Talk:Virgo Supercluster

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Formation and evolution[edit]

Is a section on Formation and evolution required? See the equivalent entry under Galaxy. This could be included within the Structure section. Presumably the process of development of the disc structure corresponds to the formation of structures at other orders of magnitude - such as disc galaxies and protoplanetary discs --Tediouspedant (talk) 19:44, 6 February 2010 (UTC)[reply]

It would be useful to mention what's known about whether the Virgo supercluster is gravitationally bound. According to the article on the encompassing Laniakea supercluster, Laniakea is not: "Follow-up studies suggest that Laniakea is not gravitationally bound; it will disperse rather than continue to maintain itself as an overdensity relative to surrounding areas." Jess_Riedel (talk) 19:48, 8 November 2018 (UTC)[reply]

Apparent size criterion[edit]

What is considered "large" apparent size? Ardric47 02:17, 20 March 2006 (UTC)[reply]

There's some arbitrary cut-off in terms of angular size: 100 arcseconds. I modelled our list after the one in http://www.atlasoftheuniverse.com/galaclus.html, which also uses this cut-off. It keeps the listing from including heavy but very distant clusters that have been relatively poorly observed. -- Xerxes 01:35, 22 March 2006 (UTC)[reply]

Great attractor[edit]

"The local (Coma-Virgo), Perseus-Piscus, Hydra-Centaurus, Orphiuchus, Vela, and a number of other superclusters are observed to move towards the Great Attractor as speeds of greater than 600,000 km per second," Isn't this about 3 times the speed of light?

It's twice the speed of light. Although it's possible for different parts of the universe to be moving away from each other at faster-than-light speeds (by some definitions) due to the expansion of space, I'm suspicious about that happening so close to us. Ardric47 00:17, 22 March 2006 (UTC)[reply]
You don't want to know. Or maybe you do. This might possibly be harnessed somehow for future spaceships. This is better than an Scramjet!--File:Nuvola apps kcmmemory.pngMac Lover Talk 17:15, 10 August 2006 (UTC)[reply]

Group/cluster list[edit]

The group/cluster member list is a mess. Moreover, this list gets really messy when considering the difficulty in identifying whether galaxies are parts of groups (see the Sombrero Galaxy under "Environment") and the difficulty in distinguishing whether galaxies are subdivided into small groups or combined together into large groups (see my revisions to the M101 Group article and the section labelled "Nearby groups"). This section could be misleading or confusing, and its accuracy will always be questionable, so I am removing the section. GeorgeJBendo 21:21, 28 October 2006 (UTC)

=== Galaxy clouds of the Virgo Supercluster ===

  • Virgo cluster (disk component)
  • Canes Venaciti Cloud (disk component)
  • Virgo II Cloud (disk component)
  • Leo II Cloud (halo component)
  • Virgo III Cloud (halo component)
  • Crater Cloud (halo component)
  • Leo I Cloud (halo component)
  • Leo Minor Cloud (halo component)
  • Draco Cloud (halo component)
  • Antilia Cloud (halo component)
  • NGC 5643 Cloud (halo component)

=== Groups and Clusters of the Virgo Supercluster === Sorted by the number of galaxies they contain with large apparent size:

I think there should be a Members of the Virgo Supercluster article with that list, fleshed out, with notes on why some may or may not be members of the LSC. 70.51.9.132 (talk) 11:37, 24 July 2008 (UTC)[reply]

Image[edit]

There were complaints that Image:Local_supercluster.jpg (the image on the right) was unreadable because it used km, so I made one using light years instead: Image:Local_supercluster-ly.jpg. Hairy Dude 01:04, 7 July 2007 (UTC)[reply]

Do you have references for all of the distance measurements in that figure? For that matter, are those terms for various clusters of galaxies actually in use (i.e. have those terms been used in a scientific journal article published in the past 10 years)? If the answer to either of these questions is no, then maybe the picture should not be used. Dr. Submillimeter 18:30, 7 July 2007 (UTC)[reply]
The orgiginal image created by nasa had distance measurements in it in km. Performing a simple unit conversion is allowed. McKay 16:25, 10 July 2007 (UTC)[reply]
A NASA public outreach website may not be the best source of information for this data. I would contend, for example, that some of these designations are not in use. For example, a search for "Draco Group" in professional astronomy journals with the ADS Abstract Service turns up no articles that use the term. I would also like to see references from journal articles for the distances. The distance to Messier 81 and Messier 82 given by [1], which are part of the M81 Group, is 11.5-11.8 Mly, not 11 Mly as shown in this figure. Similarly, the distance to Messier 51 in the M51 Group is given by [2] is 23 Mly, not the 31 Mly shown in this figure. I sincerely recommend deleting it, as it is inaccurate. Dr. Submillimeter 17:04, 10 July 2007 (UTC)[reply]

expand[edit]

