You would think Space Weather wouldn't forget seeing this comet before. This isn't McNaughts first visit. First discovered at the end of 2006, the comet made a beautiful pass in 2007. Mostly visible from the southern hemisphere.
May 31st will find McNaught, now hopefully 6th or 7th magnitude, passing 2½° southeast of the 2nd-magnitude star Beta Andromedae. At the beginning of astronomical twilight it’s a respectable 20° up as seen by observers at 40° north latitude. But the waning gibbous Moon will brighten the sky.
The June comet crosses Perseus, low just before dawn, when at its best in June. Click image for larger, printable chart.
Sky & TelescopeOn the morning of June 5th the comet skims just north of the large, loose open cluster NGC 752. On June 6th and 7th it’s within about 2° of the 2nd-magnitude double star Gamma Andromedae. The Moon is much thinner then, but also closer to the comet.
Mid-June is when Comet McNaught should be most interesting, offering the best compromise between its increasing brightness and its decreasing altitude at the start of dawn. Moreover, the sky will be free of moonlight.
The helpful conjunctions continue as the comet passes about 1° north of the open cluster M34 in Perseus on the morning of June 10th, and 3° south of 1.8-magnitude Mirfak (Alpha Persei) on the 13th. It’s still about 15° high in the northeast as the sky starts to grow light on June 15th, but it appears roughly 1° lower every day after that. The comet passes zero-magnitude Capella on the 21st, and it’s very low by the 24th, when it passes 2nd-magnitude Beta Aurigae.
By now Comet McNaught may be as bright as 4th or 5th magnitude, but moonlight is returning.
http://www.skyandtelescope.com/observing/highlights/94277259.html
The comet will be lost to view by June’s end — just before it reaches perihelion on July 2nd, 0.405 astronomical unit from the Sun. It remains far from Earth throughout this apparition, never venturing closer than 1.135 a.u. (in mid-June). After perihelion it will fade rapidly as it heads to the far-southern sky.
I agree with you . . . that was my first reaction to this story.
Apparently the comet passed by the earth in 2007 along what was originally described as a hyperbolic path -- meaning it would make its way through the solar system and never return. Somewhere along the way its trajectory was altered and it ended up in an elliptical orbit that is typical of a periodic comet. So now it is back three years later. That's a very short period for a comet.
The 2007 visit was spectacular, but didn't get a lot of attention here in the U.S. because it was mainly visible from the Southern Hemisphere. It was clearly visible during daylight hours for a while, and some of the most spectacular images I've seen are the ones that show the long wisp of the comet's tail rising from the horizon even as the head was no longer in view above the horizon.
