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Figure
edit--67.133.79.98 14:46, 27 October 2006 (UTC)The figure for the semimajor axis of the companion, given as 5 AU, is obviously in error. Here's why: a = cuberoot of the total mass times the period squared (say, 30 years). For any reasonable value of M (which can hardly be less than 10 times our sun's, given the luminosity of Polaris A), the size of the orbit comes out at about the distance of Pluto from the sun--not Jupiter!--for having extra mass in the system, causes them to revolve FASTER. The best approximation[18] was made using the leading edge of the constellation Ursa Major as a point of reference. The leading edge (consisting of the star Dubhe) is referenced to a clock face and the azimuth of Polaris worked out for different latitudes. Addendum. When i wrote the foregoing, i didn't have precise figures for Polaris's mass. By the Cepheid relation M = .58 + .24 log P (in days) the mass of the primary should be about 5.29 times the Sun (not 8 to 10, which is more typical of a F-type supergiant of this luminosity). Assuming for the moment that the unseen companion is about 300 times dimmer than the visible primary, this comes out to a mass ratio of about Ma/Ma+Mb of 0.75; & the semimajor axis is 18.35 Astronomical Units (or 18.7, if you use Burnham's period of 30.5 years)...more like the distance of Neptune. (Its eccentricity takes the two stars from 7 to 29 AU separation.) The displacement of the primary amounts to about 4.58 AU, or 426 million miles, presumably the source of the quoted figures (with 290 million miles, given by Burnham, the mass of the companion becomes very small indeed). But this is a small portion of the entire orbit.
This is a good subject for calculating derived figures on, for the values derived from Cepheid equations can be tallied with the observed type F3 main sequence third star; thus the range of distances possible is fairly narrow, in comparison with many other supergiant stars, e.g. Canopus or Rigel.
Exterior Cosmology
editIs is known yet whether the Earth rotates in a Galactic or Exterior Object cosmology? That can be boiled down to whether the Earth's axis is stable in relation to the Milky Way Galaxy or to the exterior galaxies such as Andromeda and the zillions of others.
--
SyntheticET (talk) 17:45, 17 November 2007 (UTC)
- Wow. There is a science of cosmology, besides the cosmological fantasies that go along with any average Creator of the Universe myth, but Fantasiality.com probably has a corner on both the choices you're considering. If you're not willing accept that any point you choose to regard as the navel of the universe can be shown, by restricting which infinitely large volume of the universe you choose to disregard, to be valid. Sorry, kid; it's a shame that they never tell you, when you sign up, about Absolutes being a fairy tale.
--Jerzy•t 02:28, 21 May 2018 (UTC)
Dominance of the North?
editI once read that a major factor contributing to the dominance of the northern hemisphere in such activities as ocean navigation and widespread colonization and travel was due to the fact that there is a North Star, but no South Star. Has anyone else heard this? --Golbez 21:31, Sep 27, 2004 (UTC)
- Nope I haven't seen that one, but see also Guns, Germs, and Steel. — RJH 20:01, 17 January 2006 (UTC)
I could figure out the point in the sky thats south based on the constellations in one night of looking up there. Ancient people have figured out things a lot more complicated than that.
It is definitely nothing to do with the pole star - it's quite simple there is far more land and resources in the Northern hemisphere and so there have always been far more people in the Northern hemisphere. In any case, around the time of Christ there was no bright star within 5° of the pole whereas Miaplacidus was quite close to the South pole --AssegaiAli 18:05, 9 October 2007 (UTC)
Join this article?
editThis article is of the same subject as North star, and Pole star. i think it would be good to join these articles.
- above by 12:54, user:Gxojo at 12:54, 28 Jan 2005
- No, North Star is not about Alpha Ursae Minoris per se. It is about all North Stars, such as will be Vega in the future. And pole star covers both North Star and South Star (or should). Polaris, inappropriately named, covers only Alpha Ursae Minoris. 132.205.15.43 04:00, 1 Feb 2005 (UTC)
Visibility from the Southern Hemisphere
editPolaris can be visible from locations near the equator in the southern hemisphere. Polaris is about 0.75° from true north. At an elevation of 3km, horizon dip is 1.75°, and atmospheric refraction can be good for another 0.5°, depending on conditions. Adding these up, Polaris can rise over the horizon at locations as far as 3°S.
