As an aside, why is it so difficult to estimate a comet’s brightness? What variables are fuzzy?
Chronos
August 22, 2013, 10:58pm
22
The comet itself is, literally. We can pin down the orbit pretty precisely, once we’ve observed it for a month or two, but it’s harder to determine the mass, and even if you know that, it’s almost impossible to know how much it will outgas. The gas cloud of a comet (or coma) can be bigger than the Earth… Or it can be almost nonexistent.
Hot Fudge Sundae* (Lucifers Hammer reference)
MonkeyMensch:
My guess is that ISON will break up before aphelion, shortly after passing the Roche limit, and then get its butt roasted, sice the surface to mass ratio will greatly increase after break up. But, given that aphelion passage (around Thanksgiving for the Yanks) will be just marginally visible due to its proximity to the Sun maybe there’ll be something to see.
Don’t you mean perihelion?
I certainly do; nice catch. It’s funny as you proofread a post for spelling and grammar little things like word meaning can slip through the sieve.
Johanna
August 23, 2013, 10:28pm
26
'S OK. Aphelion your pain.
Spelling checkers have a long ways to go, eh? What self-respecting spelling checker of 2020 would miss that glaring error?
And spelling checkers don’t detect bad puns. Yet, so watch out.
Knorf
November 29, 2013, 5:34am
28
Sadly, it looks like comet C/2012 S1 (known as Comet ISON) has broken up at or close to perihelion . Bummer.
Gyrate
November 29, 2013, 12:46pm
30
Knorf
November 29, 2013, 11:44pm
31
Indeed! It knows appears that the comet is not quite dead , yet.
Tentative “woo-hoo.”
DrDeth
November 30, 2013, 12:41am
32
Spectre_of_Pithecanthropus:
I saw Hale-Bopp from a beach west of Malibu; which is still considerably light polluted if not nearly as bad as most of L.A. County. It was a bit diffuse and faint, perhaps about as prominent as a first magnitude star allowing for the comet’s more diffuse structure. But there was no mistaking it, and it was spectacular enough that I was able to see it without deliberately looking for it.
Spectacular? To me it looked like a fuzzy star. We havent had many really spectacular comets in living memory:
The Great January Comet of 1910, formally designated C/1910 A1 and often referred to as the Daylight Comet, was a comet which appeared in January 1910. It was already visible to the naked eye when it was first noticed, and many people independently "discovered" the comet. At its brightest, it outshone the planet Venus, and was possibly the brightest comet of the 20th century.
The comet came to solar conjunction about 1 degree from the Sun on 17 December 1909 but was still about 1 AU from the Sun...
The Great Comet of 1843, formally designated C/1843 D1 and 1843 I, was a long-period comet which became very bright in March 1843 (it is also known as the Great March Comet). It was discovered on February 5, 1843, and rapidly brightened to become a great comet. It was a member of the Kreutz Sungrazers, a family of comets resulting from the breakup of a parent comet (X/1106 C1) into multiple fragments in about 1106. These comets pass extremely close to the surface of the Sun—within a few solar rad...
The Great Comet of 1744, whose official designation is C/1743 X1, and which is also known as Comet de Chéseaux or Comet Klinkenberg-Chéseaux, was a spectacular comet that was observed during 1743 and 1744. It was discovered independently in late November 1743 by Jan de Munck, in the second week of December by Dirk Klinkenberg, and, four days later, by Jean-Philippe de Chéseaux. It became visible with the naked eye for several months in 1744 and displayed dramatic and unusual effects in the sky. I...
The Great Comet of 1882, formally designated as C/1882 R1, 1882 II, and 1882b, was a comet which became very bright in September 1882. It was a member of the Kreutz Sungrazers, a family of comets which pass within 1 R☉ of the Sun's photosphere at perihelion.
The comet was bright enough to be visible next to the Sun in the daytime sky at its perihelion. The comet made its closest approach to Earth on 16 September 1882 at 0.99 AU and then came to perihelion (closest approach to the Sun) the next d...
But the one I personally remember was Comet Ikeya–Seki - Wikipedia
Visible in the daytime, but rather close to the sun.
ftg
November 30, 2013, 9:00pm
33
Comet West in 1976 was quite beautiful. I saw it in the early morning light with a very long classic comet tail. All the other comets I’ve seen were just fuzzballs by comparison. The press coverage was basically nil due to the overhype of Kohoutek the previous year.
West, like quite a few other comets, was also visible in the daytime. This really isn’t that rare. You just need to know where to look. Phil Plait , for example, saw McNaught with binoculars at noon. Hardly a great comet.
I would like to salute Karl Battams, astrophysicist at the Naval Research Laboratory, for clarifying the state of the comet in the New York Times.
“It’s definitely maybe alive,” Battams said. “There’s a strong definite chance it might be, may be alive.”
Thanks, Karl! There’s a big future for you working in the White House press office.
First there is a comet
Knorf
December 3, 2013, 3:40pm
36
Nope. Looks like its nearly dead after all .
Quite the drama, though.
As one of the commenters on the CBC site said:
Comet ISON.
So it wasn’t visible in daylight; but it was still sufficiently bright and well defined that I could easily make out the object and its classic “comet” shape. I say it was real, and it was spectacular!
Bullitt
December 11, 2013, 6:13am
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