A list of (some) members should be included, and the major divisions of the LSC... (halo, disc, etc)... there's this Leo Spur and Local Sheet... and is the Local Void part of the LSC, or next to it? 70.55.203.50 (talk) 09:33, 6 August 2008 (UTC)[reply]

Name[edit]

I'd like to propose that we rename this page 'Local Supercluster' instead of 'Virgo Supercluster.' Most of the literature uses this name, I believe in part to distinguish this structure from the 'Virgo cluster,' it's main constituent. 'Local Supercluster' has the advantage of being completely unambiguous, standing by analogy with the 'Local Group.' Vegasbri (talk) 18:32, 9 December 2008 (UTC)[reply]

Gsearch Local Supercluster 459000 ghits
Gsearch Virgo Supercluster 112000 ghits
GScholar Local Supercluster 250 ghits
GScholar Virgo Supercluster 31 ghits
GBooks Local Supercluster 287 ghits
GBooks Virgo Supercluster 52 ghits
76.66.195.159 (talk) 02:45, 12 December 2008 (UTC)[reply]
I agree with the proposed move.—RJH (talk) 21:08, 31 December 2008 (UTC)[reply]
  • I think Copernicus would disagree. I personally prefer to avoid labeling anything as "Local" in astronomy, despite the common practice. Also, the usage is extremely ambiguous, since any galaxy cluster can have a local supercluster (and not all languages use capitalization like English to distinguish the difference in translation). I say to keep it as "Virgo Supercluster." Nicole Sharp (talk) 21:38, 9 September 2016 (UTC)[reply]

Old version of article[edit]

[[Image:Local_supercluster-ly.jpg|right|299px|thumb|The Virgo Supercluster]]
The '''Virgo Supercluster''' or '''Local Supercluster''' is the [[galaxy|galactic]] [[supercluster]] that contains the [[Local Group]], the latter containing, in its turn, the [[Milky Way]] and [[Andromeda Galaxy|Andromeda]] galaxies.

===Disk and halo===
The Supercluster consists of two components: disk component and halo component. The flattened disk component has a pancake-like shape, and contains 60% of the Virgo Supercluster's luminous galaxies. The halo component consists of many elongated objects, and contains the remaining 40% of the Virgo Supercluster's luminous galaxies. 

===Diameter===
The diameter of the Supercluster is about 200 million [[light year]]s; it contains about 100 [[groups and clusters of galaxies]] and is dominated by the [[Virgo cluster]] near its center. Our Local Group is located near the edge and is being drawn inward toward the Virgo cluster<ref>This is due to the so-called [[Virgo-centric flow]] towards the center of the supercluster. For details, see [http://www.seds.org/messier/more/virgo.html]</ref>. It is still unclear if at some time in the far future, the Local Group and other galactic clusters will be "eaten" by the very massive [[Messier_87|Virgo A Galaxy]]<ref>See ''The Virgo Cluster and the Local Group of Galaxies'' at [http://www.seds.org/messier/more/vir_loc.html]</ref>.

===Mass===
By tracking its gravitational effect on the movement of galaxies, one can estimate that the total mass of the Virgo Supercluster is about 10<sup>15</sup> [[solar mass]]es (2 &times; 10<sup>46</sup> [[kilogram|kg]]; see [[Orders of magnitude (mass)]]). As its luminosity is far too small for this number of stars, it is thought that a large part of its mass is [[dark matter]].

The entire Virgo Supercluster is being pulled toward a gravitational anomaly known as the [[Great Attractor]], which lies near the [[Norma cluster]].

===Divisions===
The Virgo Supercluster is subdivided into groups of clusters called [[galaxy cloud]]s. Three clouds are on the disk component: [[Virgo cluster]], [[M94 Group|Canes Venatici Cloud]] and [[Virgo II Cloud]].  The halo consists of many elongated clouds pointing toward the Virgo Cluster.