At 3km elevation, atmospheric extinction at 3° from the horizon can be as low as 2 magnitudes, and as low as 5 magnitudes at the horizon itself. Under these near perfect circumstances, Polaris could be a naked eye magnitude 4 at (or just south of) the equator, and up to magnitude 7 at 3°S. — Preceding unsigned comment added by 38.117.102.236 (talk) 12:24, 18 April 2012 (UTC)
Distance from the north pole
editShouldn't it be 42', not 42" ? Or what exactly does " mean (compare the coordinates)? Otoomet 16:45, 2 July 2006 (UTC)
- Oops, that's embarrassing. I actually wrongified that part of the article months ago. The HTML should have read ′ instead of ″. I've fixed it. -- Xerxes 20:58, 2 July 2006 (UTC)
If the declination is 89° 15′ 51″ (as stated in the table under the figure), then shouldn't the distance from the north pole be 90° - ( 89° 15′ 51″ ), i.e. just over 44' and not 42' as stated in the article? What am I missing? Jbuddenh (talk) 17:02, 28 May 2008 (UTC)
'It is very close to the north celestial pole (42′ away as of 2006)'. . .'At present, Polaris is 0.7° away from the pole of rotation (1.4 times the Moon disc)'.
1.4 times the moon's diameter is a HUGE optical distance, I never realised it was that far out - I don't think that this can be called 'very close' at all - I had always assumed that it was identical for all practical purposes, as I think most people do - this is very important and ought to be emphasised - at the very least changed to 'about one and a half moon diameters from the north celestial pole'.
81.100.161.66 (talk) 22:17, 6 October 2009 (UTC)
Polaris Ab
editThis 10 Jan 2006 news release contained material an amateur like me would be interested to read in the article:
- "The companion proved to be less than two-tenths of an arcsecond from Polaris — an incredibly tiny angle equivalent to the apparent diameter of a quarter located 19 miles away."
- By watching the companion star in its 30-year orbit, astronomers expect to learn not only the stars' orbits but also their masses, valuable because it is the nearest Cepheid variable, the brightness variations of which are used to measure the distances of galaxies and the expansion rate of the universe.
General complaints
edit"Rust in Peace...Polaris". Is a reference to the nuclear missile system, and nothing to do with the star apart from the missile system beign named after it, which is just daft.
From the linked article on the album:-
"I was driving home from Elsanon... um, Lake Elsanon. I was tailgating somebody, racing down the freeway, and I saw this bumper sticker on their car and it said... you know, this tongue in cheek stuff like, 'One nuclear bomb could ruin your whole day,' and then I looked on the other side and it said, 'May all your nuclear weapons rust in peace,' and I'm goin', ' 'Rust in Peace.' Damn, that's a good title.' And I'm thinkin' like, 'What do they mean, rust in peace?' I could just see it now - all these warheads sittin' there, stockpiled somewhere like Seal Beach, you know, all covered with rust 'n' stuff with kids out there spray-painting the stuff, you know." - Dave Mustaine, the band's main songwriter.
Obviously and from the horses mouth, nothing to do with the star. Perhaps the song should be linked in an article about bumper stickers?
As for "In the song, Polaris is the name of a disease." lyrics from the song:- "I am a nuclear murderer I am Polaris Ready to pounce at the touch of a button"
"Load Star" Load of BS. It was Lode only, until the bloody educational collapse of the late 20th century meant that no-one can spell anything anymore. Lodestone points to the lode star, a load of stone just sits there.
While I'm on it, the diameter of quarters is only a useful example to people in the US who regularly see quarters. 195.27.13.34 13:13, 8 June 2007 (UTC)
Star chart for North Pole
editI suggest it would be useful to draw a diagram of the stars near celesial north pole, and trace a rough path of the pole over time. --206.75.168.235 05:15, 2 August 2007 (UTC) :( Actually, I'm Kevinkor2 (talk · contribs) but too lazy to log in. ):
Culture section
editDoes a list of bands really belong in an encyclopedia article about an astronomical object? Keeping in mind that Wikipedia is not a trivia collection, are there any reasons to keep it? Feezo (Talk) 19:08, 19 August 2007 (UTC)
More references
editI think we need more references to eventually reach FA status with this article. RJFJR (talk) 16:59, 3 January 2008 (UTC)
Ptolemy?
