New Comet Now Visible to Naked Eye

Yahoo ^ | December 8, 2004 | Robert Roy Rritt

[Right Wing Professor]

A comet discovered earlier this year has now moved close enough to be visible without binoculars or telescopes by experienced observers under dark skies. It is expected to put on a modest show this month and into January.

Comet Machholz will be at its closest to Earth Jan. 5-6, 2005, when it will be 32 million miles (51 million kilometers) away.

People with dark rural skies and a good map should be able to find it on Moon-free nights now into January.

Backyard astronomers have been watching Machholz for months through telescopes. It was spotted by naked-eye observers for the first time about three weeks ago from the Southern Hemisphere, said Donald Machholz, who discovered the frozen chunk of rock and ice in August.

"I saw it last night for the first time with the naked eye," Machholz told SPACE.com Friday.

Comets are made of rocky material and icy mixtures of water and various other chemicals. As a comet approaches the Sun, the surface is heated and essentially boils off. Scientists call the process sublimation. The gas and dust creates a head, also called a coma, and sometimes a tail. Sunlight reflects off the material, making some comets visible from Earth.

Comet Machholz, officially named c/2004 Q2, is not expected to produce the sort of spectacular display put on by comet Hale-Bopp in 1997 or the periodically stunning Halley's comet.

Astronomers cannot say exactly how bright Machholz will get, because it is notoriously difficult to predict the behavior of comets making their first observed close trip around the Sun. Scientists don't fully understand the composition of comets, nor their variety, so they don't know how much stuff will sublimate nor how fast.

Machholz is expected to reach magnitude 4.0, based on an early estimate. On this astronomers' scale, smaller numbers represent brighter objects. The dimmest things visible under perfectly dark skies are around magnitude 6.5. The brightest star, Sirius, is magnitude minus 1.42.

Recent observations suggest Machholz will do at least as well as first predicted.

"The comet is doing better than expected and is about 0.5 magnitudes brighter than expected," Machholz said. "So it will probably get brighter than the Andromeda Galaxy, brighter than magnitude 4.0."

The Andromeda Galaxy is the furthest object visible to the unaided human eye under dark skies. It is a magnitude 3.4 object.

If the comet were to become roughly magnitude 3.0, it would still appear common among the sea of stars available to dark-sky observers. City and suburban dwellers would likely not find it without optical aid. In either case, binoculars or a small telescope might reveal the comet as more of a fuzzy patch, and if it develops a significant tail, that could be visible too.

Machholz, who has found nine other comets, suggests looking for his latest discovery when the Moon is out of the picture, such as around Dec. 11 when it will be at its New phase.

"The comet can still be seen when the Moon is out, but it will be difficult," he said by email. "Use binoculars or a wide-field (low power) telescope, and/or get to a dark site."

The comet is low on the horizon now, where the atmosphere makes for poor viewing. By early January, the comet will be much higher in the sky, improving viewing conditions.

I haven't yet found a decent online map of its current and predicted positions; if I can't find one tomorrow, I'll draw one and post it.

[JeffersonRepublic.com]

Ping... waiting for a clear sky

[FreedomCalls]

Comet Machholz

Coarse finder chart (60° field-of-view, stars to mag. 6.5)

Fine finder chart (5° field-of-view, stars to mag. 9.0)

All data valid for local time 06:09:45, 09 Dec (UTC 05:09:45, 09 Dec)

Geocentric Data
Right Ascension (J2000):	4h 41m 19.6s
Declination (J2000):	-22° 28' 26"
Constellation:	Eridanus
Magnitude:	5.6
Distance from Earth:	0.5269 AU
Light time:	263 seconds

Heliocentric Data
Distance from Sun:	1.4045 AU
Perihelion:	1.2051 AU (24-Jan-2005)
Aphelion:	4,838.51 AU
Period:	119,039.8 years
Eccentricity:	0.999502
Inclination to ecliptic:	38.589°
Longitude of ascending node:	93.627°
Argument of perihelion:	19.502°

[concentric circles]

From Sky and Telescope: Comet symbols show it's position at
0:00 Universal Time on the dates indicated; which is on the
evening of the previous date local time in North America.

[My2Cents]

[Eastbound]

Found it. I think. It's the only fuzzy object in the area. Pretty big through the binocs. Using a 12x50 zoom at wide angle. Seems a little on top of the line you drew. Is that correct?

[My2Cents]

Hope it's clear here on Jan. 5th. It should be easy to find, just below the Pleiades.

[dc-zoo]

Naked Eye.. sounds a bit Ob Seen.

[Kirkwood]

Graat! Ill be high up in the mountains around Jan 5 and 6 and hopefully will have clear skies.

[Eastbound]

Oops! My mistake. I don't have zoom, so just using the 12. (272 feet @ 1000 yards). Will try to take a picture with my Z1 digital.

[Right Wing Professor]

Thanks. I've put its current (12/8/04) position on the map, as a yellow dot; The yellow arrow points to it. It's going to inch up slowly each night.

[Brad’s Gramma]

So! I went outside as directed....I saw two planes coming in to John Wayne...and the neighbors have THE nicest rooftop decorations.

Other than that....a wholelotta clouds. :)

[Right Wing Professor]

That's right where I saw it. Thanks.

[Right Wing Professor]

Seems a little on top of the line you drew. Is that correct?

Hard to say what's a straight line on a sphere. :-) I gave the best estimate I could using a ruler and a star atlas.

[Right Wing Professor]

Could you put that into laymans (farm people) terms please?

Hey, I live on a farm too.

It's low in the south. I've you've got really good eyes and you live away from the city, you might see it as a fuzzy patch to the south about midnight, if you let your eyes get used to the darkness for a half hour. If you have any kind of binoculars or a spotting scope, it should show up pretty clear. It'll be getting brighter and higher in the sky for the next month; I'd estimate it'll be easily visible to the naked eye by early January.

[Eska]

Live up on the yukon, real dark skys. Cold & clear minus 32. I noticed something yellower & brighter to the SE on horizon; different than everything else with bino's. Or is it straight south on horizon?

[Angry Enough]

Is this any relation to Comet LouHolz?

[El Gato]

Cloudy here, darnit!

Here too. If I'd just known last night I could have finally used my new telescope, which I've had for about 6 months (It was a gift). I'm in a fairly dark sky spot, so with the 'scope or my 7X50s, I should be able to see it pretty well

.....

Just went out to check. It's cleared up since sunset! However, I've recently moved and just discovered that I haven't a clue where my binoculars are. :( Oh, well, I'll set up the 'scope tommorrow and take a look.

[NotJustAnotherPrettyFace]

Thanks for the viewing information. My husband is an excellent amateur astronomer. We have an 8" Celestron in a trunk which we'll have to get out and use to find this comet, of course. :-)

[apastron]

[Eastbound]

Going to have to try it again tomorrow. Here's my first attempt. At least I think I'm in the right area but need to bracket a few for longer exposure. Thanks for the tip, RWP.

CLICK!