Comet McNaught, officially catalogued as C/2009 R, has become brighter than expected and skywatchers can now see it with the naked eye.
But there's not much time left to catch a glimpse of this unusual sight, which will disappear at the beginning of July.

It was first discovered on September 9th 2009 by the Scottish-Australian astronomer Robert McNaught, whose previous comet - nicknamed the Great Comet of 2007 - streaked across the sky in a stunning display. It is the 51st comet named after McNaught and is most easily visible in dark skies, by people who live away from urban and suburban lighting.

Comets are illuminated by the sun, which boils icy particles and dust off the comet's nucleus into a cloud of material called a head or tail form and this is reflected off sunlight. This comet's green tail looks about the same length as the width of the full moon in the sky when viewed through binoculars but it is in fact 250,000 miles across.

The is fast becoming a fairly impressive object for observers at mid northern latitudes. Visual observers have already placed the comet at mag +5.0 (Peter Horalex) which means this is technically a naked eye object!, and a very easy catch in binoculars and telescopes. The comet has a large green coma (head) with bright central condensation and a ghostly ion tail (sometimes called a gas or plasma tail) pointing directly away from the Sun for more than 1 million km through the solar system.

The coma should get brighter, and the tail longer, It already made its closest approach to Earth on June 15th (1.13 AU) before making it's closest approach to the Sun on July 2nd at 0.4 AU. The comet will be at it's best in late June when it could peak at mag +2.0, or in other words as bright as Polaris, the North Star. This peak magnitude is highly speculative at the moment because comets are notoriously unpredictable, especially 'fresh' Oort cloud visitors like this comet which have not visited our solar system before. However, a true visual magnitude between +4.0 and +2.0 seems realistic.

Path of Comet
The comet seems to have become naked visible in unpolluted skies on June 8th.

http://www.space.com/spacewatch/new-com ... 00608.html

Between June 9th and 10th McNaught passed close to the open cluster M34, then continued moving to the east. By mid June it passed through Perseus below Mirfak.

After June 15, Comet McNaught has slid lower toward the north-northeast horizon, and is now visible ? albeit with some difficulty ? both in the evening sky for a short time while just after sunset very low above the north-northwest horizon and in the morning sky just before sunrise very low above the north-northeast horizon

Near the end of the month it can be found within Auriga making a close pass by Capella in the constellation of Auriga on the 21st-22nd before we loose it within the Sun's glare in Gemini by early July. Because it has an estimated eccentricity over 1.0, suggesting a hyperbolic trajectory, it is believed C/2009 R1 will leave the Solar System permanently.

While the comet will generally be too close to the Sun for naked eye visbility by early July the one exception to this will be the total solar eclipse on July 11 in the Southern Hemisphere (visible in the South Pacific, Easter Island, and far southern Chile and Argentina]), which will allow the comet to be seen during the day. The comet is notable for its "impressive green coma and long ion tail", which spanned 5 degrees as of June 6, 2010, and its appearance has been likened to an "apple on a stick.".

Note: The best time to observe the comet is just after sunset or in the dark before sunrise.
http://en.wikipedia.org/wiki/C/2009_R1

If, we project its position on to the ecliptic the comet first appeared in the tropical sign of Taurus. The eatrliest date I can see it being spotted naked eye visible was the morning of June 6th from an astronomer in Brazil at an estimated magnitude of 5.5. Although most observers seemed to be able to observe it a few days later than this. Those that remember Comet Lulin in 2009 will recall it was ultimately a bit disappointing in naked eye terms. However, this comet looks like being considerably brighter so it should be more astrologically significant.

Like Comet Lulin this is being described as a 'green comet'. Unlike comet Lulin though comet McNaught is not close to the ecliptic. Equally, in contrast to Comet Lulin this comet is moving in zodiacal order. Once again we have a comet moving through the constellation of Perseus in the tropical sign of Taurus. Only two years ago we had another comet (Comet Holmes) that literally exploded into brightness in the constellation of Perseus ( tropical Taurus). I think that comet was was one of the astrological signs of the economic recession and other woes ahead. Another comet appearing near the fixed star Algol is another foreboding omen I am afraid. The Comet is now in the tropical sign of Gemini is likely to reach maximum magnitude in that sign. The comets astrological effects can there be associated with Taurus( sign of first visibility) and Gemini
(sign of maximum magnitude) so its astrological effects can be said to include the associations of both signs.

Summary:

-Became naked eye visible: Around 08/06/2010
-Comet is greenish in colour
-Moving in zodiacal order
-The comet is thought to be new to our solar system
-Visible in northern hemisphere at present before sunrise
-Reached closest point to earth on June 15th
-Will reach closest proximity to Sun on July 2nd (perihelion)
-First naked eye visible in tropical sign of Taurus
-Currently in tropical sign of Gemini

Here is an astronomical ephemeris in case anyone feels like converting this to zodiacal positions.

http://www.minorplanetcenter.org/iau/Ep ... 9R1_1.html

Mark

I have been trying to track down more exact information on when this comet really became naked eye visible. I found the following information on the website of the International comet authority Gary Kronk:

Observers were consistently estimating the comet's magnitude as bright than 6 as June began, indicating it was continuing to remain brighter than expected. Alexandre Amorim (Florianopolis,Brazil) saw the comet on June 6 using 10x50 binoculars and gave the magnitude as 5.5. The comet was then only 7 degrees above the horizon.