editI'm confused, the introduction says that Polaris was first noticed by William Herschel in the 18th century, but then refers to the star's rapid evolution from the time when Ptolemy first noticed it. Who noticed it first? —Preceding unsigned comment added by 83.28.18.214 (talk) 09:10, 8 February 2008 (UTC)
The introduction says "Polaris B" was first noticed by William Herschel, not that Polaris was first noticed by him. Ptolemy was certainly NOT the first to notice Polaris. It was certainly known to Hipparchus and no doubt to the Babylonian astronomers if not to the Sumerians at least 3 millennia before Ptolemy. However, at that time and even at the time of Christ, Polaris was NOT the closest star of similar magnitude to the Celestial north pole. Jbuddenh (talk) 17:32, 28 May 2008 (UTC)
I love the artist's impression
edit. . . but it's too YELLOW. A star that yellow would be a G5 or G8. The Polaris system would be stars of brilliant white with a trace of blue, like all F-types. (Bluish-yellow?) 68Kustom (talk) 11:51, 17 February 2008 (UTC)
- Try K5 or K8! —Preceding unsigned comment added by 216.191.157.146 (talk) 00:48, 27 December 2008 (UTC)
- Since when do F stars of any flavour have a hint of blue? And Polaris is a late F star, not much hotter than the sun. Hint of yellow perhaps, hint of blue definitely not. Lithopsian (talk) 16:36, 15 November 2012 (UTC)
Changing brightness?
editthis article says Polaris has been undergoing major unexplained changes in brightness over the years. Surely this is worth mentioning in the wiki article? http://www.physorg.com/news135871831.html vroman (talk) 18:20, 23 July 2008 (UTC)
I agree. Reference the research: [1] --Dupes (talk) 18:31, 25 July 2008 (UTC)
Relevance of Assyrian reference
editUnder "Pole star", there is " The antiquity of its use is attested by the fact that it is found represented on the earliest known Assyrian tablets. " I have two concerns about this statement. One, it's not referenced. Two, the earliest Assyrian tablets go back to c. 2000 BC (see the Assyria article). At this time, Polaris was nowhere near the North Pole, which was closer to Kochab or Thuban at that time. So the Assyrian reference is more likely to denote one of those two stars (if it refers to a pole star).
-Craig Heinke
Etymology?
editetymology (n): An account of the origin and historical development of a word.
Nowhere in the "Etymology and cultural significance" section of this article is the etymology of the name "Polaris" discussed or mentioned. I found out more about the etymology of the name by looking in a dictionary. From wiktionary: From Latin Stella polaris, "pole star" --66.69.248.6 (talk) 19:12, 28 March 2009 (UTC)
It's probably my misunderstanding, but is this a contradiction?
editIn the Pole Star section, it says:
At present, Polaris is 0.7° away from the pole of rotation
But in the article, "North Star" it says:
In 2006 Polaris was 42' from the north celestial pole
I assume the north celestial pole and pole of rotation to be the same, correct?
Thus, what is the problem here? One article says 0.7°, the other says 42'? I am inclined to go with 42 due to what the North Star article said about progression of pole stars. If the last pole star was in place 5,000 years ago, and the next pole star will be in place in 1,000 years, it makes sense that it must currently be further away from the pole.
Can someone help? —Preceding unsigned comment added by Harleh (talk • contribs) 03:23, 8 May 2009 (UTC)
- 0.7° is the same as 42 arcmin. So what, indeed, is the problem? Skeptic2 (talk) 11:53, 8 May 2009 (UTC)
Mormon folklore
editGiven that there is some minor Mormon folklore regarding Polaris and an alleged statement by Joseph Smith, Jr., but this is presented as if this is actually believed by Latter-day Saints. The next statement in this article then stretches credibility to the limit, which uses a Sunstone Magazine comic as evidence of an actual belief that the Lost 10 Tribes would return in flying saucers! This is ridiculous! The comic (if it actually exists as described, which has not been verified because specifics on the edition & page it appeared in are missing from the cite) is extending & exaggerating a folk notion to reductio ad absurdum, not documenting or describing an actual belief. That bullet point needs some major rework, or should just be removed altogether. -- 208.81.184.4 (talk) 17:38, 2 July 2009 (UTC)
- I was raised in the LDS Church and when I attended church in San Francisco in the 1950s, it was assumed by many that the Ten Lost Tribes went to Polaris (not to the northern parts of Earth) because of that statement by Joseph Smith and many people in church reasoned that the only way they could get back from Polaris was by flying saucers because in the 1950s everyone was talking about flying saucers (How else could they get back unless it was by either by using rocket ships or by teleportation?). Obviously it is not believed by all LDS people but it is believed by some and that is why the cartoon appeared in Sunstone Magazine. Even those who do believe it admit it is Mormon folklore and not official Mormon doctrine. Keraunos (talk) 01:35, 5 July 2009 (UTC)
"Yilduz" and Turkish
editYilduz is from the Turkish word for "star" (see Yildun).
