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ngc3314
2007-Oct-29, 03:18 AM
Now I have three successive nights to compare. Eventually we should see the debris stretch roughly along the orbit as the stuff ejected forwards moves away along a higher/slower path and the stuff ejected backwards does the opposite. Shuttle water dumps do it, tidally disrupted globular clusters do it, unsuspecting dwarf galaxies do it - now here it is before our eyes. But not this week... (If it weren't getting late and me having to be up in six hours, I'd put some numbers to that. Later. Celestial mechanics are free to chime in.)

Tucson_Tim
2007-Oct-29, 04:12 PM
Nice progression. I've been curious if it will develop a tail but I guess it's too far from the sun???

dhd40
2007-Oct-29, 09:46 PM
Nice progression. I've been curious if it will develop a tail but I guess it's too far from the sun???

I was also wondering about this. Possible explanation:

http://www.skyandtelescope.com/observing/home/10775326.html


Future prospects. The comet is likely to stay bright for many days or weeks. The yellow color is dust reflecting sunlight, as confirmed by the spectra that have been taken. Dust is what keeps a comet bright — as opposed to gas (comet gas is green and blue), which blows away quickly in the solar wind. This comet won't fade out soon.

Any tail will probably be short and stubby when, or if, it forms. The tail should be pointing nearly away from us in space — we're looking down its length — since the comet is nearly on the opposite side of Earth from the Sun. From the comet's viewpoint, the Earth and Sun are only about 15° apart, and this phase angle will stay small for many months. So we'll keep looking down the tail.

stargazer_7000
2007-Oct-30, 10:09 AM
nice series - ngc3314...

JAICOA
2007-Oct-30, 02:36 PM
Very nice photos NGC1314, What were your equipment used and dates?. Welldone and Clear Skies

ngc3314
2007-Oct-31, 02:28 AM
Very nice photos NGC1314, What were your equipment used and dates?. Welldone and Clear Skies


The weather is staying good, so I'm still at it. (0.4m Ritchey-Chretien reflector at the University of Alabama observatory (http://www.astr.ua.edu/keel/ua16inch.html), SBIG STL-6303E camera, R filter, exposures 10-300 seconds lengthening as the main dust puff expands). Here's a series from Oct 26-30 local time. I suspect that the symmetry of the main circular outburst is breaking with the outline fuzzing out on one side. Each image section is about 15 arcminutes N-S (out of the 20x30-arcminute field of the chip). These are quick-and-dirty logarithmic displays, with only dark subtraction done beforehand (mostly because my schedule has been hectic this week, but at least the bits are on disk for more complete exploitation later).

ngc3314
2007-Oct-31, 02:31 AM
Very nice photos NGC1314, What were your equipment used and dates?. Welldone and Clear Skies


The weather is staying good, so I'm still at it. (0.4m Ritchey-Chretien reflector at the University of Alabama observatory (http://www.astr.ua.edu/keel/ua16inch.html), SBIG STL-6303E camera, R filter, exposures 10-300 seconds lengthening as the main dust puff expands). Here's a series from Oct 26-30 local time (between 0200-0400 UT each date, which will be one later than local). I suspect that the symmetry of the main circular outburst is breaking with the outline fuzzing out on one side. Each image section is about 15 arcminutes N-S (out of the 20x30-arcminute field of the chip). These are quick-and-dirty logarithmic displays, with only dark subtraction done beforehand (mostly because my schedule has been hectic this week, but at least the bits are on disk).

(Edit: oops, I tried to add the timing information and ended up with a new post. Apologies.)

Whirlpool
2007-Oct-31, 11:14 AM
All I can say is ... WOW!



;)

JAICOA
2007-Oct-31, 07:03 PM
Great Images! NGC3314, And thanks for the info. Clear Skies

winensky
2007-Nov-01, 12:20 AM
I am amazed at the continued brightness. As the original cone of ejecta, (which we are seeing from 'behind'),expands and becomes more diffuse one might expect a brief bright burst then gradual dimming but the shell like structure of the ejecta cloud seems to indicate further disturbances at the core. Thanks for the wonderful series.

Kind regards
Matt

Dave J
2007-Nov-01, 03:23 AM
I got a look at it through my old C-8 tonight, despite all the porch lights for Halloween, it was clearly naked eye visible, and very impressive through the scope. Some of the later trick or treaters got a bonus through the eyepiece.

Phil in England
2007-Nov-01, 09:15 AM
Wouldn't an outburst/superoutburst/impact/de-lamination etc. have altered Holmes' trajectory ?

ngc3314
2007-Nov-01, 01:52 PM
Can't help myself. Must keep imaging...

(Oct 27 - Nov 1, UT).

mahesh
2007-Nov-01, 02:44 PM
Can't help myself. Must keep imaging...

(Oct 27 - Nov 1, UT).

:):) Bravo :):)

keep 'em coming....

many thanks for sharing

George
2007-Nov-01, 03:41 PM
Can't help myself. Must keep imaging...

(Oct 27 - Nov 1, UT).
Good, don't stop. These are simply marvelous! :clap: [Added: We'll make sure someone gets food to you. ;)]

Here (http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=17p&orb=1) is the JPL orbital plot and data which shows much. Using their 3d view, it appears the Earth is in a position that would minimize the apparent positions of both the inward and outward "puffs". [Earth's orbital direction is reducing our view of it, but we are in a position to see it, of course.]

