![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 |
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. Icalanise ( talk) 17:52, 25 July 2011 (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? Alfio 12:14, 21 August 2006 (UTC)
The article states that "Even assuming the lowest estimates of distance and luminosity, Deneb is the brightest and most distant of the first magnitude stars." This is a bit misleading, since "first magnitude stars" ( technically, those between 0.51 and 1.50 apparent magnitude) is a bit obscure and even lowest estimates of its distance place it closer than δ CMa, which is has an apparent magnitude of 1.83. — Aldaron • T/ C 22:45, 15 October 2012 (UTC)
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? 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 [1], as does the Stellarium planisphere software. Clackpot ( talk) 18:07, 31 May 2010 (UTC)
The distance listed is way off if you try to calculate it using the parallax equation (distance = 1 / parallax). It should be closer to 430 pc. A quick Google search supported this. I have no idea where the 802 figure comes from, but it's not even close to being correct. — Preceding unsigned comment added by 209.106.183.195 ( talk) 13:37, 3 October 2013 (UTC)
In the table of properties of deneb, what's the "log g" all about? 65.130.253.244 ( talk) 04:37, 15 March 2014 (UTC)
@ Lithopsian what is Earth's log g? hi ( talk) 16:59, 2 May 2015 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Deneb. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{
Sourcecheck}}
).
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— InternetArchiveBot ( Report bug) 23:09, 10 December 2016 (UTC)
The following text has been removed, mostly as it is just speculation. Worse, the source does not mention Deneb and the parallax measure won't apply as the star is brighter than the limit G<3 (less than 3rd magnitude.) Deneb is 1st magnitude.
"The Gaia satellite should provide distance measurements at least two orders of magnitude more precise than Hipparcos and resolve many such questions. The mission did not plan to observe stars brighter than magnitude 5.7, but better than expected performance and special measurement techniques are expected to enable coverage of brighter stars including first magnitude objects such as Deneb."
For this to be added the statement needs a better proof, as nether of the given references by Turon et al (2000) and Prusti (2016) say this at all. GAIA will unable to give Deneb any parallax results as the statement claims.
Note: Deneb is a prototype of ACYG variable stars. It is not that "Deneb is the prototype of the Alpha Cygni type (ACYG)" but it is the brightest example of ACYG's know. Edits changed this context, as did several other changes. Arianewiki1 ( talk) 22:51, 31 March 2019 (UTC)
This section has the following paragraph: "Stars evolving red-wards for the first time are most likely fusing hydrogen in a shell around a helium core that has not yet grown hot enough to start fusion to carbon and oxygen. Convection has begun to carry the products of fusion up to the surface, but these are not visible. Post-red supergiant stars are expected to show those fusion products at the surface due to stronger convection during the red supergiant phase and due to loss of the obscuring outer layers of the star. Deneb is thought to be evolving redwards, although current models do not exactly reproduce the surface elements showing in its spectrum.[24]"
In one sentence, it is asserted that the fusion products brought to the surface by convection can't be seen. In a later sentence, it is said that models can't reproduce the surface elements that are seen in spectra.
This appears to be somewhat contradictory, so I'm wondering if the point can be clarified. Attic Salt ( talk) 13:08, 2 April 2019 (UTC)
This edit [2] that is based on a illogical premise. Again, while Deneb might be a variable star, it is trivial fact about it. Deneb is a bright first-magnitude star in Cygnus. That is what it is known for. My dictionary says "the brightest star in the constellation Cygnus, a yellow supergiant."
This User is similarly arguing this on Rigel and in this thread here. Talk:Rigel#First couple of sentences in lede (It is an example of WP:POINTy behaviour.) Arianewiki1 ( talk) 23:58, 26 April 2019 (UTC)
The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:
Participate in the deletion discussion at the nomination page. — Community Tech bot ( talk) 04:23, 9 February 2020 (UTC)
It is surprising that the distance and other derived stellar parameters for Deneb are not based on the 2007 Hipparcos reanalysis or subsequent journal articles based on this astrometry data. Instead the citation is to a journal article (Schiller and Przybilla 2008) whose distance estimate is based on Humphreys 1978, a now quite old set of estimates of distances to OB associations. There is no good scientific reason cited for this choice. The reference to the distance controversy for the Pleiades seems quite irrelevant to Deneb and indeed many other Wikipedia articles do cite the Hipparcos reanalysis data as the source for stellar distance data.