I couldn't completely understand that part from the article, but the Turkish word for "star" is actually "yıldız". I think that part should be something like;
Yilduz is from the Turkish word "yıldız" for "star" (see Yildun).
to avoid misunderstandings.
However, I didn't want to edit it. If it is ok to edit it like this, don't wait for me to do it, and improve the section.
--ThoAppelsin (talk) 00:20, 15 August 2010 (UTC)
Due north twice a day
editThe article mentions that Polaris is due north twice a (sidereal) day (reminding me of the comment about a stopped clock), but that is true of every star, surely? I just don't think it is a useful statement, and I see it replicated in isolation in various other web pages lifted from WP. I realize it is here in the context of correction tables, but even then the statement would be "the correction is zero, twice a day", which I don't think would be a useful addition. Furthermore, the sentence beginning "the best approximation" seems little off; it might be better to say "traditionally, these tables have references Dubhe (etc)". Comments? David Brooks (talk) 19:24, 27 August 2010 (UTC)
- Correction: "due north twice a day" is true of a subset of stars, dependent on latitude, I realize. David Brooks (talk) 16:25, 28 August 2010 (UTC)
Which one is the variable?
editThe article doesn't quite explicitly say which star is the Cepheid variable. I take it that α UMI A is the variable one? --Dylan Thurston (talk) 00:08, 11 October 2010 (UTC)
Of course α UMi A is the variable!
-Alexrybak (talk) 12:28, 26 May 2011 (UTC)
- No "of course" about it. α UMi A is iself a spectroscopic binary. The primary is a supergiant Cepheid variable while the secondary is a main sequence star of approximately the same temperature but much lower luminosity, only a little brighter than the sun. The article completely fails to make this clear and there is great confusion between the various stars in the system, especially in the starbox. Lithopsian (talk) 17:46, 13 November 2012 (UTC)
Name
editα UMi needs a name. I suppose we name it "alarsa" (al+ursa).
-Alexrybak (talk) 12:35, 26 May 2011 (UTC)
- It's already got one: "Alruccabah" 220.255.1.60 (talk) 03:24, 3 July 2011 (UTC)
- Whether it has one or not, WP's role is to report what is verifiable via reliable sources. So not only would such an attempt be (justly) vigorously mocked, but also it would do discredit to our commitment to core principles.
--Jerzy•t 03:44, 21 May 2018 (UTC)
Confusing explanation?
editThe 'Role as a pole star' section of the article currently ends with:
"The best approximation[18] was made using the leading edge of the constellation Ursa Major as a point of reference. The leading edge (consisting of the star Dubhe) is referenced to a clock face and the azimuth of Polaris worked out for different latitudes.
How does an edge consist of a single star? What does "referencing to a clock face" require one to do? Moreover, reference 18 leads to an undocumented Excel spreadsheet which does not clarify the point.
Spectral type
editIn the overview of the spectral type F2 Polaris is mentioned, however in this article there is only a F3 star, but non F2. Can anyone check which statement is correct? — Preceding unsigned comment added by 62.217.41.124 (talk) 00:09, 3 October 2012 (UTC)
- Polaris, being α UMi A, is a close binary. However the primary α UMi Aa contributes almost all the light and is spectral type F7Ib. The spectroscopic secondary α UMi Ab is difficult to examine clearly but is approximately F6V. A more distant companion α UMi B is visible optically and has been known for a long time. Recent work gives it a spectral type of F3V. I have found recent papers deriving updated data for all three of these stars and will update the article shortly. Lithopsian (talk) 00:08, 14 November 2012 (UTC)
That artists impression ...
