Talk:WR 31a

Latest comment: 7 years ago by Arianewiki1 in topic Type Ib/c supernova

WR 31a Recent Edits by Lithopsian

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@Lithopsian: @ScrapIronIV: The recent edits on WR 31a by Lithopsian were not greatly appreciated, being one of the most hostile group of edits I've experienced. Edits should be based on WP:GF, but from your previous unfriendly and uncompromising behaviour on Brightest stars, this current effort could be construed as deliberate provocation.

Wikipedia is supposedly based on consensus, and making edits what the Talk page is for! If you are unprepared to do cooperative editing with other editors, you should probably do something else.

Yet you add [1], saying it is of low-importance, then make the text more confusing and disjointed. What is worst is that you took out five relevant and current references, which connected the HST image and its recent related story, left several sentences uncited and stated opinions not fact. I.e. "It is more commonly referred to as Hen 3-519, as it was known before being listed in the Catalogue of Wolf Rayet stars." According to whom? What catalogue of Wolf-Rayet stars. Hoffliet cataloged both the star and nebula first, hence the title of his 1953 paper "Preliminary Survey of Nebulosities and Associated B-Stars." You do realize Karl G. Henize only saw a B-type star with emission lines in his 1967 catalogue, and this had nothing to do with the later spectral class classifications.

There are also several plainly very obvious mistakes, especially centrally around Hen 3-519 and LBV stars.

1) You now say in the introduction it is a "post-Luminous Blue Variable (LBV)" then under properties say "confirmed LBV." The source actually says; "LBV candidates" WR 31a does not appear on the Luminous blue variable page either. Clearly it is now known as a Wolf-Rayet.
2) He3-519 "On this basis it has been classified as Ofpe/WN9,/..."Then say the same type of spectrum is "WN11", while the textbox now says "WN11h"! You realise the O star designation is the nearest O-type star not WR 31a! "WN11h" is correct. (Do you know what the 'h' means here?)
3) The HST 2016 reference [2] says at least 20 solar masses, but you somehow quote Smith at 45 solar masses. But this source doesn't say this! This mass quoted is the progenitor mass (Meff), being "Adopted effective initial ZAMS mass (not a measurement) based on single-star evolutionary tracks appropriate for the star’s present-day luminosity. For Galactic objects, uncertainty is dominated by the distance and is hard to quantify." As these stars have very significant mass loss, something like 1 Solar mass per 10,000 years. (explaining the nebula existence.)
4) You removed my statement "Mass of the central star is estimated to be at least 20 times that of the Sun, and it will likely become a supernova type II event in the future.", when I gave Ref 7.[3] This is equally confirmed in Luminous blue variable [4], where it says; "The latest models of stellar evolution suggest that some single stars with initial masses around 20 times that of the Sun will explode as LBVs as type II-P, type IIb, or type Ib supernovae,[12]", which is under specified reference Sana, H.; De Mink, S. E.; De Koter, A.; Langer, N.; Evans, C. J.; Gieles, M.; Gosset, E.; Izzard, R. G.; Le Bouquin, J.- B.; Schneider, F. R. N. (2012). "Binary Interaction Dominates the Evolution of Massive Stars". Science. 337 (6093): 444. arXiv:1207.6397. Bibcode:2012Sci...337..444S. doi:10.1126/science.1223344. PMID 22837522. So why remove this??
5) The uncited text under 'Properties' says "The same type of spectrum is also known as WN11, an extension of the traditional nitrogen sequence to cooler temperatures." Who says this? What cooler temperatures? Wolf-Rayet classification are based on the degree and strengths of certain carbon or nitrogen bright emission lines NOT actually temperature - mostly because their photospheres prevent estimations of surface temperature!! This is why "The almost unique nature of WR 31a and its unusual spectrum make determination of its distance and physical properties very uncertain." (but you uncite this quote too!)
Don't you realise, the measurement of the size, expansion rate and the emissions from the nebulosity in the HST, allows calculation of the object's distance. I.e. "Distance is estimated to be about 9,200 parsecs or 30,000 light-years."? THAT IS WHAT TOALA et. al. (2015) are saying!! The at least 20 solar masses that is quoted, is then based on this distance, as based on the expectant stellar absolute magnitude/luminosity.
Worst, your uncited statement "It is close to AG Carinae, a confirmed LBV that has a WN11 spectrum at visual minimum and is calculated to be at a similar distance.", which you paraphrased from Smith, is an estimation, superseded by the HST image and Toala (2015) if their assumptions are correct.
6) What the hell is a "slash star" I.e. Under Properties "On this basis it has been classified as Ofpe/WN9, a slash star." Based on what and what source?

