nice structure in tail before detachment. http://www.spaceweather.com/comets/holm ... rardi1.jpg Quote: Mutability of ion tail. Major changes of shape take place every day. On the left, comet appearance on November 3, right-hand side show the same on November 5. I use negative images to enhance delicate details. I took these photos through a Miniborg 45 refractor with a Starlight Xpress SXV-H9 monocromatic CCD and a blu filter, from a suburban area near centre of Italy. Paolo Berardi, L'Aquila, Italy Nov. 5, 2007
http://www.spaceweather.com/comets/holm ... Jones1.jpg Quote: Stacked & Composited from almost 4 hours of data to show details from core to tail streamers. Clouds limited imaging time. Canon 20D 100-400L @400mm f5.6 ISO1600 initial processing in Iris. AnnMarie Jones, Aberllefenni, Wales, UK Nov. 5, 2007
PostPosted: Tue Nov 13, 2007 3:57 pm
brought to you by the CELIAS/MTOF Proton Monitor on the SOHO Spacecraft MTOF/PM Data by Carrington Rotation 2062 2007 Oct 08 0255 2007 Nov 04 0959 http://umtof.umd.edu/pm/crn/CRN_2062_B2.GIF From top to bottom, the 4 panels represent the following solar wind proton parameters: 1) the bulk speed in kilometers per second 2) the density (protons per cm3) 3) the most probable thermal speed (km/sec) = Sqrt(2kT/m) 4) the flow direction in the plane perpendicular to the ecliptic plane, with positive values indicating flow FROM the south. On rare occassions the spacecraft's roll angle is changed for brief periods, during which the derived flow direction will refer to a different plane. A list of such times is available. http://umtof.umd.edu/pm/
StefanR
Re: Recovered: Holmes gets very bright
SeaSmith Posted: Wed Nov 14, 2007 1:01 am Post subject: Reply with quote FS3 wrote: -------------------------------------------------------------------------------- Quote: earls wrote: "Additionally I do think geometry plays a crucical role - as the planets can be seen as nodes in a frequency pattern - that our Solar System is "humming"..."
...Yikes. Brilliant. Now... How do you hear the music?
Quote: "Sound waves are pressure waves. And black holes, or at least their relativistic jets, can generate enormous sound waves, which then propagate through surrounding galactic gas," explains astronomer Steven Allen, a professor of physics at Stanford University who studies the Perseus galaxy cluster. "When relativistic jets, which contain material moving at close to the speed of light, slam into the hot gas that pervades giant elliptical galaxies and clusters of galaxies, they beat a 'galactic drum,' as it were." The jet acts as the "stick," whereas the surface of the gas is the "drum."
Posted: Wed Nov 14, 2007 8:27 am Post subject: Reply with quote Ion01 wrote: The comet must be fading significantly in brightness. I have been watching closely with my very amatuer reflector telescope. It is becoming a strain to see not only with the naked eye but even in my telescope. I new it wouldn't last forever but its really disappointing. Sad
Maybe it will flare up again like in 1892. I have been looking for parallels in the circumstances, but there seem to be none. Today we have almost no sunspots, in 1892 there were many.
from Sunspots in history:
StefanR
Re: Recovered: Holmes gets very bright
StefanR Posted: Wed Nov 14, 2007 9:27 am Post subject: brightness holmes Reply with quote Ion01 wrote: The comet must be fading significantly in brightness. I have been watching closely with my very amatuer reflector telescope. It is becoming a strain to see not only with the naked eye but even in my telescope. I new it wouldn't last forever but its really disappointing. Sad
Posted: Wed Nov 14, 2007 3:05 pm Post subject: Reply with quote Quote: Maybe it will flare up again like in 1892. I have been looking for parallels in the circumstances, but there seem to be none. Today we have almost no sunspots, in 1892 there were many.