edit... is highly misleading. Polaris B is considerably brighter than the closer companion Polaris Ab, around half a magnitude in the V band. Presumably the image is supposed to be taken from a close vantage point and hence Polaris B is much more distant than Polaris Ab but there is no way to know that from the image or the description. Hence anyone viewing the image will come away with the impression that the close companion is a lot more luminous than the distant one. Lithopsian (talk) 00:42, 14 November 2012 (UTC)
Starbox
editI'm attempting to update the parameters for this star system, and want to clearly show things like spectral types, masses, etc. for three components: Aa, Ab, and B. The current starbox format does not seem up to the task. Would the starbox multi template work better? Or would that just lose me the orbital information? Lithopsian (talk) 16:32, 15 November 2012 (UTC)
- Maybe. α UMi C and α UMi D should also get their information. --Artman40 (talk) 23:55, 30 November 2012 (UTC)
- The starbox would be crazy wide :) I'm not aware of particularly good data for these components anyway, certainly not enough to fill a starbox. Here are the Simbad pages for C and D, pretty sparse: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%40317447&Name=CCDM%20J02319%2b8915C&submit=submit and http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%40317446&Name=CCDM%20J02319%2b8915D&submit=submit Lithopsian (talk) 00:09, 1 December 2012 (UTC)
- Maybe then something more like in Castor article? --Artman40 (talk) 05:27, 1 December 2012 (UTC)
- The starbox would be crazy wide :) I'm not aware of particularly good data for these components anyway, certainly not enough to fill a starbox. Here are the Simbad pages for C and D, pretty sparse: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%40317447&Name=CCDM%20J02319%2b8915C&submit=submit and http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%40317446&Name=CCDM%20J02319%2b8915D&submit=submit Lithopsian (talk) 00:09, 1 December 2012 (UTC)
Please review this
edit323 ly latest calculations.
Astronomers clash over the distance to the famed North Star
http://phys.org/news/2012-11-astronomers-clash-distance-famed-north.html — Preceding unsigned comment added by 109.242.59.163 (talk) 02:31, 4 December 2012 (UTC)
- Anyone who wants to reference this result, please use the arXiv preprint reference that I've already created (name=turner), hopefully to be replaced by the peer-reviewed journal when it is released. Lithopsian (talk) 12:19, 5 December 2012 (UTC)
- I'm never comfortable with papers that quote some relatively obscure or old results in support of their surprising new idea while ignoring recent and contradictory work. In this case, a method subject to a number of potential inaccuracies has been used to derive a distance that contradicts several different methods, some of which have a very low margin of error. For example, the Hipparcos parallax for such a close star ought to be highly accurate (even allowing for it being a supergiant star with companions), and results from studies of both the primary and companion have supported this distance. Remarkable claims require remarkable evidence and I don't see it yet. I'll scan some more papers and see if there is support for anything more than a brief comment about this distance calculation. Lithopsian (talk) 09:52, 4 December 2012 (UTC)
- I've slightly expanded the comments added by fotaun, mentioning why this is such an important piece of data. Although I'm a big fan of referencing recent work with the best equipment and most advanced models, this latest distance estimate still makes me very uncomfortable. Going back many decades, distance estimates tended to be closer to 100 parsecs than 130. There are many papers finding a distance in the 100-110 parsec range over the last 10-20 years, although a remarkably large number of them are by the same author quoting previous work by the same author (clearly an expert with a focus on this type of star). I just have a tinge of fear that this is repeatedly calculating the same value from the same models despite direct evidence that the models need a little tweak. The latest Turner paper derives a distance 30% lower than the previous value (130pc from Evans et al, Hipparcos, etc) , apparently supported by the same data: the expected luminosity of Polaris B as an F3 main sequence star. At a guess I would suggest that treating Polaris B as a zero-age main sequence (ZAMS) star could account for the discrepancy, since Polaris B is clearly not a ZAMS star. F-type stars increase in luminosity by over 50% by the end of core hydrogen burning, and this corresponds to about a 25% difference in the calculated distance. Lithopsian (talk) 12:19, 5 December 2012 (UTC)
- Thanks for your comments and working on this. Hopefully we can get some of your deeper understanding of this issue into the article. I added a new distance section to expound on this area. I look forward to your contributions! Fotaun (talk) 17:03, 5 December 2012 (UTC)
Relative apparent brightness
editMany people mistakenly believe that the North Star is the brightest star in the night sky. This may be because it's the only star they've ever heard of, and so they assume it must be the brightest. Anyway, I wanted to clarify this, although I don't really have a reference for "people mistakenly believe it's the brightest star." So added a phrase to the introduction saying it's the 45th brightest star in the night sky. (Wikipedia's List of brightest stars has it at number 46, but that's because they include the Sun in that list.) —MiguelMunoz (talk) 23:28, 7 August 2014 (UTC)
max Distance
editIn the box I found the value for max distance = 425 ly. Within the text body (chapter distance) it is 434 ly with the same reference (nr.7). Because I do not have access to that reference, can any one else decide, which value should be there? Sextant (talk) 15:05, 11 April 2016 (UTC)
Why α UMi ?
