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==Arabic==
==Arabic==
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: If Deneb is a spectral class of A (not O or B), then it may be confusing to call it a Blue Giant, especially along with the reference that it is a short-lived star. O and B are Blue Giants, A is more a White Giant with a blue tinge. Blue Giants, if my understanding is correct, is a term used for O and B classes, not A classes. If my understanding is correct, the text referencing Deneb as a Blue Giant should probably be clarified. Tesseract501 June 6 2006.
: If Deneb is a spectral class of A (not O or B), then it may be confusing to call it a Blue Giant, especially along with the reference that it is a short-lived star. O and B are Blue Giants, A is more a White Giant with a blue tinge. Blue Giants, if my understanding is correct, is a term used for O and B classes, not A classes. If my understanding is correct, the text referencing Deneb as a Blue Giant should probably be clarified. Tesseract501 June 6 2006.


== Adopted? ==
== Absolute magnitude estimate ==


"adopted distance". This is a peculiar undefined phrase that I can't find anywhere on the internet. The definition of "adopted" does not include a meaning that would apply to distance. How does one "adopt" a measurement? I'm guessing, from context, that it is an agreed-upon distance because the actual distance is not precisely known. But this odd-ball jargon should be linked to a proper explanation.[[User:77Mike77|77Mike77]] ([[User talk:77Mike77|talk]]) 15:10, 10 November 2020 (UTC)
Why is the value -8.73 given to two decimal places, while later in the text both distance and luminosity are uncertain by a factor of four? (which is almost two magnitudes). Wouldn't it be better to say "about -8.5" and leave it there? [[User:Alfio|Alfio]] 12:14, 21 August 2006 (UTC)
:The term is widespread, at least in the scientific literature. The distance of most stars is not precisely and reliably known. Different authors publish different distances at various times, perhaps derived using different methods or just from different observations. When an astronomer is working on a particular star and needs a distance, they will usually just "adopt" a previously-published one rather than go out and try to reinvent the wheel. The adopted distance might just be any old random distance if it is not critical to their own research, or a relatively recent result that is considered reliable, or might be a careful statistical weighting of all the available research if it is important to be as precise as possible. I'm not sure you'll find a suitable article to link this to; it would be little more than a dictionary definition. Is an adjective and a noun going to be unclear to most people? [[User:Lithopsian|Lithopsian]] ([[User talk:Lithopsian|talk]]) 15:43, 10 November 2020 (UTC)
:I've changed the page. [[User:Alfio|Alfio]] 22:30, 2 September 2006 (UTC)


Thanks, that was my guess, but it's widespread use "in the literature" equates to the phrase being jargon. To most people, "adopt" means, e.g. "adopt a stray cat", and this accords with both the dictionary definition and common usage. To "adopt" a measurement is something that makes no dictionary sense, nor common sense. So I was wondering whether one could state with confidence that Deneb is 2600 ly away. Elsewhere, I read that the calculated distance ranges from about 2400 to 2800, depending on the technique, so I see that 2600 is like an average, or a compromise. Probably most people interested in Deneb would guess that much, so it's not a big deal to me, but "adopted" does come across as jargony, given that this is supposed to be a general encyclopedia, not an article targeting experts. "Approximate" might be a less jargony choice, but that's just my opinion.[[User:77Mike77|77Mike77]] ([[User talk:77Mike77|talk]]) 22:03, 10 November 2020 (UTC)
: Thanks to Hevron for changing the value for absolute magnitude in the article to match that in the Starbox sidebar, -6.95. This value would seem to be derived from the data in the 2008 Apellániz et al. article (reference 3) which gives the parallax of Deneb as 2.29 mas, but with an uncertainty of more than 10% (±0.32). This parallax value may be used to calculate a “most likely” absolute magnitude value of -6.95, but it seems appropriate to round this off to 2 significant figures, i.e. -7.0, to reflect the considerable uncertainty in distance. The value has been tweaked in both the Starbox sidebar and the main text, and the text has been reworded slightly to put somewhat more emphasis on the rather large uncertainty band of both distance and absolute magnitude. [[User:Piperh|Piperh]] ([[User talk:Piperh|talk]]) 00:15, 23 August 2010 (UTC)
:From dictionary.com: "to choose or take as one's own; make one's own by selection or assent". It is the first meaning in that dictionary, not always the first meaning in others, but a standard meaning. Not really much different to adopting a stray cat or even a baby, but less paperwork :) [[User:Lithopsian|Lithopsian]] ([[User talk:Lithopsian|talk]]) 15:45, 11 November 2020 (UTC)


