kheider notes[edit]

Qiсһеng Ζһаng: brightening at n~8 since entering C3, which is far above what's typical of a stable comet. -- Kheider (talk) 20:19, 25 June 2020 (UTC)[reply]

Trajectory section[edit]

This is actually as it is seen from Earth, right? Bubba73 You talkin' to me? 20:33, 11 July 2020 (UTC)[reply]

Yes, the retrograde loops are parallax from earth's annual motion around the sun. Tom Ruen (talk) 20:45, 11 July 2020 (UTC)[reply]
That is what I thought - could be confusing to someone seeing it. The new caption works. Bubba73 You talkin' to me? 03:58, 12 July 2020 (UTC)[reply]

What is the continuous yellow arc in Comet_2020_F3-skyview.png ("Comet position in the sky.")? BMJ-pdx (talk) 12:32, 14 July 2020 (UTC)[reply]

This is the ecliptic or the apparent annual path of the Sun. AstroLynx (talk) 14:00, 14 July 2020 (UTC)[reply]

Gallery section[edit]

I don't think the gallery section should have been removed, for the same reason as why we maintain galleries for eclipses/etc. The section provided a good insight on how it is/was visible. I'd suggest leaving at least the best dozen (one per country). Cheers, Rehman 12:13, 12 July 2020 (UTC)[reply]

Of course the page should have a gallery section. Maybe one problem was the duplication of too many similar images, and the gallery should show the progression of comet views. Randy Kryn (talk) 12:27, 12 July 2020 (UTC)[reply]
There were 12 wide angle photos that all basically showed the same thing. It was overkill. Four photos could have done the same thing, but then editors will probably fight over which four backgrounds they like. -- Kheider (talk) 12:49, 12 July 2020 (UTC)[reply]
Maybe leave two or three for now, and then pagewatchers can choose from additions as the comet is seen and photographed more. A gallery in some form is almost essential for a popularly promoted comet such as Neowise. Maybe a hidden note to ask editors not to duplicate already familiar and included images would hold down the parade of photos. Randy Kryn (talk) 13:00, 12 July 2020 (UTC)[reply]
Agree with Randy. Alternatively, maybe we could simple leave it open (as is the case with most other articles such as eclipses), and remove those that are of bad quality or seemingly duplicates of better images. Having the section (even with a couple of duplicates slipping through) certainly does more good than bad. Rehman 13:50, 12 July 2020 (UTC)[reply]
The page is up to 42,000 daily views now, so should probably put back a limited gallery to show readers what it might look like from an on-the-ground perspective. Randy Kryn (talk) 20:24, 12 July 2020 (UTC)[reply]
I went ahead and restored the gallery that was initially there. The selection may need to be updated, as there now seems to be some new good ones on Commons. Cheers, Rehman 05:14, 13 July 2020 (UTC)[reply]
Thanks. Did some trimming of the images, should get some good ones daily so determination of what to keep should be maintained so the gallery doesn't get too large, but 12 to 18 images could be shown without losing interest. Up to 48,000 daily views, so presenting an educational encyclopedic page while not going overboard on images, but still having a nice selection, will give those seeking information a nice overview. Randy Kryn (talk) 13:03, 13 July 2020 (UTC)[reply]
Here's a rather nice shot of the comet over Stonehenge for consideration. Don't know what the copyright status is, though. And I'd really like to see the shot from Parker Solar Probe included. Surely that beats any Earthbound viewpoint, no matter how picturesque? 88.145.188.153 (talk) 22:51, 13 July 2020 (UTC)[reply]

Sodium[edit]

Single-purpose account Galaxactic seems to be promoting himself with twitter. -- Kheider (talk) 07:57, 15 July 2020 (UTC)[reply]

The issue seems to be the discovery of sodium in the comet. People were tweeting about this on the 12th but Chris Schur had found sodium in the spectrum on July 11. I'd have thought that spectroscopic analysis would have been done weeks ago but my quick browse only finds recent stuff like this. Andrew🐉(talk) 10:56, 15 July 2020 (UTC)[reply]