editIn the body of this article, why do we keep switching from the common name of Polaris to α UMi and back again? Confusing if you don't pick one and stick with it. Kortoso (talk) 21:25, 24 October 2016 (UTC)
- You are right. Have tried to change all that I can see to Polaris. Cas Liber (talk · contribs) 09:18, 25 October 2016 (UTC)
Image trouble
editUser:Tomruen added a starbox with a map image with Polaris circled in red with this edit. It's a nice improvement but unfortunately the circle was not placing in the correct position (at least under Firefox). I've removed the circle for now until the problem can be identified and fixed. Jason Quinn (talk) 17:36, 6 December 2016 (UTC)
- The HTML overlay method if placing a circle over an image is not reliable. I believe that the circle position is relative to the width of the starbox, not to the width of the image so it will move when the starbox width changes due to content changes or to the font and screen settings of a particular computer. There is a location mark template specifically provided to reliably place marks on images. Lithopsian (talk) 17:57, 6 December 2016 (UTC)
Toward Ending the Polaris Parallax Debate
editThe findings from the recent paper [Toward Ending the Polaris Parallax Debate: A Precise Distance to Our Nearest Cepheid from Gaia DR2] should be included in the article. Not only do they revise the distance to Polaris to 137.14+0.53
−0.52 pc which differs from the value cited in the article; with their interpretation of the physical properties of component B they go far beyond what has already been added about the distance measurement.Renerpho (talk) 00:11, 10 September 2018 (UTC)
Proper motion accurate?
editIf the proper motion stated in the article is correct RA: 44.48±0.11 mas/yr Dec.: −11.85±0.13 mas/yr, this yields a total angular speed of roughly 46 mas/yr this is slightly less than 1 degree this seems too high to be correct, I suspect someone has accidentally dropped sig figs. Someone with background knowledge please double check I'll do a little checking myself. NotAsian (talk) 04:39, 10 December 2018 (UTC)
- Using PPM star catalogue updated entry for proper motion, turns out I misunderstood mas however converting from arcseconds to mas yielded an increase on the Wikipedia value https://heasarc.gsfc.nasa.gov/db-perl/W3Browse/w3table.pl?tablehead=name%3Dppm&Action=More+Options NotAsian (talk) 05:16, 10 December 2018 (UTC)
- Why did you change to the PPM value? Old, old, old. Hipparcos is newer and far more accurate. The margin of error in the PPM values is comparable to the motion itself, Hipparcos more like ±1%. Gaia should be another order of magnitude more accurate, but Polaris is too bright for the standard measurement methods and I haven't seen any results published for it yet. Lithopsian (talk) 16:03, 10 December 2018 (UTC)
The age of the 3 stars seems suspect.
editThe age of the 3 stars seems suspect, almost certainly incorrect, opening up questions as to whether other stated data are equally untrustworthy. The age for all three stars is given as 70,000,000 years, which makes them all very very young, and yet they seem to be main-sequence stars and should be billions of years old. It would be common for stars from the same stellar nursery to have similar ages, but not likely for all three to have the same identical age. I looked at the stated source and found no mention of the stars' ages at all.
J with a B (talk) 21:10, 3 April 2021 (UTC)
- I looked at the stated source and found two mentions of the star's ages. The one in section 3.2.5 says how the figure of 70 million years was arrived at. By the way, the ages of main-sequence stars start from zero (by definition), and stars of the mass of Polaris Aa move off the main sequence after much less than a billion years. No action is required. 62.64.210.235 (talk) 20:14, 22 June 2021 (UTC)
- I noted that the reference given in the article for the age of 70 Myr is quite old and not suitable. There is more recent work on this system, which points to an age discrepancy between Polaris itself (the Cepheid) and its companion. People generally agree that the Cepheid is young (maybe 50 Myr), while the companions are several billion years old. Perhaps this is worth an update - but I'm not sure what is needed to do this. In include some recent references that discuss the age issue. - Aleks
- https://ui.adsabs.harvard.edu/abs/2021ASPC..529...72N/abstract
- https://ui.adsabs.harvard.edu/abs/2018A%26A...611L...7A/abstract
- https://ui.adsabs.harvard.edu/abs/2018ApJ...853...55B/abstract 2A00:23C7:6E14:1001:B525:88EA:C427:B95C (talk) 11:14, 7 October 2023 (UTC)
- 70 million years, as in the starbox, is hardly out of the accepted range; one of the sources you give works with 75 million years and the most recent suggests between 45 and 67 million years. I've used that source to update the component values in the starbox, but this subject should probably be discussed more (or at all!) in the body of the article. Lithopsian (talk) 14:09, 8 October 2023 (UTC)
"above"
editIn nearly any other article I would quickly edit the "scare quotes" out of a word, but in this particular case, they are apt.