I recommend that this article use a Deneb distance of 433 parsecs, derived directly from the Hipparcos reanalysis value for Deneb of 2.31 mas — Preceding unsigned comment added by Galaxymap ( talk • contribs) 20:46, 29 January 2020 (UTC)
![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 |
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. Icalanise ( talk) 17:52, 25 July 2011 (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? Alfio 12:14, 21 August 2006 (UTC)
The article states that "Even assuming the lowest estimates of distance and luminosity, Deneb is the brightest and most distant of the first magnitude stars." This is a bit misleading, since "first magnitude stars" ( technically, those between 0.51 and 1.50 apparent magnitude) is a bit obscure and even lowest estimates of its distance place it closer than δ CMa, which is has an apparent magnitude of 1.83. — Aldaron • T/ C 22:45, 15 October 2012 (UTC)
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? 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 [1], as does the Stellarium planisphere software. Clackpot ( talk) 18:07, 31 May 2010 (UTC)
The distance listed is way off if you try to calculate it using the parallax equation (distance = 1 / parallax). It should be closer to 430 pc. A quick Google search supported this. I have no idea where the 802 figure comes from, but it's not even close to being correct. — Preceding unsigned comment added by 209.106.183.195 ( talk) 13:37, 3 October 2013 (UTC)
In the table of properties of deneb, what's the "log g" all about? 65.130.253.244 ( talk) 04:37, 15 March 2014 (UTC)
@ Lithopsian what is Earth's log g? hi ( talk) 16:59, 2 May 2015 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Deneb. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{
Sourcecheck}}
).
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— InternetArchiveBot ( Report bug) 23:09, 10 December 2016 (UTC)
The following text has been removed, mostly as it is just speculation. Worse, the source does not mention Deneb and the parallax measure won't apply as the star is brighter than the limit G<3 (less than 3rd magnitude.) Deneb is 1st magnitude.
"The Gaia satellite should provide distance measurements at least two orders of magnitude more precise than Hipparcos and resolve many such questions. The mission did not plan to observe stars brighter than magnitude 5.7, but better than expected performance and special measurement techniques are expected to enable coverage of brighter stars including first magnitude objects such as Deneb."
For this to be added the statement needs a better proof, as nether of the given references by Turon et al (2000) and Prusti (2016) say this at all. GAIA will unable to give Deneb any parallax results as the statement claims.
Note: Deneb is a prototype of ACYG variable stars. It is not that "Deneb is the prototype of the Alpha Cygni type (ACYG)" but it is the brightest example of ACYG's know. Edits changed this context, as did several other changes. Arianewiki1 ( talk) 22:51, 31 March 2019 (UTC)
This section has the following paragraph: "Stars evolving red-wards for the first time are most likely fusing hydrogen in a shell around a helium core that has not yet grown hot enough to start fusion to carbon and oxygen. Convection has begun to carry the products of fusion up to the surface, but these are not visible. Post-red supergiant stars are expected to show those fusion products at the surface due to stronger convection during the red supergiant phase and due to loss of the obscuring outer layers of the star. Deneb is thought to be evolving redwards, although current models do not exactly reproduce the surface elements showing in its spectrum.[24]"
In one sentence, it is asserted that the fusion products brought to the surface by convection can't be seen. In a later sentence, it is said that models can't reproduce the surface elements that are seen in spectra.
This appears to be somewhat contradictory, so I'm wondering if the point can be clarified. Attic Salt ( talk) 13:08, 2 April 2019 (UTC)
This edit [2] that is based on a illogical premise. Again, while Deneb might be a variable star, it is trivial fact about it. Deneb is a bright first-magnitude star in Cygnus. That is what it is known for. My dictionary says "the brightest star in the constellation Cygnus, a yellow supergiant."
This User is similarly arguing this on Rigel and in this thread here. Talk:Rigel#First couple of sentences in lede (It is an example of WP:POINTy behaviour.) Arianewiki1 ( talk) 23:58, 26 April 2019 (UTC)
The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:
Participate in the deletion discussion at the nomination page. — Community Tech bot ( talk) 04:23, 9 February 2020 (UTC)
It is surprising that the distance and other derived stellar parameters for Deneb are not based on the 2007 Hipparcos reanalysis or subsequent journal articles based on this astrometry data. Instead the citation is to a journal article (Schiller and Przybilla 2008) whose distance estimate is based on Humphreys 1978, a now quite old set of estimates of distances to OB associations. There is no good scientific reason cited for this choice. The reference to the distance controversy for the Pleiades seems quite irrelevant to Deneb and indeed many other Wikipedia articles do cite the Hipparcos reanalysis data as the source for stellar distance data.
I recommend that this article use a Deneb distance of 433 parsecs, derived directly from the Hipparcos reanalysis value for Deneb of 2.31 mas — Preceding unsigned comment added by Galaxymap ( talk • contribs) 20:46, 29 January 2020 (UTC)