It's still not very scientific. You could adopt the identity of Peter Pan, but that doesn't mean you are. The word "adopted distance" suggests that the distance was plucked out of a buffet of random distances, and may therefore have nothing to do with the actual distance. I'm not saying that the meaning of the word "adopted" cannot be stretched out enough to provide an excuse for using the shop-talk jargon phrase "adopted distance", which is apparently what you are fixated on doing. I am pointing out that it IS insider jargon that leaves the non-specialist reader wondering if the number 2600 is reliable, or just pulled out of a hat. In other words, this article is NOT encylopedic, because it locks out the majority of readers who are not already specialists. Too many wikipedia contributors seem unable to grasp the meaning of the word "encyclopedia". I only looked at this specialist's shop-talk article because the search engines put Wikipedia at the top. In future, I'll skip to the next one as a time-saver. The other articles I read were better than this one, and are more suitable for reading by the general public, and more informative.[[User:77Mike77|77Mike77]] ([[User talk:77Mike77|talk]]) 16:26, 11 November 2020 (UTC)
:: (Belatedly) This [http://arxiv.org/pdf/0712.0040v1.pdf 2009 paper by Schiller] gives the luminosity as a whopping 196,000 and absolute magnitude of -8.38 (!) - but doesn't give light year distance in it. Would gel with a further distance and doesn't hipparcos have one somewhere of 3000 light years? Anyway, might be good to lay all the evidence out. [[User:Casliber|Casliber]] ([[User talk:Casliber|talk]] '''·''' [[Special:Contributions/Casliber|contribs]]) 20:38, 30 June 2012 (UTC)
:As a scientific method, "adoption" could well be plucking out a random distance. Or it may be a considered choosing of the best available distance. In many cases it will be better to reference the original derivation of a distance, although an adoption might help to indicate a consensus value. If you want to link it to something, go ahead, but linking individual words with a trivial meaning isn't usually helpful. Maybe there could or should be (or is?) an article about the scientific concept, but I suspect it wouldn't amount to much. [[Adoption (disambiguation)]] doesn't mention it, perhaps it should, but again where would it link to? [[User:Lithopsian|Lithopsian]] ([[User talk:Lithopsian|talk]]) 16:43, 11 November 2020 (UTC)
:On a more general point: are you just here to complain or do you have some helpful input? There is nothing to stop you editing the article yourself if you think it needs to be improved. It is a wiki after all. [[User:Lithopsian|Lithopsian]] ([[User talk:Lithopsian|talk]]) 16:45, 11 November 2020 (UTC)


I think "approximate distance" would be less jargony, and convey the same information. I'm reluctant to edit it myself, because usually my edits are reverted. I'm not complaining, just making a constructive suggestion. Basically, I think it is very cool to be interested in astronomy, and no offence was intended. I'm still in awe of how huge Deneb is, and how it is so bright at such a distance.[[User:77Mike77|77Mike77]] ([[User talk:77Mike77|talk]]) 17:38, 11 November 2020 (UTC)
:: The star is far enough away that the [[extinction (astronomy)|extinction]] may be pretty significant. I just added a sentence to that article about extinction reducing the magnitude by around 1.8 magnitudes per kiloparsec (in the [[V band]]) for stars near the galactic plane, which this star is. In this case though, the paper linked by Casliber only gives an A<sub>V</sub> of 0.11, so obviously YMMV. Regards, [[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 21:18, 30 June 2012 (UTC)


== Uncertainty in luminosity ==
:: The paper gives a distance of 802 parsecs. I have included this in the article. You can add light years too if you want. [[User:Lithopsian|Lithopsian]] ([[User talk:Lithopsian|talk]]) 23:55, 30 June 2012 (UTC)
::: Dang, I missed that - I did scan the article for mention of light years....great. [[User:Casliber|Casliber]] ([[User talk:Casliber|talk]] '''·''' [[Special:Contributions/Casliber|contribs]]) 23:59, 30 June 2012 (UTC)


