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Comet Fizzle(part 3)

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#1 SteveThornton1

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Posted 29 May 2020 - 05:14 PM

Comet SWAN, Comet ATLAS and Comet ISON.  Just getting tired friends and family about a new comet

that has a good possibility of being bright and then disintegrates.  They just don't make comets like they used to.  I have fond memories of three others; Hale-Bopp, Holmes and Hyakutake


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#2 BrooksObs

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Posted 29 May 2020 - 08:48 PM

C/SWAN, ATLAS, and ISON were already second class objects at discovery and highly unlikely to give a good display as they neared the Sun. It has only been the overblown predictions, too often by hobbyists who don't actually know the first thing about comet behavior, that unrealistically hyped these objects beyond all possible development.

 

C/Hale-Bopp and Hyakutake both held great obvious potential right from the start, the first because of its great intrinsic brightness far from the Sun. the other for how exceptionally close it would pass by Earth. P/Holmes was known to have undergone major photometric outbursts in the past and most such outbursting periodic comets repeat these events from time to time, so no great surprise there either.

 

Incidentally, don't expect to see another comet  whose display equals that of C/Hyakutake. It's show was unrivaled in the past 1,000 years!

 

BrooksObs


Edited by BrooksObs, 29 May 2020 - 08:50 PM.

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#3 chrysalis

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Posted 30 May 2020 - 03:30 AM

Comet Holmes kept me occupied while separated from my family during a job move from CT to GA.

 

Collection of my posts to CN:

 

Attached File  holmes chronicles 2.doc   473.5KB   4 downloads



#4 Octans

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Posted 30 May 2020 - 04:17 AM

Comet SWAN, Comet ATLAS and Comet ISON.  Just getting tired friends and family about a new comet

that has a good possibility of being bright and then disintegrates.  They just don't make comets like they used to.  I have fond memories of three others; Hale-Bopp, Holmes and Hyakutake

There's a distinction to be made between having some remote possibility of being bright and a good possibility of being bright. Neither C/SWAN nor ATLAS ever had much chance of being particularly impressive, even with fairly optimistic brightness extrapolations, unless you were looking ones extrapolating outbursts forward as though they would continue forever. They both had a good chance of being decent, faint naked eye comets, which C/SWAN did achieve. Of the many comets that have any apparent chance of being very bright and impressive (usually get one every year or so), it is guaranteed to be hyped up by people who look at a (usually very badly fit) line on a plot without any clue as to where that line comes from, or what it means. This means the vast majority of hyped up comets will always be duds. This is probably true now more than ever, with the growing social media presence---it now only takes one person who doesn't know what they're looking at to share a completely ridiculous plot and have it spread like wildfire, while no one shares the boring but realistic projections because, well, they're not very exciting...

 

The upcoming C/NEOWISE has a better chance of being "bright" than either of the above ever did, but where "bright" is most likely only faintly naked eye in twilight at best. (Starting to see the hype building here too, but perhaps more subdued as there's no outburst to extrapolate, just badly interpreted data) For what its worth, every now and then, there will be similar comets that, due to unusual structure and/or composition, are very faint at discovery, but turn out to be much bigger comets than are typical of that brightness and subsequently brighten much more rapidly than normal. C/2006 P1 (McNaught) comes to mind. Most comets (despite guaranteed hype) don't do this though, and picking these out from the rest is next to impossible without very high quality data beyond what's normally available soon after discovery.

I will also point out that at its peak, C/ISON was brighter than both Hale-Bopp and Hyakutake at their respective peaks. You probably missed it because this happened ~4 deg away from the Sun (lasting for only an hour or so), and so was only seen with coronagraphs. This was always going to be the case regardless of it survived perihelion---even it had, it would still not have been anything close to Hale-Bopp or Hyakutake by the time it reached dark skies, nor would it have had an impressively long tail like the latter. Brightness isn't everything.


Edited by Octans, 30 May 2020 - 04:22 AM.


#5 chrysalis

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Posted 30 May 2020 - 01:48 PM

One more word: Kohoutek...



