Comet LINEAR T7 on Monday Evening

[Dave Mitsky]

I had the opportunity to observe Comet LINEAR T7 from the ASH Naylor Observatory near Lewisberry, Pennsylvania, on Monday evening from 0:25 to ~1:10 UT (2004/2/17). The skies were initially fairly clear and transparent but high clouds eventually entered the scene. The tail that I had first seen two Sundays ago was markedly longer and at times I thought I saw a bifurcation. A stellar pseudonucleus seemed to be present.

The 17" f/15 classical Cassegrain was used at magnifications of 118, 144, 162, 202, 231, and 259x with 202x providing the best view of the comet.

Dave Mitsky

[ebbixx]

Originally posted by Dave Mitsky@Feb 18 2004, 05:35 AM
I had the opportunity to observe Comet LINEAR T7 from the ASH Naylor Observatory near Lewisberry, Pennsylvania, on Monday evening from 0:25 to ~1:10 UT (2004/2/17).

Planning to look for this in the next few nights as it brightens. Tomorrow should be clear here, for a change.

Speaking of comets, do you know whether it's true that NEAT (C/2001 Q4) is likely to get quite bright (and visible at night above horizon) on or after May 4 (2004)? My charting program -- which I don't entirely trust -- suggest an apparent 1st mag.

Also, while apparently dimming to 1.4 mag, on May 14 it appears it will line up Venus, Mars, Saturn and Jupiter -- occupying a largish gap in Cancer between Saturn and Jupiter. Should be an interesting image, especially if the magnitude number is true.

My question, is my software way off on the predicted magnitude? (A different menu in the same program gives the magnitude as 7, not 1 or 1.5)

Seems I would have heard something about an event like this. Then again, maybe I just missed it. I checked the JPL comet site, and couldn't seem to find anything to corroborate this, aside from noting that the comet will be in the visible range for the immediate future. On May 4th my program states distance from Earth at 0.3255 AU, and solar distance at 0.9808 AU.

[Dave Mitsky]

The smart money always bets that almost every comet that attracts the attention of the popular media will be a disappointment to the average person. On average one bright comet occurs about every 20 years. Of course, the late 1990's brought us the peak of two great comets, Hyakutake and Hale-Bopp, in about a year's time.

The latest estimates of maximum magnitude that I've seen for these two comets are 2.5 for NEAT Q4 and 0.8 for LINEAR T7, both of which are more than perfectly respectable. Unfortunately, T7 will be low in the sky for most northern hemisphere observers. The fact that two bright comets will be visible at the same time is certainly a bit a of a novelty.

See http://www.skyrover.net/notebook/resources/finder.asp for simplified finder charts of the two comets in May and June.

Dave Mitsky

[DippyHippy]

Is it just me, or do all comets seem to be poorly placed for northern hemisphere observers when they're at their brightest?? :(

[Dave Mitsky]

Originally posted by DippyHippy@Feb 25 2004, 03:02 AM
Is it just me, or do all comets seem to be poorly placed for northern hemisphere observers when they're at their brightest?? :(
Comet Hyakutake at its peak was about as good as a comet can get for northern observers. It was passed fairly close to the north celestial pole. When it was close to the Earth the tail was simply incredible when seen from a dark site after moonset.

Comet Hale-Bopp was pretty well placed for us as well.

Dave Mitsky

[DippyHippy]

Yeah, I remember Hale-Bopp - who doesn't? Fantastic! But even then, I seem to remember it being best seen from the southern hemisphere when it was at it's closest... I dunno, I'm probably wrong LOL

[ebbixx]

Originally posted by DippyHippy@Feb 25 2004, 03:02 AM
Is it just me, or do all comets seem to be poorly placed for northern hemisphere observers when they're at their brightest?? :(
Comets (in general) pose the same problems (or worse, considering their highly elliptical orbits) for optimal viewing as (sometimes) Venus and (nearly always) Mercury.

Hardly surprising then that there is usually some struggle in finding a time when both (a) the sky will be dark; and (B) the comet will appear far enough above the horizon (in either hemisphere) to overcome the challenges of atmospheric distortion/filtering and twilight "light pollution."

I realize this is stating the obvious. :) My guess, though, is that for a random sampling of near-Earth passes, neither hemisphere has an actual advantage. So far as I've been able to tell, the Northern Hemi. will have the better views of NEAT Q4, whatever its apparent magnitude turns out to be, coming this May.