The article says that the distance and hence intrinsic luminosity is poorly known. The distance is given as
:::: [http://adsabs.harvard.edu/cgi-bin/nph-bib_query?2010A%26A...521A...5C&db_key=AST Chesneau et al (2010:p. 9)] point out that the van Leeuwen (2007) value for distance is considerably smaller at {{nowrap|432 ± 61 pc}}, which results in a luminosity of 55,100 L<sub>☉</sub>. You might want to just list both values. Regards, [[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 21:14, 3 July 2012 (UTC)
2615±215 light years implying an uncertainty in luminosity of ((2615+215)/(2615-215))² = 1.39
::::: The Schiller paper lists within it previous attempts to examine Deneb's size, distance and luminosity. I think the best approach is to read, digest and then regurgitate them in an orderly fashion on the page as I am sure they will be quite fascinating (maybe not to the detail of [[Betelgeuse]] but still a fairly interesting and long tale). I am warming to the idea of donig it myself, but am not crash-hot on the physics. If anyone is keen for a collaboration, I am - on the farthest first magnitude star....[[User:Casliber|Casliber]] ([[User talk:Casliber|talk]] '''·''' [[Special:Contributions/Casliber|contribs]]) 00:47, 4 July 2012 (UTC)
But Deneb is said to be 55000 - 196000 times as bright as the sun where 196000/55000 = 3.564.
:::::: Yes, it's probably worth expanding the current paragraph on the topic. Thanks. Regards, [[User:RJHall|RJH]] ([[User_talk:RJHall|''talk'']]) 17:24, 4 July 2012 (UTC)
Are there other factors that contribute to the uncertainty in luminosity? [[User:Drhex|Drhex]] ([[User talk:Drhex|talk]]) 08:01, 23 November 2024 (UTC)

== Distance in Light Years ==

Why is the distance given here thousands of light years different from the one in [[List_of_stars_in_Cygnus]] and [[List_of_brightest_stars]]?
[[User:Xorthan|Xorthan]] ([[User talk:Xorthan|talk]]) 17:52, 3 December 2008 (UTC)

To add to Xorthan's comment above, the Hipparcos star catalogue cited in the article claims a distance of 3,229ly [http://www.heavens-above.com/hipentry.asp?hip=102098], as does the Stellarium planisphere software.
[[User:Clackpot|Clackpot]] ([[User talk:Clackpot|talk]]) 18:07, 31 May 2010 (UTC)

:"Distance 802+66pc" seems to be a mistake. Possibly, plus or minus should be used. <span style="font-size: smaller;" class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/78.105.0.33|78.105.0.33]] ([[User talk:78.105.0.33|talk]]) 13:56, 6 September 2012 (UTC)</span><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->

== Comparison ==

[[Image:Deneb Sun comparison.svg|thumb|Estimates for Deneb's radius range from 200 to 300 times [[solar radius|that of the Sun]]. This is the approximate size of the Sun (right) relative to Deneb.]]
Unless someone can provide a reference for the ~250 solar radii figure, this image (which uses this number) should not go in the article as it is potentially-misleading. The Kaler reference uses ~110 solar radii, so I've updated the article to use that. [[User:Icalanise|Icalanise]] ([[User talk:Icalanise|talk]]) 17:52, 25 July 2011 (UTC)

Latest revision as of 13:16, 23 November 2024

Arabic

[edit]

I suggest that the Arabic meaning of Deneb, and the associated mythology, be added to this article.

Blue Giant

[edit]

I got to this page by following a link from the Blue Giant article. Shouldn't the Deneb article mention that Deneb is a Blue Giant? This would seem to be important information.

If Deneb is a spectral class of A (not O or B), then it may be confusing to call it a Blue Giant, especially along with the reference that it is a short-lived star. O and B are Blue Giants, A is more a White Giant with a blue tinge. Blue Giants, if my understanding is correct, is a term used for O and B classes, not A classes. If my understanding is correct, the text referencing Deneb as a Blue Giant should probably be clarified. Tesseract501 June 6 2006.

Adopted?