Maybe the coronal hole which has returned will have some influence? Round the 24th there was one and there was the accompanying higher speed and temp of the 'wind'. Then the next change was by an 'small' CME around the 7th and 8th after which the tail disconnected on about the 9th. And now we see the next (or is it the same?) coronal hole and the speed of the 'wind' picking up again, so maybe tomorrow or the day after there might be change. If the events are corrolated that is. Confused
StefanR
Re: Recovered: Holmes gets very bright
Biknewb Posted: Wed Nov 14, 2007 3:21 pm Post subject: Reply with quote Even if the coronal hole has influence, it cannot be the cause of the flare up. Holmes has been dark for more than a century. There have certainly been more and bigger CME's in that period and none of them made Holmes even blink. Something activated this comet. But what was it?
StefanR
Re: Recovered: Holmes gets very bright
Nick C Posted: Wed Nov 14, 2007 4:29 pm Post subject: homes 17P Reply with quote Ion01 wrote: The comet must be fading significantly in brightness. I have been watching closely with my very amatuer reflector telescope. It is becoming a strain to see not only with the naked eye but even in my telescope. I new it wouldn't last forever but its really disappointing. Sad
I have been observing the comet with a 6" reflector and have not noticed any dimming in overall brightness although, I believe that the Earth is now moving away from the Comet. I last looked last night (Nov. 13.) What I have seen is that it's diameter is increasing so that it is now larger than a full moon in the eyepiece's field of view, so the brightness may be spread out over a larger area. It has been passing in front of an area of the Milky Way in Perseus that is densely packed with stars, many of which can be seen shining thru the coma. It is visible to the naked eye as a fuzzy star, not as intense as a week ago, but much larger. What is interesting is the absence of explanations by astronomers, their silence is deafening! I get the impression that this is a very painful anomaly. You would think that people who are capable of "knowing" what happened in each milisecond after the universe was created or capable of calculating how much matter is "missing" from the universe could explain the actions of a simple little comet! Also, I have not found any mention of light being emitted by the comet (ie- it's plasmasphere in glow mode or if that is even a possibility) according to every source I have read, the comet is a tenuous ball of small particles forming a roughly spherical shape larger than Jupiter and is shining by reflecting sunlight. It must be tenuous indeed, since background stars can be seen even through the inner coma! It will no doubt start to fizzle out soon. In the 1890's there was a 2nd flare up a few months later, of course there is no guarantee of those events being repeated. It will be interesting.
StefanR
Re: Recovered: Holmes gets very bright
Ion01 Posted: Wed Nov 14, 2007 5:21 pm Post subject: Reply with quote I thought that maybe the loss in "brightness" may be due to its size getting larger. I also have a 6 inch reflector and it almost fills the entire view now. (I am not sure of the magnification of the lense.) Still, this has been one of the most exiting things I have seen in the sky!
StefanR
Re: Recovered: Holmes gets very bright
StefanR Posted: Wed Nov 14, 2007 6:15 pm Post subject: re: homes 17P Reply with quote Quote: Also, I have not found any mention of light being emitted by the comet
Check out the link from page 5 of this thread at Sat Nov 03, 2007 12:30 am :
When Asteroids Become Comets A comet is simply an electrical display and was recognized as such by scientists in the 19th century. So an 'asteroid' on a sufficiently elliptical orbit will do precisely what a comet does—it will discharge electrically. What distinguishes the cometary 'asteroids', observed by the University of Hawaii astronomers, are the paths they follow, moving them through the radial electric field of the Sun to a greater extent than is typical of other bodies in the 'asteroid belt' (See chart above). Cometary effects may also be expected from an asteroid if it passes through the huge electric comet tail [called the magnetosphere] of a giant planet. http://www.thunderbolts.info/tpod/2006/ ... teroid.htm
or
Clandestine comets found in main asteroid belt Jewitt says based on their nearly circular, stable orbits, the main belt comets are "completely asteroidal". You would never guess that they were anything but asteroids." But in terms of appearance, with their long-lasting tails, he says "they're definitely comets". The team believes in order to survive at such proximity to the Sun, the volatiles in the main belt comets would have to be covered by a layer of possibly carbonaceous material. They say an impact event could then uncover some of the volatiles, allowing the Sun's heat to trigger the observed outgassing. Activated asteroids Asteroid expert Richard Binzel at MIT questions the need for the new classification. "I prefer to think of them as activated asteroids," he told New Scientist. "It's no surprise if some asteroids have some water content, particularly in the outer asteroid belt." He says volatiles have been measured to make up about 10% of some carbonaceous meteorites that are thought to come from the region. Jewitt says potentially tens of thousands of main belt objects contain ice and have simply not been observed during their active period. In order to be seen spewing dust, the objects would have to have been hit by a meteor size boulder within the last thousand years or so, he adds. http://space.newscientist.com/article/dn8887
So wouldn't that mean that for the electric view there is no actual need for a cause, as the comet is the cause itself? And how is it possible to verify either of the two causes? Confused
Quote: "Most of what Hubble sees is sunlight scattered from microscopic particles," explained Hal Weaver of The Johns Hopkins University Applied Physics Laboratory of Laurel, Maryland in the USA, who led the Hubble investigation.
