Talk:VV Cephei

message: W Cephei is by far I know the bigest star in the Unerverse there might be bigger stars that havnt been discovred  —Preceding unsigned comment added by 81.156.32.168 (talk) 13:47, 22 February 2008 (UTC)
replies: text: How big of a tatonka size telescope do you need for this?  —Preceding unsigned comment added by Kingkong77 (talk • contribs) 14:30, 7 October 2008 (UTC)
thread_title:  VV Cephei 

message: Doesn't seem to be right
that puts me right outside of hercules, not cepheus--Vennificus (talk) 01:24, 15 March 2010 (UTC)
replies: text: The location checks out correct according to my printed Norton's Star Atlas: it lies between iota and alhpa Cepheus. I have added this location map. -84user (talk) 19:17, 16 March 2010 (UTC)
thread_title: Location

message: Is this "Vee Vee" Cephei, or "Five Five", or something else?  Or is it something in Greek that hadn't occurred to me? :o)  - 94.194.113.136 (talk) 16:25, 16 May 2012 (UTC)
replies: text: It's vee vee, it's from the Bayer designation, which initially used Latin letters after the 24 Greek ones had expired, but this only survived mainly in designations for variable stars, which always begin with a letter from R to Z. - filelakeshoe 20:03, 16 May 2012 (UTC)
thread_title:  Pronunciation 

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thread_title:  Image submitted for deletion 

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thread_title:  A Commons file used on this page has been nominated for deletion 

message: According to Nussun05,  Messineo & Brown 2019 listed VV Cephei A as  based on the luminosity and temperature though I can't find luminosity and temperature of the listed stars in any tables or pages in the given citation. Should we use it? 2A01:E0A:47A:F100:D025:C6CB:707E:5CDA (talk) 07:44, 23 May 2020 (UTC)
replies: text: The data is online at VizieR.  It assumes the Gaia DR2 distance of , which is barely a third of the consensus value of .  Hence a much lower luminosity of  and the smaller radius.  The radius value should be treated with caution since it is based on treating the whole system as a single star.  Although the parallax has quite a large formal error, as well as no corrections for being a binary, it is consistent with the Hipparcos parallax which has been ignored or dismissed by most authors until now.  Surely at least worth a mention in the text even if it isn't yet the accepted value.  Lithopsian (talk) 13:09, 23 May 2020 (UTC)
thread_title:  New estimate for VV Cephei A 

message: Recent research contradicts the beginning of this article, where it states that mass transfer occurs via Roche lobe overflow. Whmbkx (talk) 01:44, 21 November 2020 (UTC)
replies: text: Could you please provide a link to said research? Primefac (talk) 12:43, 21 November 2020 (UTC)
thread_title: Contradiction

message: Should this value really be used in the starbox? It is based on Gaia Data Release 2 data, and has a massive significance of astrometric excess noise. Pollman, E.; et al. (2018) is a study solely based on VV Cephei itself. It should be used over . Faren29 (talk) 22:54, 25 December 2020 (UTC)
replies: text: Parallaxes from Hipparcos, DR2, and EDR3, are all similar, around a milli-arcsecond.  High astrometric noise indicates a possible issue, not that the value is wrong.  High astrometric noise is expected for a binary, non-stellar object such as VV Cep, and the parallax may still have some merit.  The "classical" distance from other methods is around 1.5 kpc, but also highly uncertain.  Pollman et al. adds nothing to the equation, it is just repeating earlier results (eg. Bauer et al., 2008) and not deriving new ones.  "~1,000" should probably be dropped from the starbox and replaced with something specific such as  from Bauer et al.  Lithopsian (talk) 16:05, 27 December 2020 (UTC)
replies: text:  from Hagen Bauer, Wendy; et al. (2008) seems trustworthy, but Hopkins, Jeffrey L.; et al. (2015) also references many radii for VV Cephei A. This includes: , which is most likely the same case you described for Pollman, Ernst; et al (2019), , from Bennett, Philip D. (2007), , from Wright, K. O. (1977) and Hack, M.; et al. (1992), and , from Hutchings, J. B. and Wright, K. O. (1971). Aside from the trusted value of , are there any values that could potentially be used in the starbox in Hopkins, Jeffrey L.; et al. (2015)? Faren29 (talk) 19:10, 27 December 2020 (UTC)
replies: text: There is a short section about the distance.  You could expand that and mention the various estimates and the inconsistencies between the parallaxes (600-1000 pc) and distances from methods like the orbit and eclipses (1,500+ pc).  I wouldn't put anything from last century in the starbox.  Then decide which of the radius values comes out as most reliable for the starbox.  Lithopsian (talk) 14:36, 28 December 2020 (UTC)
thread_title:  How reliable is Stassun, K. G.; et al. (2019)? 

