Talk:VY Canis Majoris

Edit request from Heliumsingh5000, 15 July 2011

In the following given data in the article

" Size

University of Minnesota professor Roberta M. Humphreys estimates the radius of VY CMa at 1,800 to 2,100 solar radii.[9] To illustrate, if Earth's Sun were replaced by VY Canis Majoris, its radius might extend beyond the orbit of Saturn (about 9 AU). Assuming the upper size limit of 2100 solar radii, light would take more than 2.7 hours to travel around the star's circumference, compared to 14.5 seconds for the Sun. It would take 7×1015 Earths to fill the volume of VY Canis Majoris.

"

It should be noted that the time required for the light to travel the circumference of the star is around 8 hours as opposed to the given 2.7 hours

we can calculate according to the given radius of the star

Circumfrence = 2*pi*r = 2 * 3.1428527 * (2100*695,500) KM = 9,180,600,000 KM

Speed of light = 300000 KM/Sec

therefore time taken for a complete circumference =

9,180,600,000/300000 Sec = 30 602 sec = 8.50055556 hours

Heliumsingh5000 (talk) 11:40, 15 July 2011 (UTC)

Article is no longer protected so you may edit it yourself now. Jnorton7558 (talk) 00:03, 17 July 2011 (UTC)

I changed it to 8.5 Bhny (talk) 00:10, 30 September 2011 (UTC)

Radius (again)

Almost a year to the date since the last discussion, here we are again. This time, the question seems to be about Massey et al (2006) and its value of 650 R_☉ vs the current starbox values of 1,420 R_☉ and 2,063 R_☉. Discuss. Lithopsian (talk) 17:38, 4 November 2021 (UTC)

While It is my personal opinion that I think the 1,420 solar radii estimate is the most reliable out of the 3 estimates, it also appears to be the most agreed upon, so I would leave the page as is. -The Space Enthusiast (talk) 23:27, 4 November 2021 (UTC)

I personally see no reason in adding the 600 R_☉ estimate, the 1,420 R_☉ estimate is far superior in every way. Currently the older value (600 R_☉) is purely of historical interest and shouldn't be considered a reliable estimate for VY CMa anymore. nussun (talk) 18:40, 6 November 2021 (UTC)

I agree. The 1,420 solar radii estimate is also the one that fits with VY Canis Majoris’ observations the most, according to a response paper by Roberta M. Humphrey.- The Space Enthusiast (talk) 00:08, 7 November 2021 (UTC)

Which paper? nussun (talk) 07:19, 8 November 2021 (UTC)

This one:https://arxiv.org/pdf/astro-ph/0610433.pdf — Preceding unsigned comment added by The Space Enthusiast (talk • contribs) 08:13, 8 November 2021 (UTC)

That's older than the paper which states 1,420 Rsol. You must have the wrong one. nussun (talk) 13:00, 9 November 2021 (UTC)

Yes, but I think it illustrates why the 600 solar radii estimate is too low for VY CMa. I will post more things later.--The Space Enthusiast (talk) 22:59, 9 November 2021 (UTC)

What radius do we use...

Unfortunately, we are here again. *sighs*... What radius do we use? I would use the 1,420 solar radii estimate but others support the 600 solar radii estimate. What do we use?--The Space Enthusiast (talk) 09:38, 12 December 2021 (UTC)

Which others? Lithopsian (talk) 20:49, 12 December 2021 (UTC)

I am sorry if my statement was confusing, but I was referring to one person; User:SpaceImplorerExplorerImplorer. I don’t want to insult him though, just clarifying what person was supporting the 600 solar radii estimate for VYCMa. His statement is pretty legitimate(At least in my opinion). He said that as we know that VY Canis Majoris is a variable star, 600 solar radii isn’t out of the question, and that is why we have the list of largest stars as we know it today with VY Canis Majoris being 600 solar radii in estimate. —The Space Enthusiast (talk) 12:55, 13 December 2021 (UTC)

Clear enough who that is. They aren't a reliable source by WP criteria, so I wouldn't worry about it. Lithopsian (talk) 21:28, 13 December 2021 (UTC)

Just to say that source that says 545-955 R_☉ is not unreliable, it is also not because it is old and again the paper says that it is certainly not in hydrostatic equilibrium. SpaceImplorerExplorerImplorer (talk) 18:39, 14 December 2021 (UTC) ...and the radius is much farther from the limit than the 1,420 R_☉. So I would say that the 605 R_☉ is more reliable.

WP has a thing called WP:OR. The paper you place so much faith in made the claim that VY CMa was a relatively normal red supergiant, with a typical luminosity and radius. This was in contrast to even older estimates that were much larger, 2,000 - 3,000 R_☉ or so. The claims of not being in a feasible location for hydrostatic equilibrium applied to the older estimates, not to the current ones. The reduction of the luminosity to 60,000 L_☉ has since been rejected by every publication on the subject. Those newer peer-reviewed papers are the ones we must follow as demonstrating the current consensus, albeit still with some variation. Massey et al, and the older papers for that matter, can be mentioned in a historical context. Lithopsian (talk) 21:17, 14 December 2021 (UTC)

Additionally, I have seen papers that have said that Massey et al' s properties don't take into account the well-known extremities of VY Canis Majoris. - The Space Enthusiast (talk) 07:12, 30 April 2022 (UTC)

Quote them or link them here, otherwise it is just hearsay. If we have reliable sources, we can include them in the article to either confirm a consensus viewpoint or show areas of doubt. Lithopsian (talk) 14:19, 1 May 2022 (UTC)

Semi-protected edit request on 4 January 2022

Change: The star have produced a large, probable convection-driven, mass-loss events dated to 70, 120, 200 and 250 years before 2020. The clump shed by star in 1985–1995 is the source of hydroxyl maser emission.[51]

To: The star has produced large, probable convection-driven, mass-loss events dated to 70, 120, 200 and 250 years before 2020. The clump shed by the star in 1985–1995 is the source of hydroxyl maser emission.[51] Olesweerlow (talk) 13:22, 4 January 2022 (UTC)

OS Olesweerlow (talk) 13:23, 4 January 2022 (UTC)

 Done ScottishFinnishRadish (talk) 13:28, 4 January 2022 (UTC)

Semi-protected edit request, June 14 2022: Improve image caption

Don't know why this article is protected, (and it isn't noted, but I can't see the edit button) but could someone please improve the image caption for the "combined optical.." image in the "Distance" section? Current, and proposed:

Change: "Combined optical and infrared image of VY CMa. The bright star at the upper right is τ Canis Majoris."

to: "Combined optical and infrared image of VY CMa (image centre). The bright red star just right of centre is δ Canis Majoris (Wezen), the bright star at the upper right is τ Canis Majoris."

This will greatly improve the clarity of the image, as VY is not bright enough to be obviously the subject of the image. 2001:56A:F0E9:9B00:A500:3B4E:4CA7:B39E (talk) 16:19, 15 June 2022 (UTC)JustSomeWikiReader

It might improve the clarity of the image, but it would be wrong. The bright red star just right of centre is not δ CMa, it is MZ CMa. Lithopsian (talk) 16:41, 15 June 2022 (UTC)