Dumb Question: My understanding was that Comet Holmes is somewhat close to being in the shadow of one of several planets relative to the Sun. People on this board have been looking at the trajectory in close depth. The object is as large as the Sun now, which should increase the chances that we should be seeing planetary shadows on the supposedly sunlit particles, right? ...
e-man Posted: Sat Nov 17, 2007 1:15 am Post subject: Reply with quote Harold Weaver — the same as cited by pln2bz in the sciencedaily link above — requested Hubble shots ("Investigating the Spectacular Outburst of Comet 17P/Holmes, HST Proposal 11418, Harold Weaver, The Johns Hopkins University Applied Physics Laboratory"). The Hubble shots were taken.
DustyDevil Posted: Sat Nov 17, 2007 5:07 pm Post subject: Reply with quote Hubble images of Holmes have been released. Here's the link to the press release:
Personally, I'm not impressed with these Hubble images; Hubble may not be a suitable instrument for studying Holmes. I'd love to see Holmes imaged in X-ray and UV wavelengths. Here's the link to the image download page:
Thanks, DustyDevil. I agree and disagree with you. The highest res images (e.g. the print.jpg off of http://hubblesite.org/newscenter/archiv ... 0/image/a/) are so narrow range that they seem to be more featureless than the wider-angle ground based shots. But they actually reveal some noteworthy things.
Credit for Hubble Image: NASA, ESA, and H. Weaver (The Johns Hopkins University Applied Physics Laboratory) Credit for Ground-based Image: A. Dyer, Alberta, Canada
Not the least of which is that there are no observed fragments, which to some degree discounts the hypothesis that Holmes "exploded" due to an impact. That's even noted on the press release: newscenter wrote:
The Hubble images, however, do not show any large fragments near the nucleus of Comet Holmes, unlike the case of Comet 73P/Schwassmann-Wachmann 3 (SW3). In the spring of 2006 Hubble observations revealed a multitude of "mini-comets" ejected by SW3 after the comet increased dramatically in brightness.
Ground-based images of Comet Holmes show a large, spherically symmetrical cloud of dust that is offset from the nucleus, suggesting that a large fragment broke off and subsequently disintegrated into tiny dust particles after moving away from the main nucleus.
Unfortunately, the huge amount of dust near the comet's nucleus and the comet's relatively large distance from Earth (149 million miles, or 1.6 astronomical units, for Holmes versus 9 million, or 0.1 astronomical unit for SW3), make detecting fragments near Holmes nearly impossible right now, unless the fragments are nearly as large as the nucleus itself.
But, to me, even more telling is this: newscenter wrote:
The central portion of the image has been specially processed to highlight variations in the dust distribution near the nucleus. About twice as much dust lies along the east-west direction (the horizontal direction) as along the north-south direction (the vertical direction), giving the comet a "bow tie" appearance. [emphasis mine]
I'd dearly love to see some mechanical dynamics expert come up with the math for how a bow tie, of such vast size and clean boundaries, could arise from an impact.