message: The values for parallax and distance in the starbox are mutually exclusive. The given parallax of 1.33±0.20 mas corresponds to between 654 and 885 pc, approximately half the stated 1500 pc.
The reference for the parallax (Van Leeuwen, 2007) is a paper which applies new methodology for processing the Hipparcos to improve its overall accuracy. It deals with the data set as a whole; the only places where it refers to the parallax of specific stars (for purpose of illustration) are in Table 1 on page 7 (stars HIP 70 and HIP 71) and Table 2 on page 10 (ten stars, 5 with names). None of the mentioned stars appear to be VV Cephei.
Please change
{{Starbox astrometry
  | parallax=1.33
  | p_error=0.20
  | parallax_footnote=
to
{{Starbox astrometry
  | parallax=1.33
  | p_error=0.20
  | parallax_footnote=
98.110.77.253 (talk) 02:14, 26 June 2021 (UTC)
replies: text: , and thank you for the good catch! We won't change the figures just yet; however, we will continue to dig. P.I. Ellsworth  ed. put'r there 15:31, 30 June 2021 (UTC)
thread_title:  Inconsistency in starbox parallax and distance 

message: Where can I find a luminosity for VV Cephei? The current luminosity is probably unreliable because it uses a noisy distance from Gaia. No other values ​​were found, and this is already making me very angry. InTheAstronomy32 (talk) 16:06, 19 May 2024 (UTC)
replies: text: Luminosity here. InTheAstronomy32 (talk) 16:44, 19 May 2024 (UTC)
thread_title:  Luminosity 

message: See User_talk:SpaceImplorerExplorerImplorer#List_of_largest_known_stars_2 for the start of a discussion concerning the calculation of stellar radii from an angular diameter and distance in two unrelated sources.  Lithopsian (talk) 17:34, 20 May 2024 (UTC)
replies: text: Although I think the calculation of radii as described violates WP:SYNTHESIS and so shouldn't generally be used in the starbox, I feel we can stretch things slightly in some cases.  One case might be where there is no sensible published radius that could be used in the starbox.  A calculated radius, suitably caveated, might be better than nothing.  Also, in the body of the article, if such a calculated radius provides useful context to a discussion of the properties, then it could be mentioned and described.  Maybe, if the powers-that-be don't pile in and say it is just never acceptable.  Lithopsian (talk) 17:37, 20 May 2024 (UTC)
replies: text: I believe that we should use common sense here. Calculating a radius by two sources violates only the letter, not the spirit, of the WP:No original research policy, it was further explained in the User talk:SpaceImplorerExplorerImplorer. I think that the radius of  could be used here, despite being calculated angular diameter and distance of different sources. Both the angular diameter and distance are recent and reliable, then the radius should be reliable too. It can be calculated using the  template or the equation R=AD×D.(R = Radius in AU, AD = radius in milliarcseconds, D = distance in parsecs.) Later only divide by 107.5 to find radius in . The another radius of  uses an effective temperature of 3,463 K which is a bit smaller than the typical temperature of a M2-type red supergiant (3660 K), and both are from big catalogs. InTheAstronomy32 (talk) 22:47, 20 May 2024 (UTC)

text: I added back the  value because it is reliable, so it will be not necessary to insert the other radius. InTheAstronomy32 (talk) 19:08, 21 May 2024 (UTC)
thread_title:  [[WP:SYNTHESIS]]