Huge comet outburst reported, 17P/Holmes |
Huge comet outburst reported, 17P/Holmes |
Guest_Sunspot_* |
Oct 28 2007, 08:02 PM
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#46
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Guests |
The sky has finally cleared and i've just come in from observing it with my 4.5" reflector. It does look exactly like some of the pictures i've seen. A large spherical coma with a slightly brighter annulus. Star like nucleus with a brighter patch to one side.
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Oct 28 2007, 08:17 PM
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#47
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
... and now it's cr**ping it down. Again.
(noise of fingers drumming on desktop) Going to take up cloud-spotting if this goes on, I swear... -------------------- |
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Oct 28 2007, 08:25 PM
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#48
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Junior Member Group: Members Posts: 98 Joined: 29-July 05 From: Amsterdam, NL Member No.: 448 |
A figure of say 300 m/s sounds more plausible. I agree. Rough calculations for me yield velocities of ~360m/s and this number is more or less constant for the last three days (to within error). I also searched the literature and found nothing in the range of 2.4km/s for comet emission velocities. Most were at or less than 0.5km/s and this also seems to be the norm for comet gas emissions. What still strikes me with this comet is that the expanding cloud is spherical in shape--the gas and dust seems to be moving from the source outward largely uninhibited. Perhaps naively, I might have expected a more directed emission of the volatiles. Kohoutek 0.5km/s Hale-Bopp 0.4km/s LINEAR 1999 S4 0.5km/s Tempel 1 >0.16km/s (projected velocity) Anyway, more rain tonight... |
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Oct 28 2007, 08:34 PM
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#49
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Nice & clear here (finally; the damn smoke is abating as the fires come under control). Gonna give it a shot tonight naked-eye from the roof of my apartment complex. Would drive out of town, but gotta work tomorrow & as anyone who's ever been in LA for any amount of time knows you can get stuck in traffic at the drop of a hat in either direction...
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Oct 28 2007, 08:47 PM
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#50
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
Within the last hour skies have cleared beautifully over North Wales. The comet is in full view now, and so bright that the full moonlight hardly matters. It is much bigger and fuzzier than when I saw it first and noticeably brighter too relative to the stars of Perseus. (I hope the same happens in Cumbria, Stu. Snowdonia and Cumbria often get the same weather at about the same time so keep looking out!)
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Guest_Sunspot_* |
Oct 28 2007, 08:47 PM
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#51
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Guests |
The Moon is VERY bright tonight and not too far off in the sky, lets hope the comet maintains it's brightness for a few more days.
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Oct 28 2007, 10:00 PM
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#52
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
Yes!! Finally!!! The cloud cleared around 9pm and I went outside to see if I could see Perseus - and noticed right away that there was something wrong with its shape, an extra blobby "something" that isn't usually there.... Lifted the binoculars -
GOOD GRIEF!!! Someone moved the globular cluster M13 closer to Earth! It was **ridiculous**! Like a new gas giant planet had somehow appeared in the solar system. Inside for the telescope, swung it around... Oh. My. Word. Look at that... it filled a quarter of the eyepiece at 26x magnification, with a stellar centre and a bright core surrounded by a fainter, larger ring. I went back inside to get my girlfriend and have her take a look, and she had the same "wow..." reaction, suggesting that it looked like "a cell" or "a jellyfish". She went back inside then, leaving me alone in the yard with my telescope and the most ridiculous comet I've ever seen. Thought I'd push my luck and try a few photos, just holding my digi camera up to the eyepiece, and this is what I got... Not going to make the Gallery on Spaceweather.com but I'm pretty chuffed with it -------------------- |
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Oct 28 2007, 10:24 PM
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#53
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Wow!!! You got that just from a cam-to-eyepiece shot??? Unreal!
Okay, that's it: gonna see this thing, this event. If I can't see it from home, will do the drive...too damn marvelous to miss! -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Oct 28 2007, 10:35 PM
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#54
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
That was the best out of 80 or so shots; the rest ranged from "it's just there" to "where the **** did it go?!?!"
Had to really push the camera to the limit to get that pic, cos it's a v simple low tech one. Settings: 400ASA, "cloudy", "centre spot metering", and lined up the camera lens with the eyepiece by pushing the lens into half a 35mm film cannister and then placing it against the eyepiece... The view thru the eyepiece was SO much more impressive... I'll have to try simulating it with Photoshop or something. -------------------- |
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Oct 28 2007, 11:42 PM
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#55
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Member Group: Members Posts: 213 Joined: 21-January 07 From: Wigan, England Member No.: 1638 |
Well, if 17P/Holmes is that Saturn-like object near the Moon then I guess I've just observed my first comet. Mind you, I almost broke my neck slipping on the wet grass as I rushed into the house to get my binos...
-------------------- "I got a call from NASA Headquarters wanting a color picture of Venus. I said, “What color would you like it?” - Laurance R. Doyle, former JPL image processing guy
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Oct 29 2007, 01:55 PM
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#56
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Member Group: Members Posts: 345 Joined: 2-May 05 Member No.: 372 |
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Oct 29 2007, 02:28 PM
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#57
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Member Group: Members Posts: 198 Joined: 2-March 05 From: Richmond, VA USA Member No.: 181 |
It's Monday, so what better time than now for a somewhat off the wall question?
With all the (deserved) excitement over comet Holmes, I wondered (as we did here over McNaught earlier this year) if the rovers would be able to see it. My thinking is that it would likely not be as it is well above the ecliptic and the rovers are south of Mars' equator. However, I don't have my copy of Starry Night handy at all to do any tests. Can anyone help on this front? Second (and just as important), is Spirit (or either rover really) in any possition to do even very limited evening or night obs? Again, my guess would be no but I wanted to ask to be sure. Cheers, -- Pertinax |
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Oct 29 2007, 02:48 PM
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#58
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
Great pic um3k! Makes mine look a bit pathetic, but I'm just happy I saw it given the weather here!
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Oct 29 2007, 02:54 PM
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#59
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
I had a quick
Would love some professional input on this... -------------------- |
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Oct 29 2007, 03:38 PM
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#60
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
Spirit's view...
and Oppy's view... Both pics show the comet's highest point in the sky. Again, no idea of brightness, sorry. -------------------- |
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