Hi there! I'm Galaxactic. There seems to be a lot of confusion so I thought I'd make it more clear. I am not the one who wrote the paragraph about the twitter users, as you can see it was by an anonymous user with a specific IP Adress. I am not associated with anyone that was mentionned in the paragraph at all, you might have thought I was "GalacticMilk" but it's a pure coincidence that our names are similar, I'm new on Wikipedia. I am also aware that I did a mistake by not searching for a better source earlier but I was asleep. Here is a scientific paper published this morning by the person who actually discovered the sodium tail. So yes, it's the twitter guy who discovered first the sodium tail. Best Regards, Galaxactic(talk) —Preceding undated comment added 11:54, 15 July 2020 (UTC)[reply]

Space.com also has an article "Comet NEOWISE has a sodium tail. Here's what it looks like." -- Kheider (talk) 18:36, 15 July 2020 (UTC)[reply]

Apparent magnitude[edit]

I saw it listed on here that NEOWISE's apparent magnitude was +2.9. This is based off a single data point by Carl Hergenrother. Let's avoid using a single observation by one individual. COBS lists the comet at +2.0. astro.vanbuitenen.nl lists it at 1.6. — Preceding unsigned comment added by Kdenny994 (talk • contribs) 19:18, 15 July 2020 (UTC)[reply]

As of July 15, COBS is using data from July 15 and lists 1.4–2.9 while http://astro.vanbuitenen.nl/cometobs seems to be a single observer from July 11. Four days can be a long time if a comet is fading. -- Kheider (talk) 23:37, 15 July 2020 (UTC)[reply]
The excessive "naked eye" language on the page should be toned down and made clear that this comet is not easily seen by the naked eye in urban areas. This is not a spectacular comet and needs binoculars to view, which should be made clear (wording to that effect was deleted a day or so ago). Randy Kryn (talk) 14:33, 19 July 2020 (UTC)[reply]
The current language of the lead seems fine:

By July 2020, it was bright enough to be visible to the naked eye. It is one of the brightest comets in the northern hemisphere since Comet Hale–Bopp in 1997 and was widely observed as being clearly visible with the naked eye. It has been considered by Seiichi Yoshida and Farmer's Almanac as a possible Great comet, and NASA noted that it could become known as a great comet. However, this distinction is usually reserved for comets that are easily observable with the naked eye, even with low to moderate light pollution. Under dark skies, it can be clearly seen with the naked eye and might remain visible to the naked eye throughout most of July 2020, at least until July 23, the point of the comet's closest approach to Earth. Prior to that date, the comet will be getting closer to Earth as it moves farther away from the Sun. As of July 18, the comet is about magnitude 3.[1] Near urban areas binoculars are required to locate the comet.

Andrew🐉(talk) 20:44, 19 July 2020 (UTC)[reply]

References

  1. ^ Cite error: The named reference COBS was invoked but never defined (see the help page).

"Visible to naked eye" ?[edit]

I think a caveat needs to accompany any mention of the comet being visible to the naked eye.

Here in Phoenix, AZ, the comet is only visible if you have binoculars &/or a telescope. It is not visible to the naked eye.

To see the comet like all the photos show and w/o binocs/'scope, you have to be away from the glow of city lights.