Good work, Wikipedia editors. HiDrNick! 04:31, 15 August 2021 (UTC)
Image of Flux Nebula
editI do not believe that the image https://en.wikipedia.org/wiki/Polaris#/media/File:Integrated_Flux_Nebula_Surrounding_Polaris_-_Kush_Chandaria.jpg has anything to do with Polaris. It shows a two globular clusters, none of which should be in the neighborhood of Polaris. — Preceding unsigned comment added by 92.218.153.145 (talk) 18:51, 25 November 2021 (UTC)
- NGC 188. Lithopsian (talk) 14:34, 26 November 2021 (UTC)
- Is it nearby? -The Space Enthusiast (talk) 14:40, 26 November 2021 (UTC)
Distance
editThe article gives a number of distance estimates based on different papers and techniques. But in the distance section, it seems to imply the latest Gaia estimate of 447.6 ly is considered the most reliable. Am I understanding this correctly, or is there still dispute? If that result is considered definitive, then I guess a distance section is not really needed. LastDodo (talk) 21:09, 27 November 2021 (UTC)
I deleted the last sentence in the Distance section: "Polaris has long been important for the cosmic distance ladder because, prior to Gaia, it was the only Cepheid variable for which direct distance data existed, which had a ripple effect on distance measurements that use this "ruler".[2]" Polaris is not the only Cepheid variable for which direct distance data existed prior to Gaia; [1] gives examples of 9 from HST. And it's importance in the cosmic distance ladder is mentioned in the first paragraph of this section.~~CaptainJoy6~~ — Preceding unsigned comment added by CaptainJoy6 (talk • contribs) 13:12, 5 March 2022 (UTC)
Observational history
editThe section Observational history currently only shows a table listing a selection of star catalogues/atlases which include (or do not include) Polaris and nothing else. What is the use of this section?
At most one can infer that every major star catalogue/atlas lists/shows Polaris with the exception of some 17th-century star catalogues which only list the stars around the celestial south pole. The Nasir al-Din al-Tusi entry is misleading at best as the Zij-i Ilkhani in fact contains two star catalogues: a comprehensive catalogue based on the Almagest (which of course includes Polaris) and a very short star catalogue that does not include Polaris.
Are there any pressing reasons why we should keep this table or section? AstroLynx (talk) 10:40, 25 August 2022 (UTC)
- Nearly a month ago I questioned the usefulness of the section Observational history and proposed to delete it. So far, no-one has responded to this proposal.
- In a week from now, unless someone comes with a cogent reason why we should keep it, I will delete it. AstroLynx (talk) 08:33, 22 September 2022 (UTC)
- The section adds very little to the article. I have no objection to its removal. TowardsTheLight (talk) 09:18, 22 September 2022 (UTC)
- I think removing it is a good idea. The true "Observational history" is that every person in the northern hemisphere who has looked north on a clear night has seen it. PopePompus (talk) 11:22, 22 September 2022 (UTC)
- Thanks for the input – as the ayes have it, I will delete it. AstroLynx (talk) 08:30, 29 September 2022 (UTC)
Polaris Ab is understudied
editI was making a personal star catalog, and in my choice I wanted to make Polaris the first star in the list. Unluckily though, it turned out that Polaris Ab had much less information than any of the other stars, leading me to write N/A in the temperature and age category. 197.156.77.134 (talk) 08:53, 7 January 2023 (UTC)
Age (and distance)
editBeyond my competence, but someone might decide whether to add info from this article: https://www.scientificamerican.com/article/how-old-is-the-north-star-the-answer-could-change-our-maps-of-the-cosmos/
Essentially it claims that the star is much older than previously thought (2 billion years), giving a possible mechanism, but no evidence that I can see. It's also mixed up with the question of the distance. HenryFlower 14:43, 1 June 2024 (UTC)