Bow-ties are trivially obtained through electric field focusing effects. But, oh my, that would require acknowledgment that there are overt electrical effects in the sacrosanct electrically neutral universe. Intergalactic gas couldn't possibly be affected that way. It's all Brownian motion and thermal effects, and oh, yes, gravity (is that oddly behaving comet made of that dark matter stuff?).
StefanR
Re: Recovered: Holmes gets very bright
MGmirkin Posted: Sun Nov 18, 2007 9:11 pm Post subject: Merging thread... Reply with quote A little maintenance...
Just trying to keep from forking the conversation...
Cheers, ~Michael Gmirkin
In another thread, George DeCarlo wrote: ** I had read this article below posted on the web and took a chance to enter 1892 with climate and temperature and found that that year had some unusual activity. Any comments? Could this comet simply be a sign of increased electrical activity also causing our small planet some heating from the outside? — George
Incredible Comet Bigger than the Sun Robert Roy Britt Senior Science Writer SPACE.com Thu Nov 15, 10:45 AM ET
A comet that has delighted backyard astronomers in recent weeks after an unexpected eruption has now grown larger than the sun.
The sun remains by far the most massive object in the solar system, with an extended influence of particles that reaches all the planets. But the comparatively tiny Comet Holmes has released so much gas and dust that its extended atmosphere, or coma, is larger than the diameter of the sun. The comparison is clear in a new image.
"It continues to expand and is now the largest single object in the solar system," according to astronomers at the University of Hawaii.
The coma's diameter on Nov. 9 was 869,900 miles (1.4 million kilometers), based on measurements by Rachel Stevenson, Jan Kleyna and Pedro Lacerda of the University of Hawaii Institute for Astronomy. They used observations from the Canada-France-Hawaii Telescope. The sun's diameter, stated differently by various sources and usually rounded to the nearest 100, is about 864,900 miles (1.392 million kilometers).
Separately, a new Hubble Space Telescope photo of the comet reveals an intriguing bow-tie structure around its nucleus.
The comet's coma—mostly microscopic particles—shines by reflecting sunlight.
See for yourself
Holmes is still visible to the naked eye as a fuzzy star anytime after dark, high in the northeast sky. You can find it by using this sky map. It is faintly visible from cities, and from dark country locations is truly remarkable.
"Right now, in a dark sky it appears as a very noticeable circular cloud," said Joe Rao, SPACE.com's Skywatching Columnist. Rao advises looking for the comet this weekend, before the moon becomes more of a factor. The comet will likely diminish in brightness yet remain visible for the next two to three weeks, he said.
"Over the next few weeks and months, the coma and tail are expected to expand even more while the comet will fade as the dust disperses," Stevenson and her colleagues write.
On Monday, Nov. 19, the comet will create a unique skywatching event with its see-through coma, according to the Web site Spaceweather.com: "The comet will glide by the star Mirfak [also called Alpha Persei] and appear to swallow it—a sight not to be missed."
A small telescope will reveal the fuzzy coma. Lacking a long tail characteristic of some great comets, however, Holmes is not the most dramatic object in the sky for casual observers.
Mystery outburst
Nobody knows why Holmes erupted, but it underwent a similar explosive brightening in 1892. The recent display, which began Oct. 24, brought the comet from visual obscurity to being one of the brighter objects in the night sky. It has since dimmed somewhat as the material races outward from the nucleus at roughly 1,100 mph (0.5 km/sec).
The Hawaiian astronomy team writes in a press statement: "This amazing eruption of the comet is produced by dust ejected from a tiny solid nucleus made of ice and rock, only 3.6 kilometers (roughly 2.2 miles) in diameter."
The new image from the Hawaiian observatory also shows a modest tail forming to one side, now just a fuzzy region to the lower-right. That's caused by the pressure of sunlight pushing on the gas and dust of the coma.