Thoughts/comments ? 2600:8800:784:8F00:C23F:D5FF:FEC4:D51D (talk) 13:37, 20 July 2020 (UTC)[reply]

From a dark site, experienced observers can still detect the comet with the naked eye. Anyone near urban areas will need binoculars. You will never see a comet as well as a tripod-mounted camera taking shots of 30 seconds or more. -- Kheider (talk) 14:14, 20 July 2020 (UTC)[reply]
My wife and I saw it (but not the tail(s)) with our naked eyes, through the high ambient light of the City of Chicago's north side (West Rogers Park), just north of due east, around 4 AM CDT of July 24 and 25, respectively. It was considerably brighter than Venus ever is, and certainly brighter than Mars or Jupiter, all three of which can sometimes be seen from here with my (far-sighted) naked eyes. Acwilson9 (talk) 21:39, 26 July 2020 (UTC)[reply]
It should be a faint fuzzy somewhat like Andromeda Galaxy. If it was brighter than Venus, you were not looking at the comet. Venus is about 40 degrees East of Sun right now. -- Kheider (talk) 21:55, 26 July 2020 (UTC)[reply]
You are right; we were seeing Venus, not the comet. Acwilson9 (talk) 16:20, 27 July 2020 (UTC)[reply]

Gallery section[edit]

This section is little more than a magnet for self-promoting amateur astronomers. Looking at the history, at least ten of the 14 images currently in it were put there by the people who took them (eg [1], [2], [3], [4], [5], [6], [7], [8]). There is no limit to the number of nice images of the comet that could be suitably licensed, and the point of a gallery section is not to simply have a large collection of arbitrarily chosen images - Wikimedia Commons provides that - but to illustrate an aspect of the topic that a single image cannot. The section does not do that.

I suggest that would would be very valuable would be a set of a maximum of five or six images, from dates selected such that the evolution of the comet is clearly depicted. Faint fuzzy blob -> brighter fuzzy blob -> tails -> very bright and visible over city lights -> fading. That would be encyclopaedic. I would also suggest that a hidden comment be added, requesting that people do not add their own photos. Unless the image clearly illustrates some aspect of the topic not already illustrated, it is simply self-promotion to do so, a misuse of the large exposure that a Wikipedia article affords. Sankura (talk) 11:51, 21 July 2020 (UTC)[reply]

Amateur astronomy is a thing. Many comets have been discovered by such, savvy? kencf0618 (talk) 13:54, 23 July 2020 (UTC)[reply]
Um, what? Sankura (talk) 10:26, 24 July 2020 (UTC)[reply]

Suggested trimming

Remove


Keep

Not sure

Resulting gallery

©Geni (talk) 04:31, 24 July 2020 (UTC)[reply]