...and these are only the worst ones.

If really you want to 'fix' other's work, actually get you facts straight, cite sources properly, and actually understand the subject at hand.

Justify these statements properly, or they will be removed under Wikipedia adopted policies. Arianewiki1 (talk) 15:05, 11 March 2016 (UTC)Reply

@Arianewiki1: I have never touched this article. Please do not involve me in your disputes with other editors. ScrpIronIV 16:01, 13 March 2016 (UTC)Reply
I'm putting back the improved version. I have given up engaging with Arianwiki1 since that author has been repeatedly abusive to me, making demands, chasing down my edits, and simply being difficult where it would be easier to be helpful. Lithopsian (talk) 12:40, 22 April 2016 (UTC)Reply
You are currently avoiding gaining any consensus in your edits. I have pointed out the flaws in your edits, which you have not even bothered to discuss nor attempted to correct. Your accusations here also avoid WP:GF and this now extends to WP:3RR edit warring. Arianewiki1 (talk) 12:54, 22 April 2016 (UTC)Reply
You are currently (again) avoiding gaining any consensus in your edits. I have pointed out the significant flaws in your edits, which you have not even bothered to discuss nor attempted to correct. I.e. The HST 2016 reference [5], for example, says at least 20 solar masses, but you somehow quote Smith at 45 solar masses. But this source doesn't say this! The 45 solar masses is clearly doubtful. As for "I'm putting back the improved version." Why? especially if it is wrong! Arianewiki1 (talk) 15:53, 1 May 2016 (UTC)Reply
Drivel. Stop making up stuff above your pay grade and just report what the experts say. See WP:SYNTH, WP:OR, WP:TRUTH, and most importantly WP:COMPETENCE. Lithopsian (talk) 13:49, 18 October 2016 (UTC)Reply

Query

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I don't understand the reverting. It looks like the main controversy is over whether it is a LBV or a WR star. It seems that it has been confirmed as a WR star, so that's what the article should say. On the other hand, I'm not sure why a lot of the metadata and templates were removed.

jps (talk) 17:25, 1 May 2016 (UTC)Reply

jps said; "On the other hand, I'm not sure why a lot of the metadata and templates were removed." Good point. I've fixed this with qualifications - but worried about WP:3RR rule.
The full explanation of the events is here [6]. Also this issues are with the statements of the required corrections, which the editor has just mostly ignored. Many of the references in the article claim facts to the article's text, where the reference doesn't say so. The failure IMO is the implications are not fully understood by the editor, so that much of the article looks like personal research rather than an objective analysis. I.e.
1) Most of the LBV edits are irrelevant because they do not directly relate to WR31a itself. I.e. AG Car is a LBV with WN11 spectra, but that has nothing to do with WR31a. The true statement is that "...two WN11 stars: AG Car and He 3-519. The latter had earlier been coined ‘a peculiar WO spectral classification post-LBV, pre-WN star' by Davidson et al. (1993)"
2) WN11 or WN11h in a spectrum has little to do with surface temperature. This is because WN WC classification is based on the line strengths in the spectrum. Surface temperatures cannot be measured because of the activity of the photosphere which is prodigiously expelling its atmosphere into space forming a thick stellar wind . I.e. Read VIII Catalogue of Wolf-Rayet stars (2001) pdf. [7] This says in black and white (pg.136); "A classification system based on such emission lines will therefore not be closely coupled to the stellar parameters of effective temperature and luminosity."
3) WN11 have roughly equal NII and HeII lines or are absent, and will show Balmer lines and He I and display the P Cygni phenomena.
4) I asked the user did he known what the 'h' stood for (no response.) It stands for hydrogen, actually, absent or present.
5) The removal of the statement about Supernova, where as the same WR catalog says "It is important to discover and monitor WR stars,... a tracer of star formation in spiral arms, and a representative of the one but final phase in the evolution of massive stars, to be followed, probably, by a Type Ib / Ic supernova explosion." + Nine sources supporting it!!
Considering that the main Wolf-Rayet doesn't mention anything like this detail, much of this 'improvement' leaves much to be desired, and frankly looks like persona research.
I've fixed it once. Why do it again? Arianewiki1 (talk) 20:56, 1 May 2016 (UTC)Reply
Let's not worry about 3RR for now. Let's just try to get the best article possible. I see you've fixed it once, but I imagine that the other user was confused by the difference in format rather than substance. jps (talk) 22:55, 1 May 2016 (UTC)Reply
jps said; "...but I imagine that the other user was confused by the difference in format rather than substance." On what evidence? For Lithopsian to say; "I have given up engaging with Arianwiki1 since that author has been repeatedly abusive to me, making demands, chasing down my edits, and simply being difficult where it would be easier to be helpful.", suggests no interest in these difference at all, and avoid scrutiny. Talk pages are to sort out differences between editors. On the Talk page. the only statement is what is just said above - and nothing at all of the contention in the article's substance. I've repeatedly asked six separate times on this page to "Discuss on talk page" or get "consensus." Worst Lithopsian had one whole month to engage with the article's issues. He did nothing. Seemingly unable or unwilling to engage in getting consensus, I reverted these edits to the previous stable version. (This wasn't just a simple stub!) The only explanation left is that these edits are almost certainly 'personal' in their motivation as in saying things like being "My final word" suggest unwillingness towards any cooperative editing. WP:TALKDONTREVERT in this case is towards evidence of WP:DE by WP:RUNAWAY.
Regardless, I have now put a Talkback towards Lithopsian, and hope to get an decent explanation for all of this. Arianewiki1 (talk) 00:36, 2 May 2016 (UTC)Reply
I should also have noted that further attempts in solving this problem appears User:Lithopsian#Edit Warring, but was further rebuffed and faced another WP:PA with false statements. Thanks. Arianewiki1 (talk) 01:04, 2 May 2016 (UTC)Reply
Lithopsian. I'd like to suggest you read and be aware of WP:DISCFAIL, especially section on WP:DISCFAIL#The process before going any further down this current path.