But the comet is so far away—149 million miles (240 million kilometers), or about 1.6 times the distance from Earth to the sun—that even Hubble can't resolve its nucleus.
The offset nature of the coma, seen in ground-based images, suggests "a large fragment broke off and subsequently disintegrated into tiny dust particles after moving away from the main nucleus," Hubble astronomers said in a statement today. The comet's distance, plus all the dust, prevent Hubble from seeing any fragments, however.
Posted: Sun Nov 18, 2007 9:23 pm Post subject: Comet Holmes vs. the Boomerag Nebula? Reply with quote e-Man wrote: Credit for Hubble Image: NASA, ESA, and H. Weaver (The Johns Hopkins University Applied Physics Laboratory) Credit for Ground-based Image: A. Dyer, Alberta, Canada
Now, I'll be the first to admit that this may or may not be related (how's that for equivocating?)...
But, for some reason this image (the upper-right inset image, specifically) STRONGLY reminds me of the following image:
Might simply be similar but no relation... But, nonetheless, it intrigues me a bit. I'm wondering if one can shed light on the other, and/or vice versa?
StefanR
Re: Recovered: Holmes gets very bright
davesmith_au Posted: Sun Nov 18, 2007 10:38 pm Post subject: Re: Comet Holmes vs. the Boomerag Nebula? ... Reply with quote I had exactly these thoughts when I first saw that article too Michael.
There's umpteen examples of this 'shape' within the cosmos, and scalability being what it is, I thought Red Square nebula, hourglass nebula, boomerang nebula, etc, etc, etc. I think it's quite fair to at least make the comparison, without necessarily drawing definite conclusions therefrom.
Biknewb Posted: Mon Nov 19, 2007 7:38 am Post subject: Comet Holmes vs. the Boomerang Nebula? Reply with quote Supposing this hourglass shape is a current filament, focusing on the comet, then this picture shows it sideways. That means imho that the current is going left to right or right to left, seen from Hubble. Where in this picture would the Sun be? (Always had low grades for space geography in kindergarten. Sad )
Stefanr Posted: Tue Nov 20, 2007 2:46 pm Post subject: loading comets Reply with quote Could it be possible for a comet/asteroid to build up a load during several revolutions around the sun, during which it gives normal periodic brightening but after some revolutions having to discharge more violently?
Biknewb Posted: Tue Nov 20, 2007 3:09 pm Post subject: Re: loading comets Reply with quote This is not the standard explanation of electric comet theory. (Going against anti-mainstream are we? LOL) The idea in itself is not bad, but I can see no charging mechanism yet. And what about all the other comet/asteroids out there? Shouldn't they also discharge now and then?
Stefanr Posted: Tue Nov 20, 2007 3:33 pm But still this also happens:
Quote: Of course, this is not the first instance of an 'asteroid' sporting a cometary tail. The asteroid Chiron, orbiting between Saturn and Uranus, was seen to develop a coma and tail between 1988 and 1989. It is now officially classified as both an asteroid and a comet. Chiron belongs to a class of objects called 'Centaurs' crossing the orbits of various gas giants. Though they move on minimally eccentric orbits through a relatively remote and weak region of the Sun's electric field, Wallace Thornhill and other electrical theorists believe these bodies should all be watched carefully for telltale signs of minor cometary activity. And in fact the asteroid 60558 Echeclus, discovered in 2000, did display a cometary coma detected in 2005, and it too is now classified as both an asteroid and a comet.http://www.thunderbolts.info/tpod/2006/ ... teroid.htm
What is the threshold point of discharching of any asteroidal/cometary object? How does the nature of discharging (electrically we now there are several 'modes') relate to the eccentricity of the orbit of such objects?