#6 John Lowe

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Posted 30 May 2020 - 03:27 PM

Another fizzle:  Comet Austin of 1990



#7 BrooksObs

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Posted 30 May 2020 - 05:22 PM

Octans posts:

 

I will also point out that at its peak, C/ISON was brighter than both Hale-Bopp and Hyakutake at their respective peaks. You probably missed it because this happened ~4 deg away from the Sun (lasting for only an hour or so), and so was only seen with coronagraphs. This was always going to be the case regardless of it survived perihelion---even it had, it would still not have been anything close to Hale-Bopp or Hyakutake by the time it reached dark skies, nor would it have had an impressively long tail like the latter. Brightness isn't everything.

 

 

Actually not true. Sungrazing comets like the Kreutz objects and also the Great Comet of 1680 (which ISON must in some manner have been related, perhaps having separated from it several revolutions ago) generate enormous post-T dust tails typically ranging in length from 0.6 to well over 1.0 AU. Had ISON's nucleus been similar in dimensions to that of he 1680 comet, the potential tail it might have unfurled could easily exceeded 120 degrees in its apparent length as seen from Earth, given the orbital circumstances that prevailed at the time. Not only would it have had prodigious length, but the tail would have been super bright in its surface brightness, just as was the tail of C/Ikeya-Seki, The Great Comet of 1965. Those who saw the latter's brilliant tail shortly following perihelion passage will never forget it as it far exceeded the brightest portions of the Milky Way, even though the comet's head was faint. It made the appearance of the tails of Hale-Bopp or Hyakutake vanishingly insignificant in comparison!

 

BrooksObs


Edited by BrooksObs, 30 May 2020 - 05:25 PM.


#8 Octans

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Posted 30 May 2020 - 06:11 PM

 

Octans posts:

 

I will also point out that at its peak, C/ISON was brighter than both Hale-Bopp and Hyakutake at their respective peaks. You probably missed it because this happened ~4 deg away from the Sun (lasting for only an hour or so), and so was only seen with coronagraphs. This was always going to be the case regardless of it survived perihelion---even it had, it would still not have been anything close to Hale-Bopp or Hyakutake by the time it reached dark skies, nor would it have had an impressively long tail like the latter. Brightness isn't everything.

 

 

Actually not true. Sungrazing comets like the Kreutz objects and also the Great Comet of 1680 (which ISON must in some manner have been related, perhaps having separated from it several revolutions ago) generate enormous post-T dust tails typically ranging in length from 0.6 to well over 1.0 AU. Had ISON's nucleus been similar in dimensions to that of he 1680 comet, the potential tail it might have unfurled could easily exceeded 120 degrees in its apparent length as seen from Earth, given the orbital circumstances that prevailed at the time. Not only would it have had prodigious length, but the tail would have been super bright in its surface brightness, just as was the tail of C/Ikeya-Seki, The Great Comet of 1965. Those who saw the latter's brilliant tail shortly following perihelion passage will never forget it as it far exceeded the brightest portions of the Milky Way, even though the comet's head was faint. It made the appearance of the tails of Hale-Bopp or Hyakutake vanishingly insignificant in comparison!

 

BrooksObs

 

Yes, I was thinking more along the lines of what was physical given what was known about its size in the weeks leading up to perihelion (around the time the comet *really* started getting hyped in the media), when it could theoretically have survived perihelion depending on what its exact properties were, but could still never have produced the display of a "great" sungrazer which needs much more material. I suppose it could've produced something like C/Lovejoy in 2011 with a very well-timed disintegration, but my understanding is that it was visually quite bland despite the impressive photos.



#9 aa6ww

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Posted 30 May 2020 - 07:23 PM

I've never seen a bad comet or one that fizzled out because it was unimpressive. Even ones I can barely detect with my largest Deep space scope are all exciting to me.

My favorite objects in the night sky are comets. Some are more detailed then others and naked eye comets are fun also. Manually hunting for comets already found but hiding inside constellations are pretty fun to look for. Getting up early to catch a comet 20 minutes before sunrise is also pretty fun.

As an astronomer and deep space enthusiast, any comet I can see or even detect is an exciting find to me.

 

...Ralph




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