Personally I would say that two timelapse videos is unnecessary. I don't think even one is necessary really. If you could see it moving against the background stars, that would be cool but I don't see that in these. Honestly, I don't see the need for this gallery section at all right now. I could not see any set that would illustrate the evolution of the comet. I'd retain one wide-field view and one close-up view only, out of the current images. The first two of your keepers would be fine by me, though I also like the one over the Golden Gate Bridge. With two images retained, there would be a total of 7 images in the article. Given that there are only 11 paragraphs of text in total, that seems proportionate. Sankura (talk) 10:26, 24 July 2020 (UTC)[reply]
If we are going to have a gallery I'd suggest sticking with 4 images. Otherwise it looks silly. Can't recall why I included File:C2020F3.2020-07-17.22.32.720p.ogv so instead I'd suggest going with the ISS one. Golden Gate Bridge has star trails and distorted nucleus.©Geni (talk) 19:05, 24 July 2020 (UTC)[reply]
I suggest to keep one image with sufficient context of the Big Dipper to demonstrate the relative size, like File:NEOWISE και Μεγάλη Άρκτος 0551.jpg. Or the real nice one at https://www.reddit.com/r/Astronomy/comments/huex8i/neowise_over_yosemite/ if permission can be obtained. On a similar note the conjunction with iota Ursae Majoris shown in File:C2020F3.P1023630.jpg has its own value (in fact the image closely resembles what I saw live in binoculars, so it can be said to demonstrate a view like many may have observed the comet live and without sophisticated equipment). Just note that the gallery shows it with a wrong caption (kappa instead of iota). Snherrmann (talk) 21:07, 25 July 2020 (UTC)[reply]
File:NEOWISE και Μεγάλη Άρκτος 0551.jpg or something like it is a good idea although size is very dependent on the exposure length use (and the amount of sky needed to be covered for this shot may limit our options). I think File:The comet C 2020 F3 NEOWISE set.gif covers what people might have seen (and human eyes shouldn't have thrown up a green head).©Geni (talk) 15:03, 26 July 2020 (UTC)[reply]
I disagree that the Croatia one is the best of the artsy photos. The San Francisco one is of higher resolution, has a nice sunrise going on, and features the comet more prominently. -- King of ♥ ♦ ♣ ♠ 20:20, 26 July 2020 (UTC)[reply]
San Francisco one has star trails and in general looks to have pushed the ISO a bit far.©Geni (talk) 11:49, 27 July 2020 (UTC)[reply]
Apples and oranges. The SF one is available at 4x the linear resolution (18x the square resolution) of the Croatia one - flaws are very easy to hide when you downsample that much. -- King of ♥ ♦ ♣ ♠ 13:27, 27 July 2020 (UTC)[reply]
I prefer fruit without star trails. We also have File:Comet NEOWISE over Odessa, Ukraine 01.jpg.©Geni (talk) 14:27, 29 July 2020 (UTC)[reply]
Again: you don't know if the Ukraine or Croatia photos have star trails, because the resolution is so low. At equivalent size I can't see star trails on the SF photo either. -- King of ♥ ♦ ♣ ♠ 15:35, 29 July 2020 (UTC)[reply]
Star trails are visible in at the Ukraine scale and partially visible at the Croatia scale. Which in the case of the Croatia scale image is what you would expect. We have meta data. Since the earth rotates at a constant speed and none of the images appear to have used a tracking mount the star trails are calculatable. Croatia was taken with a shorter lens even after adjusting for sensor size. Both were at 4 seconds.©Geni (talk) 17:16, 29 July 2020 (UTC)[reply]
105mm (equivalent) vs. 120mm with the same shutter speed means that the trails on one are 14% longer than on the other. Does that difference really matter? -- King of ♥ ♦ ♣ ♠ 17:32, 29 July 2020 (UTC)[reply]
Assuming the photos were taken at the respective camera's native resolutions about 1.5 pixels worth. So if Croatia is scaled to the size where they don't quite show then golden gate will need a little more downscaling. Odessa was at 80mm but we don't have the other data. If you insist we can go with golden gate but we will still be looking for a better artistic shot.©Geni (talk) 19:25, 30 July 2020 (UTC)[reply]
For a particular shutter speed, the length of star trails will be fixed as a function of the size of the comet. Anyways, I don't see the need to restrict ourselves to four anyways. The current gallery has too many, but we can easily cut it in half by removing all the ones where the comet is small and there is no interesting foreground or color in the sky. -- King of ♥ ♦ ♣ ♠ 20:38, 30 July 2020 (UTC)[reply]
No. Comet size is driven by the full exposure triangle. Aperture and ISO also matter. Going above 4 may push you into a second line on lower res monitors. Anyone know how many you can fit on a 1080p display?©Geni (talk) 11:18, 31 July 2020 (UTC)[reply]

My 1440p display can fit 9 per row, so I'd imagine something like 6 or 7 for 1080p. -- King of ♥ ♦ ♣ ♠ 12:51, 31 July 2020 (UTC)[reply]

Resulting gallery2

Resulting gallery3

Will switching to this tomorrow morning unless there are further objections.©Geni (talk) 16:17, 31 July 2020 (UTC)[reply]