Quote: A comet nucleus can be compared to the insulating material in a capacitor. As charge is exchanged from the comet's surface to the solar wind, electrical energy is stored in the nucleus in the form of charge polarization. This can easily build up intense mechanical stress in the comet nucleus, which may be released catastrophically, as in a capacitor when its insulation suffers rapid breakdown. The comet will explode!http://www.thunderbolts.info/tpod/2005/arch05/050520linear.htm
StefanR
Re: Recovered: Holmes gets very bright
**** PAGE 12 SEEMS LOST ****
StefanR
Re: Recovered: Holmes gets very bright
StefanR Posted: Thu Nov 22, 2007 11:16 pm Post subject: re: Odd thought and novice question for the experts Reply with quote e-man wrote: Now, what would happen if the rotation of the skirt happened to form a near correspondence with the orbit of the asteroid Holmes? If the EU theory for comets is such that they slowly balance charge with their surrounds, and the exchange rate is generally so slow that they retain a significant charge upon close approach to the sun, resulting in the coronal discharge and other DL discharge events, then... [taking a deep breath before finishing this rambling sentence]...
If Holmes, over time rubbed against one particular polarity of the sheet until it balanced, but at some point — like every 100 years, the phase differential allowed it to pass through the inverse majority charge region of the ballerina skirt, then wouldn't that suffice to provide the analogous electrical environment to the longer period comets?
StefanR wrote: What is the threshold point of discharching of any asteroidal/cometary object? How does the nature of discharging (electrically we now there are several 'modes') relate to the eccentricity of the orbit of such objects?
Quote: A comet nucleus can be compared to the insulating material in a capacitor. As charge is exchanged from the comet's surface to the solar wind, electrical energy is stored in the nucleus in the form of charge polarization. This can easily build up intense mechanical stress in the comet nucleus, which may be released catastrophically, as in a capacitor when its insulation suffers rapid breakdown. The comet will explode!http://www.thunderbolts.info/tpod/2005/arch05/050520linear.htm
That's great e-man, I was thinking in the same direction. Maybe even the current sheath itself might be not that important. As stated in the quote above a comet nucleaus can be compared to the insulating material in a capacitor. Could there be some mechanism whereby the accumulating dust on the nucleus before a discharge (like one also can see on asteroids) plays a role in the timing of the discharge. Like a slowly growing insulating layer, which grows during charging the load? Like some sort of materialisation of the double layer between comet nucleus and environment?
Biknewb Posted: Fri Nov 23, 2007 8:14 am Post subject: Odd thoughts Reply with quote E-man and StefanR, these are the kind of mechanisms that would account for the long period between the flare-ups of Holmes. Smile
The possibillity of a phase-lock with the Sun's rotating current sheet can be calculated. Don't know if there is enough data available. I also like the idea of a slow build-up of dust that gets blown off periodically when some threshold insulation value is reached.
What is so special about this inconspicuous little boulder on its seemingly average orbit? Question
E-man Posted: Fri Nov 23, 2007 10:23 pm Post subject: Re: Odd thoughts Reply with quote
biknewb, I'd opine that it's not at all a given that such a phase-lock can be calculated. Instabilities in currents and discharges would seem to beg that long-term calculations cannot be adequately performed. If (huge if) we could ascertain what the current sheet's configuration was from empirical measurements at various points, interpolation might help approximate the actual relationship between the sheet and Holmes. But I'm just not aware of any data more precise than spot determinations that confirmed the general shape and behavior of the rotating sheet. Crying or Very sad So much potential data, so little knowledge about it.
But, on the brighter side, there is an increasing body of empirical data forming courtesy of all the various space weather observational satellites.
biknewb wrote:
What is so special about this inconspicuous little boulder on its seemingly average orbit? Question
Someone somewhere else in the forum suggested that the one and only way to resolve the question would be to put a multi-measuring satellite into the same orbit as the asteroid/comet, leading it (presumably so as to remain minimally affected by the ionic trailings of the comet phase).
Hard data that's hard to get.
But, agreeing with so many other comments, the true electrical nature of the universe is likely to be most unquestionably exposed by studying comets. And, Holmes, with such astonishing behavior, seems like the prime candidate to study. Plus, it offers so many benefits over other comets, not the least of which being its relative proximity to the earth and its short orbital period.