Casus_belli
2007-Nov-01, 04:37 PM
Yeah keep them comming. Its been cloudy here for the past three days and your photos are keeping me abreast of the situation

George
2007-Nov-01, 06:05 PM
The weather is staying good, so I'm still at it. (0.4m Ritchey-Chretien reflector at the University of Alabama observatory (http://www.astr.ua.edu/keel/ua16inch.html), SBIG STL-6303E camera, R filter, exposures 10-300 seconds lengthening as the main dust puff expands). Very nice CCD unit (http://www.sbig.com/sbwhtmls/online.htm)! It seems to favor yellow objects, too.

ngc3314
2007-Nov-02, 12:35 PM
Can't fit them on one row any more, now spanning the nights of Oct. 26 - Nov. 1. Who'd have expected a full week of clear weather around here?

Tonight's imaging will be interesting - the athletic department asserts ownership of all nearby parking starting at 1700 the night before any home football game. Early in the night, though, we have a public event scheduled about 20 miles distant at a darkish site, which should acquaint many people with this eerie sight. The Birmingham newspaper ran the first four images on their front page today, which should be good for an extra crowd.

Sorry about the default orientation (south up, east left). That will get fixed along with flat fielding and stacking One of These Days. Or nights.

Moseley
2007-Nov-02, 12:47 PM
More wonderful shots, thank you.

George
2007-Nov-02, 03:17 PM
The Birmingham newspaper ran the first four images on their front page today, which should be good for an extra crowd.
:clap: The article (http://www.al.com/news/birminghamnews/index.ssf?/base/news/119399189219880.xml&coll=2) is great, too! Very nice. Was the comet a good or bad omen for your son's football game? :)

Tucson_Tim
2007-Nov-02, 03:54 PM
Can't fit them on one row any more, now spanning the nights of Oct. 26 - Nov. 1. Who'd have expected a full week of clear weather around here?


Wonderful progression! Thanks for posting.

ngc3314
2007-Nov-03, 02:00 PM
Eight in a row! I make the coma now about 16 arcminutes in diameter, so after another couple of nights it will take multiple exposures to get the whole thing. Visually the bright inner coma is getting more elongated. Lots of visitors at our public event last night went with the "jellyfish" description.

Gsquare
2007-Nov-03, 03:25 PM
Eight in a row! I make the coma now about 16 arcminutes in diameter, so after another couple of nights it will take multiple exposures to get the whole thing. Visually the bright inner coma is getting more elongated. Lots of visitors at our public event last night went with the "jellyfish" description.


This is quite an event.....( great pics, )......I read recently that the expansion is now about the size of Jupiter....Yikes, is that possible?....no wonder it is so bright.

Tucson_Tim
2007-Nov-03, 03:29 PM
This is quite an event.....( great pics, )......I read recently that the expansion is now about the size of Jupiter....Yikes, is that possible?....no wonder it is so bright.

I read on the SpaceWeather site a day or two ago that it was already several times the size of Jupiter (but I can't find the quote there now :confused:)

http://www.spaceweather.com/

dhd40
2007-Nov-03, 03:44 PM
Has it become generally accepted that holme´s tail isn´t visible due to our direction of view? (I.e., the tail is there but hidden from view by the coma)
Or are there other explanations for the missing tail?

Gsquare
2007-Nov-03, 04:06 PM
I read on the SpaceWeather site a day or two ago that it was already several times the size of Jupiter (but I can't find the quote there now :confused:)

http://www.spaceweather.com/


Thanks, Tim; I like ngc3314"s progression, but here's a close up from Spaceweather.com....Whoa! :D

http://www.spaceweather.com/comets/holmes/02nov07/Sebastian-Voltmer2.jpg

Hit the enlargement symbol and you can see some structure in the ejecta near the nucleus.

G^2

JAICOA
2007-Nov-03, 05:42 PM
A beautiful serial set of the comet!, NGC3314 may you have clear skies. Keep on tracking.

winensky
2007-Nov-04, 09:29 AM
A wonderful set. You have created a great study. And now as our orbital paths start to diverge, the halo is taking on a diffuse edge. We may yet see a 'tail' of sorts.

Kind regards
Matt

ngc3314
2007-Nov-05, 02:30 AM
Ten in a row, October 26 to November 4! The whole coma still fits on our detector, but I'll have to reprocess to get them in such a nice display with a wider field. As a special treat George is in town assisting tonight! He was just making some heliochromological comment about whether I should refer to the color of reflected sunlight as "yellow".

Jens
2007-Nov-05, 07:57 AM
Is the magnitude still something like 2.5? I assume that it's still just about as easy to see as it was a week ago.

Swift
2007-Nov-05, 08:18 PM
Is the magnitude still something like 2.5? I assume that it's still just about as easy to see as it was a week ago.
To my eyeballs, it looks a little dimmer to the naked eye, but it is still easily a naked eye object, even with my mediocre suburban skies. It also looks a little dimmer to me in the binocs, but even in those you can tell it is larger. I have wondered if it looks dimmer because it is spread out over a bigger volume?