File:Comet Neowise over Joshua Tree National Park.png is also a good one to keep; Joshua Tree National Park is a well-known dark-sky preserve, so there's an encyclopedic argument for its inclusion. -- King of ♥ ♦ ♣ ♠ 16:27, 31 July 2020 (UTC)[reply]
Noise, star trails, coma, hot pixels. For a dark sky site its not good.©Geni (talk) 04:41, 2 August 2020 (UTC)[reply]
The overall impression matters a lot. The comet is more prominent in this image than many of the other images. If you magnified those images to make the comet the same size, they would probably have worse quality. -- King of ♥ ♦ ♣ ♠ 04:51, 2 August 2020 (UTC)[reply]
The fact that Joshua Tree National park is a dark-sky preserve is not any kind of encyclopaedic argument for including a comet image taken from there. I see no reason to include it. I also do not see any reason why the four remaining gallery images need to be in a section called "gallery". They could be simply placed inline like normal images. Sankura (talk) 14:24, 4 August 2020 (UTC)[reply]

"...a few stars"?[edit]

Said stars are not visible in Comet C-2020 F3 (NEOWISE).gif, but that said, which stars are they?

kencf0618 (talk) 13:55, 23 July 2020 (UTC)[reply]

Requested move 24 July 2020[edit]

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

Moved as proposed. There is a narrow but well-supported consensus for the common name; contentions that another object of this time might be discovered, rendering the title ambiguous, are speculative, and in any case are scotched by the fact that the proposed title already redirects to this subject, indicating an expectation that absent unknowable future developments it will be the primary topic of the proposed title. BD2412 T 00:28, 8 September 2020 (UTC)[reply]

C/2020 F3 (NEOWISE) → Comet NEOWISE – This comet can be referred to by this name because this is the most notable comet that NEOWISE discovered and that title already redirects here. Interstellarity (talk) 19:27, 24 July 2020 (UTC) —Relisting. Steel1943 (talk) 08:29, 12 August 2020 (UTC)[reply]

Comment: I would say NEOWISE straddles the definition of a great comet, but it not up to Wikipedia to make that distinction. I will be curious what peer-reviewed papers say with the advantage of hindsight. -- 19:50, 24 July 2020 (UTC)
Would be surprised if they great comet-ed this one, worth seeing but can't just walk out the door and see the thing (even with binocs and knowing where it approx. is it takes a few seconds to locate). And Kheider, thanks for your good work on the page. Randy Kryn (talk) 19:58, 24 July 2020 (UTC)[reply]
NEOWISE was very impressive for about one week, but the definition of a great comet can be as fuzzy as the object itself. I guess if it was truly great there would be little debate about it. -- Kheider (talk) 20:05, 24 July 2020 (UTC)[reply]
There will not be a better known NEOWISE as easily visible naked eye comets are rare. -- Kheider (talk) 17:28, 31 July 2020 (UTC)[reply]
The future is not predictable. Another bright NEOWISE is certainly possible. Sankura (talk) 18:10, 1 August 2020 (UTC)[reply]
Extremely unlikely. Certain things can be ruled out with high confidence as the discovery rate by NEOWISE is no where near other surveys. -- Kheider (talk) 00:29, 2 August 2020 (UTC)[reply]
The discovery rate has no bearing on how bright the discovered comets might become. Sankura (talk) 08:05, 2 August 2020 (UTC)[reply]
The low discovery rate of NEOWISE has a lot do with the odds of discovering an "easily visible naked eye comet". -- Kheider (talk) 11:12, 2 August 2020 (UTC)[reply]
But it has nothing to do with which NEOWISE comet will be the brightest. Sankura (talk) 11:46, 2 August 2020 (UTC)[reply]
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

change of orbit[edit]

In this article, it sounds like the change of orbital period occurred because of the comet's close approach to the Sun. That is incorrect. An object in orbit around the Sun will keep the same orbit unless it is perturbed by the gravity of another object. For Comet NEOWISE, the perturbing object is Jupiter, which it passed within 1 AU of. So it is the Jupiter approach, not the Sun approach, that changed the comet's orbit. -- Ems57fcva

Closest approach to Jupiter will occur 20 September 2020 at 4.2 AU in part due the extreme inclination of the orbit. It is just better to say that the orbit will change while in the planetary region which is true for all comets. -- Kheider (talk) 01:36, 3 August 2020 (UTC)[reply]
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