Talk:C/2014 Q2 (Lovejoy)

Epoch 1950 / 2050
why does that matter? The uncertainty is much too large to make any difference between the two, isn´t it? --Maxus96 (talk) 17:11, 5 January 2015 (UTC)


 * The uncertainty is only around ~1000 years or so. And with a multi-thousand year orbit, the incoming (original) period will generally be different than the outbound (future) period. I would say a change in period of 11,000 to 8,000 years is notable. -- Kheider (talk) 17:59, 5 January 2015 (UTC)

Green Hue?
I have been looking all over the internet for any explanation as to why it appears to have a green hue? Is there any explanations? The only logical connection I can make myself is that the geen hue looks the same as the green observed in Northern Lights which in turn is known to be from Oxygen molecules being enegerqzed by solar particles -- if this is the case are we looking at a comet made up of frozen oxygen? Sorenriise (talk) 01:06, 10 January 2015 (UTC)


 * The comet is green due to the presence of diatomic carbon (C2) -- Kheider (talk) 01:54, 10 January 2015 (UTC)

Original orbit
At epoch 1950, this comet had aphelion ~995AU from the Sun. The MPC lists it with "recip semimajor axis orig (AU)" being positive and 1/a(orig) = 0.002 AU**-1 which is less than 0.000050 AU**-1 so NOT dynamically new. What reference is claiming it came directly from the Oort Cloud? Though it probably came from the Oort Cloud a few orbits ago, suggesting it came DIRECTLY from the Oort Cloud is misleading IMHO. -- Kheider (talk) 20:24, 24 October 2015 (UTC)
 * Okay, but the cited source says "originating from the Oort cloud". Isambard Kingdom (talk) 20:33, 24 October 2015 (UTC)
 * I can not access the source to see the context of the statement. The source may be written by people that do not study orbits or they may simply be suggesting that it "originated from the Oort cloud" on a different pass a long-long time ago. -- Kheider (talk) 20:42, 24 October 2015 (UTC)
 * Isambard Kingdom (talk) 20:44, 24 October 2015 (UTC)
 * First sentence at: http://advances.sciencemag.org/content/1/9/e1500863.full
 * "Comet C/2014 Q2 (Lovejoy) is a long-period comet originating from the Oort cloud, which passed its perihelion on 30 January 2015, at 1.290 astronomical units (AU) from the Sun." Cheers, BatteryIncluded (talk) 20:53, 24 October 2015 (UTC)


 * 1/a(orig) = 0.002 AU**-1 which is less than 0.000050 AU**-1 so NOT dynamically new. Dynamically new comets come from an aphelion (Q) of 20000+AU and thus a semi-major axis (a) > 10000AU. C/2013 A1 (Siding Spring) was a real incoming Oort Cloud comet with a recip semimajor axis orig (AU) of 0.000045. Even more recent papers suggest dynamically new comets come from ~10000+AU. -- Kheider (talk) 21:47, 24 October 2015 (UTC)
 * Aphelion (Qorig) for what many people will think when you emphasize "originating from the Oort cloud": http://www.aanda.org/articles/aa/full/2006/15/aa4284-05/table7.html -- Kheider (talk) 04:24, 25 October 2015 (UTC)
 * Such comments should not be in the lead. Halley's comet has no such statement in the lead. It is the 2nd sentence of the 3rd paragraph of the "Orbit and origin" section: "If Halley was once a long-period comet, it is likely to have originated in the Oort Cloud." -- Kheider (talk) 05:08, 25 October 2015 (UTC)


 * Yes, that change works quite well, thanks. — Huntster (t @ c) 07:22, 25 October 2015 (UTC)

Image from this article to appear as POTD soon
Hello! This is a note to let the editors of this article know that File:C2014 Q2.jpg will be appearing as picture of the day on 2018-11-06. You can view and edit the POTD blurb at Template:POTD/2018-11-06. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. Thanks &mdash; Amakuru (talk) 15:22, 27 October 2018 (UTC)

POV
We are told that visible and ultra-violet light are harsh. This seems to be POV. — Preceding unsigned comment added by 86.146.192.29 (talk) 15:02, 7 November 2018 (UTC)
 * I'm going to change this to "intense". While "harsh" is not really POV, just descriptive, it's probably not the best term to use here. — Huntster (t @ c) 17:47, 7 November 2018 (UTC)