McNaught . The comet became the brightest comet since Ikeya-Seki in 1965 in January 2007 and was the first comet since 1976 that could be seen in the daytime sky with the naked eye .


Robert McNaught discovered the comet with a 50 cm Schmidt telescope as part of the Siding Spring Survey . The night sky is regularly monitored for new asteroids and comets. It was McNaught's 31st comet discovery.


The comet passed the Sun on January 12, 2007 at a distance of only 0.17 AU . The point closest to the Sun ( perihelion ) was still within Mercury's orbit. The closest to earth was reached on January 15, 2007 with 0.81 AU.

Observation conditions

From December 2006 to the third week of January 2007, the comet was only a small angular distance away from the Sun, which is why it was very difficult to observe at dusk.

In the northern hemisphere, the best visibility conditions were in the week before perihelion . The comet could be seen both at dusk and at dawn. Up to and including January 13th, he was still clearly visible in Central Europe at dusk. Since the comet was meanwhile south of the sun, for observers in the northern hemisphere it set before the sun and only after the sun rose, which is why observations in the evening or morning sky were no longer possible. On January 13, the comet in Central Europe could be seen with the naked eye even in the daytime sky . On January 14th, there were isolated telescopic sightings in the daytime sky. Actually, the comet could no longer be seen in the northern hemisphere afterwards because it was too far south. This only applied to the comet's head. After perihelion, the tail became so long that, surprisingly, images of the outermost extensions of the comet's tail were taken from the northern hemisphere on January 17th. On January 20th, the tail structures were also photographed from Germany and Austria. They could be seen about 1-2 hours after sunset in a westerly direction, but extremely faint.

The comet appearance in the southern hemisphere in the two weeks after perihelion was even more spectacular than in the northern hemisphere. The comet formed a broad and about 40 ° long tail. In contrast to the observation conditions in the northern hemisphere, which were severely affected by twilight, the comet in the southern hemisphere could be seen in a much darker sky, as the angular distance between the comet and the sun had increased rapidly after perihelion. In the further course the comet was also visible there in the dark night sky and observable all night. On February 1, he could still be seen bare-eyed in the night sky in the southern hemisphere .

Brightness development

Comet McNaught, taken in the daytime sky on January 13, 2007

The comet was visible to the naked eye on January 5th, 2007 with a good horizon in the twilight sky. Its brightness at that time was about 1 mag . On January 6th, the brightness reached 0 mag . On January 7th, the first telescopic photograph of the comet was taken during the day. On January 8th the brightness was −1 mag , on January 10th −2 mag and on January 12th over −3 mag . On the 12th, the comet was first seen with the naked eye in the daytime sky. The observation was made 15 minutes before sunset under a very clear sky on a 1250 m high mountain. On January 13th, the comet was seen by several observers in southern Germany, Austria and Switzerland at noon and in the afternoon in the daytime sky , which was deep blue and exceptionally transparent. The brightness of the comet on this day was about −5 mag (significantly brighter than Venus). Also on January 14th the comet was seen with the naked eye in the daytime sky, because the comet reached its greatest brightness with about -5.5 mag . On January 15th the brightness had dropped to about −4 mag and there were only a few open-eyed sightings in the daytime sky. On January 1st it was just under −3 mag . Despite decreasing overall brightness, the comet's appearance in the southern hemisphere got better from evening to evening, as in return the angular distance to the sun has improved. On January 18, the comet was an unmistakable object in the evening sky. After that, the brightness continued to decrease and was +3 mag on February 1st . The comet was still visible to the naked eye in the southern hemisphere until about February 5, after which it could be observed with binoculars for a few days .

Observation from space

Tail of McNaught recorded on January 11th by STEREO-B

From January 12 to 16, McNaught scanned the field of view of the coronograph LASCO C3 of the SOHO space observatory . It was the brightest comet that was registered with this instrument. The brightness was so strong that the picture was partially outshone. In addition, the STEREO-B space probe transmitted images of the comet to Earth. For the first time, images showed the tail of the comet in its full extent.

See also

Web links

Commons : Comet C / 2006 P1 (McNaught)  - Collection of images, videos and audio files