V. Ivanov (Saratov, Russia) found the comet with the naked eye on June 12. Looking through his 20-cm reflector revealed a magnitude of 5.2, a coma 3' across, and a tail 10' long.

The Space.com link above claims the comet was naked eye visible from June 8th and this what Wikipedia are citing. However, this was not based a reported naked eye sighting. The first verified naked eye sighting is by V. Ivanov (Saratov, Russia) on June 12th. As you will see from the map of the Comet's path in the previous post this locates the comet in the vicinity of the fixed star Algol in the constellation of Perseus.

Gary Kronk goes on to explain the likely magnitude of the comet until it disappears:

This comet is expected to be a bright one as June progresses. The only problem is that as it brightens it will also be sinking deeper into twilight. It will be magnitude 4 and about 20 degrees above the eastern horizon on the morning of June 15. On the morning of June 20, the comet will be about magnitude 3 and about 15 degrees above the horizon. The comet will be barely visible in the morning and evening sky on June 25, when the magnitude will be about 2.5. The altitude in the morning and evening sky might only be about 6 degrees around the time of nautical twilight. The comet will be at its brightest magnitude of about 2 during the period of June 30 to July 2. The comet would then be an evening sky object, with an altitude of about 5 degrees each day...in other words it could be very difficult to see.

http://cometography.com/lcomets/2009r1.html

Mark

Ps In a later post I will be seeking to delineate the astrological meaning of the comet using traditional techniques.

Checking out some astronomy sites it seems a lot of astronomers are having difficulty catching this comet. Although it is within visual magnitude the fact it is mid summer means there are only a few hours of real darkness before sunrise. Secondly, the comet is fairly low in the sky. Thirdly. we have the problem here in the UK and elsewhere of cloud cover. Thats not even considering those of us cursed by heavily light polluted urban skies.

The comet is near the bright yellowish star Capella in the constellation of Auriga tonight. Its not going to look much more than a small fuzzy star without binoculars. This is no Hale-Bopp!

I suggest using the W shaped constellation Cassiopeia as a point of reference and scanning to its extreme lower left. Capella is visually the most yellowish looking star in the sky so it should stand out . Good luck skywatchers!

Ps that means the comet has reached around 21-22 Gemini in the tropical zodiac so you can add that to your list of transits if you have any planets/angles in late Gemini!

I feel I owe members an update and explanation here as I previously suggested I would be doing a delineation of this comet. On balance I have decided not to do this. My reasons for not doing this are as follows:

1 The comet was something of a disappointment for most sky watchers. It doesn't seem to have got above 5th-6th magnitude. That is just on the threshold of visual magnitude. Astrologically, the brighter a comet is the more astrologically significant it is. On that basis this comet is of less astrological influence than some other bright naked eye comet we have seen in the last few years. Having said that it was probably as bright as comet Lulin which caused a flurry of interest here on the forum in early 2009. This one never seemed to inspire similar interest. Maybe it was the name, the poor observing conditions in many locations, the holiday season or astrological interest being more focused on things like the World Cup!

2 The comet was low in the sky during much of the time making observation difficult.

3 As it was midsummer there were few hours of darkness and in northern latitudes (Scotland, Scandanavia etc) it was never dark enough to realistically comet spot at this time of year as the Sun never dips that far below the horizon.

4 That is not including the normal curses of observers such as cloud cover and the light pollution.

5 Another astrological isssue I had was the disputed dates for visibility. The most solid seemed to be June 12th. However, that date coincided with a lunation. It was therefore unclear whether to use this lunation or the one preceding this.

In short despite the flurry of interest in the astronomical press this comet was an anti-climax. Its often difficult to predict how bright a particular passing of a comet might be. Sometimes they exceed all expectations while other times they come to nothing. Unlike the predictable cycles of planets comets are by nature hard to predict in terms of visual magnitude. As David Levy an astronomer who is an authority on comets states:

''Comets are like cats; they have tails, and they do precisely what they want."'


This comet was a particuarly tricky customer as astronomers believe it was its first (and likely last!) passage around our Sun. In a sense I dont really feel this low key comet deserves the attention of a long piece devoted to its delineation. However, a new bright comet could appear in the sky anytime. If that happens people will be scrambling here to interpret its meaning. When it does its useful to have some astrological guidelines. However, I have decided this will work better as an article here than a post buried in the forum. Some time back Deb invited me write a piece on this topic. I have decided to belatedly follow up her offer by putting together a piece summarising traditional techniques on comets for members.

Thanks

Mark