[edit]

"adopted distance". This is a peculiar undefined phrase that I can't find anywhere on the internet. The definition of "adopted" does not include a meaning that would apply to distance. How does one "adopt" a measurement? I'm guessing, from context, that it is an agreed-upon distance because the actual distance is not precisely known. But this odd-ball jargon should be linked to a proper explanation.77Mike77 (talk) 15:10, 10 November 2020 (UTC)[reply]

The term is widespread, at least in the scientific literature. The distance of most stars is not precisely and reliably known. Different authors publish different distances at various times, perhaps derived using different methods or just from different observations. When an astronomer is working on a particular star and needs a distance, they will usually just "adopt" a previously-published one rather than go out and try to reinvent the wheel. The adopted distance might just be any old random distance if it is not critical to their own research, or a relatively recent result that is considered reliable, or might be a careful statistical weighting of all the available research if it is important to be as precise as possible. I'm not sure you'll find a suitable article to link this to; it would be little more than a dictionary definition. Is an adjective and a noun going to be unclear to most people? Lithopsian (talk) 15:43, 10 November 2020 (UTC)[reply]

Thanks, that was my guess, but it's widespread use "in the literature" equates to the phrase being jargon. To most people, "adopt" means, e.g. "adopt a stray cat", and this accords with both the dictionary definition and common usage. To "adopt" a measurement is something that makes no dictionary sense, nor common sense. So I was wondering whether one could state with confidence that Deneb is 2600 ly away. Elsewhere, I read that the calculated distance ranges from about 2400 to 2800, depending on the technique, so I see that 2600 is like an average, or a compromise. Probably most people interested in Deneb would guess that much, so it's not a big deal to me, but "adopted" does come across as jargony, given that this is supposed to be a general encyclopedia, not an article targeting experts. "Approximate" might be a less jargony choice, but that's just my opinion.77Mike77 (talk) 22:03, 10 November 2020 (UTC)[reply]

From dictionary.com: "to choose or take as one's own; make one's own by selection or assent". It is the first meaning in that dictionary, not always the first meaning in others, but a standard meaning. Not really much different to adopting a stray cat or even a baby, but less paperwork :) Lithopsian (talk) 15:45, 11 November 2020 (UTC)[reply]

It's still not very scientific. You could adopt the identity of Peter Pan, but that doesn't mean you are. The word "adopted distance" suggests that the distance was plucked out of a buffet of random distances, and may therefore have nothing to do with the actual distance. I'm not saying that the meaning of the word "adopted" cannot be stretched out enough to provide an excuse for using the shop-talk jargon phrase "adopted distance", which is apparently what you are fixated on doing. I am pointing out that it IS insider jargon that leaves the non-specialist reader wondering if the number 2600 is reliable, or just pulled out of a hat. In other words, this article is NOT encylopedic, because it locks out the majority of readers who are not already specialists. Too many wikipedia contributors seem unable to grasp the meaning of the word "encyclopedia". I only looked at this specialist's shop-talk article because the search engines put Wikipedia at the top. In future, I'll skip to the next one as a time-saver. The other articles I read were better than this one, and are more suitable for reading by the general public, and more informative.77Mike77 (talk) 16:26, 11 November 2020 (UTC)[reply]

As a scientific method, "adoption" could well be plucking out a random distance. Or it may be a considered choosing of the best available distance. In many cases it will be better to reference the original derivation of a distance, although an adoption might help to indicate a consensus value. If you want to link it to something, go ahead, but linking individual words with a trivial meaning isn't usually helpful. Maybe there could or should be (or is?) an article about the scientific concept, but I suspect it wouldn't amount to much. Adoption (disambiguation) doesn't mention it, perhaps it should, but again where would it link to? Lithopsian (talk) 16:43, 11 November 2020 (UTC)[reply]
On a more general point: are you just here to complain or do you have some helpful input? There is nothing to stop you editing the article yourself if you think it needs to be improved. It is a wiki after all. Lithopsian (talk) 16:45, 11 November 2020 (UTC)[reply]

I think "approximate distance" would be less jargony, and convey the same information. I'm reluctant to edit it myself, because usually my edits are reverted. I'm not complaining, just making a constructive suggestion. Basically, I think it is very cool to be interested in astronomy, and no offence was intended. I'm still in awe of how huge Deneb is, and how it is so bright at such a distance.77Mike77 (talk) 17:38, 11 November 2020 (UTC)[reply]

Uncertainty in luminosity

[edit]

The article says that the distance and hence intrinsic luminosity is poorly known. The distance is given as 2615±215 light years implying an uncertainty in luminosity of ((2615+215)/(2615-215))² = 1.39 But Deneb is said to be 55000 - 196000 times as bright as the sun where 196000/55000 = 3.564. Are there other factors that contribute to the uncertainty in luminosity? Drhex (talk) 08:01, 23 November 2024 (UTC)[reply]