Thanks. Arianewiki1 (talk) 00:46, 2 May 2016 (UTC)Reply

I have only the edit summary to go by! Not a lot of information, I acknowledge. But let's try to see if we can't get the infobox and categories back in, shall we? jps (talk) 01:38, 2 May 2016 (UTC)Reply

WR 31a Lithopsian's 1st October Edit

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@Lithopsian: @I9Q79oL78KiL0QTFHgyc: I concur with much these series of edits, which reflect the nature of WR31a. There is still need for discussion on Talk pages here, especially with contentious material.

Two Significant Reverts

  • I have again modified the distance to 9200 parsec not older and the incorrect 8,000, which is based on recent measurements and assumptions from the HST image. This value is decided by the diameter of the nebula itself and the expansion rate - basic astrophysics, actually. (Toala et al. (2015) actually say this and describe the procedure!!)
  • As this star has no white dwarf companion of note, destruction is a Type II, and cannot be a Type I. Therefore, saying Type II is correct than just "supernova." (If it did, it could be Type II for the primary & later Type I for a theoretically existing white dwarf.)

Discuss here (again) before reverting, please. Else it is disruptive editing, which is by repeated changes sanctionable. Thanks.Arianewiki1 (talk) 06:57, 1 October 2016 (UTC)Reply

Another revert was again not discussed on Talk page, which is again evidence of disruptive editing. Please do so. Arianewiki1 (talk) 15:16, 10 October 2016 (UTC)Reply
Fifth revert was again not discussed on Talk page, which is again evidence of disruptive editing. Please do so.Arianewiki1 (talk) 00:59, 13 October 2016 (UTC)Reply
Quote: "For the first time ever, scientists have direct confirmation that a Wolf-Rayet star—sitting 360 million light years away in the Bootes constellation—died in a violent explosion known as a Type IIb supernova." (being SN 2013cu) [8] What else can be said? Arianewiki1 (talk) 01:10, 13 October 2016 (UTC)Reply
Reverted last edits again. No consensus with these edits. Arianewiki1 (talk) 22:00, 15 October 2016 (UTC)Reply
Paper entitled "Nonconservative Mass Transfer in Massive Binaries and the Formation of Wolf-Rayet+O Binaries" 14th October 2016 [9] Quote: "The evolution of massive binaries plays a vital role in various aspects of astrophysics, and their evolutionary products are related to many interesting phenomena, e.g. type Ib/c supernovae" As the WR star is single, the only outcome is supernova Type II. Hence the edits and necessary reverts. Evidence enough. Arianewiki1 (talk) 23:51, 17 October 2016 (UTC)Reply

Dubious tags

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There are three dubious tags. I'm not entirely sure what they are for but here is further guidance on where to confirm the claims in the given references:

  • Variable type cLBV - Naze et al 2012, table 1, section B (candidate LBVs), 8th entry and Smith & Tombleson 2014, table 1, third entry, candidates parenthesised
  • Luminosity 1,820,000 - Naze et al 2012, table 1, section B (candidate LBVs), 8th entry, log luminosity given as 6.26 and van Genedern 2001, Vizie table1 gives log luminosity as 6.26
  • Temperature 30,200 - Naze et al 2012, table 1, section B (candidate LBVs), 8th entry, log temperature given as 4.48 and van Genedern 2001, Vizie table1 gives log temperature as 4.48
BS. These are based on distance of the star which has changed, and is therefore different. Hence dubious.Arianewiki1 (talk) 09:13, 28 October 2016 (UTC)Reply
You're kidding, right? You know better than peer-reviewed articles published in the 21st century? Lithopsian (talk) 09:20, 28 October 2016 (UTC)Reply

Type Ib/c supernova

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A type Ib/c supernova is a stripped envelope supernova. It occurs when the core of a massive star collapses and there is no hydrogen (or helium for a type Ic) left in the atmosphere. This has nothing to do with a white dwarf. Wolf-Rayet stars produce type Ib/c supernovae, whether they are single or in binary systems. The article is incorrect to state that WR31a will produce a type II supernova. Doubly incorrect without a citation. Lithopsian (talk) 11:45, 31 October 2016 (UTC)Reply

@Lithopsian: Even more BS. The explanation of Ib or Ic supernovae is twofold - either as binary systems or single stars, whose progenitor has mass loss is either by accretion or wind. There is still no recognised principle theory for the cause of these events, which is open to some debate. The initial paper with this is "Type Ib/c Supernovae and their Relation to Binary Stars" [10] (1995) says this directly. Worse, even the recent papers still show doubts (I.e. 10 January 2017, yesterday when I wrote this.) I.e. Paper "Type Ib and IIb supernova progenitors in interacting binary systems." [11].
It even says in black and white...
"Type IIb supernovae (SNe) belong to the class of hydrogen-poor core-collapse SNe. They appear as a Type II SN initially but gradually turn into a Type Ib SN days to weeks after the explosion. This property can be best explained by a progenitor star having a small amount of hydrogen (MH,env ≈ 0.01 − 1.0 M⊙) in the envelope."
On Ib/c supernova, the same author(s) say in black and white (2012) (first line!!) [12]:
"The progenitors of many Type II supernovae have been observationally identified but the search for Type Ibc supernova (SN Ibc) progenitors has thus far been unsuccessful, despite the expectation that they are luminous Wolf-Rayet (WR) stars."
They even conclude (pg.5)
"Our study has shown that the masses of SNe Ibc progenitor stars are not linearly correlated with their optical brightness and that the evolution of the surface properties of massive helium stars during their final evolutionary stages should be carefully investigated. The non-detection of a SN Ibc progenitor even with a good detection limit does not necessarily imply that its progenitor is a relatively low-mass helium star, and vice versa. This should be properly taken into account in future observational efforts to directly identify SNe Ibc progenitors."
This is still true today..
Still, WR31a problems are still openly debatable.
  • It also has not be shown to be a binary.
  • Its true distance is doubtful, and results already contradict each other, hence too, the luminosity/ absolute magnitude is doubtful.
  • Its current mass is doubtful as is the expectant mass when it goes supernova.
  • The belief is that the cause of the demise is still questionable (as to explaining the event of hypernovae.)
The central problem is being unable to recognise the difference between fact and theoretical explanations of these events.
So please when you say things like: "Wolf-Rayet stars produce type Ib/c supernovae, whether they are single or in binary systems."
Get your facts right. The jury on the outcome of these stars still remains uncertain. I.e. It is still theoretical NOT fact.
It is clear you are an intelligent editor, but is also clear you lack the wisdom in looking at the wider holistic view of the topic. (The issue of these incorrect statements made by Lithopsian is also with the Wolf-Rayet page, too.) Arianewiki1 (talk) 01:10, 11 January 2017 (UTC)Reply