===References===
{{reflist}}
* Brent Tully: ''The Local Supercluster'', Astrophys. J., vol. 257, pp. 389-422 (1982)
* Oscar Monchito: ''Superclusters and Other Stuff'', Colton, vol. 12, pp. 124-118 (1992)

===Further reading===
* ASTRON. SOC. OF INDIA. BULLETIN V. 9, P. 1, 1981 ; [http://adsabs.harvard.edu/full/1981BASI....9....1D The Local Supercluster of Galaxies] ; [[Gerard de Vaucouleurs|de Vaucouleurs, G.]] ; 1981BASI....9....1D 

===External links===
* [http://www.atlasoftheuniverse.com/virgo.html The Virgo Supercluster] from ''An Atlas of the Universe''

=== See also ===
*[[Large-scale structure of the cosmos]]
*[[Extragalactic astronomy]]

{{Milky Way}}
{{Earth's location}}

[[Category:Virgo Supercluster]]
[[Category:Galaxy superclusters]]

Here's the pre-rewrite version of the article (w/o the clickable maps) 76.66.195.159 (talk) 02:35, 12 December 2008 (UTC)[reply]

Too many maps[edit]

There's an overabundance of computer-generated maps. Should there be a least one image that is taken by a telescope in this article?--128.119.51.64 (talk) 01:48, 15 February 2011 (UTC)[reply]

mass contradiction[edit]

I was curious to find what percentage of the mass of Virgo Supercluster is within the Virgo Cluster. It says that the Virgo Supercluster has mass of 10^15 solar masses, and on the article of Virgo Cluster, it says it has mass of 1.2 time 10^15 solar masses. This is absurd, the Virgo Cluster is a part of Virgo Supercluster, and yet Virgo Cluster is heavier. Can someone fix the article, and add information about mass distributions? Is the mass distribution predicted to be the same as luminousity distributions discussed in the article? — Preceding unsigned comment added by Nnnu (talk • contribs) 11:53, 6 April 2011 (UTC)[reply]

It looks to me like Virgo Supercluster currently interprets the current source for the mass of the Virgo Supercluster incorrectly. Right now Virgo Supercluster currently says the mass is 10^15 solar masses, but the source actually says the value is different, at 1 x 10^15 * h^(-1) solar masses. What is h? I'm not sure, but Parsec#Megaparsecs_and_gigaparsecs gives one plausible interpretation. Combining that interpretation with the numeric values in Hubble constant, it seems h is around 0.67 or 0.72. If so, the mass of the Virgo Supercluster would be around 1.3-1.5 x 10^15 solar masses. Can someone with an astronomy background say if this is the proper interpretation of h? Mynameisnoted (talk) 07:37, 4 November 2011 (UTC)[reply]
  • I noticed this contradiction as well. This article states that the combined mass of the Virgo Cluster plus the Local Group is less than that of the mass for just the Virgo Cluster alone. The article cited above states that h is the Hubble constant (H) in units of 100 km/s/Mpc, or h = H/(100 km/s/Mpc) (so that the h used is dimensionless, unlike H). The numerical value of the Hubble constant with the smallest amount of error given on Wikipedia is 67.6 km/s/Mpc, providing the h as used in the cited article a dimensionless value of 0.676, and the mass of the Virgo Supercluster as 0.676−1 × 1015 m☉ = 1.48 × 1015 m☉ (meaning that the Local Group contains only 19% of the mass of the Local Supercluster). Nicole Sharp (talk) 18:17, 9 September 2016 (UTC)[reply]
    • Technically: ~1.48 × 1015 m☉ ± 1015 m☉ (or between 500 trillion and 2 quintillion solar masses). Nicole Sharp (talk) 18:34, 9 September 2016 (UTC)[reply]

Name, again[edit]

There's an article from the Eurekalert site today that reports the designation of a new name for the local supercluster; "Laniakea". If true, then perhaps this article will have to be renamed again. Tmangray (talk) 18:37, 3 September 2014 (UTC)[reply]

No, that is a different structure. Laniakea is a combination of Virgo SCl and Hydra-Centaurus SCl, so it is not the same thing. Virgo SCl is a lobe in the new structure, so should remain where it is. The problem is what to do with the redirect Local Supercluster, since all research until now is about this Virgo SCl, and not the new structure "Laniakea". I've opened a discussion at WT:ASTRO. -- 65.94.169.222 (talk) 12:07, 4 September 2014 (UTC)[reply]

"Local supercluster"?[edit]

Isn't that the Virgo Supercluster? That's still a thing, right? Serendipodous 08:20, 30 March 2015 (UTC)[reply]

"List of galaxy groups in the Virgo Supercluster"[edit]

...could potentially make for a (somewhat) interesting list article. Or perhaps just a NavBox? Praemonitus (talk) 17:29, 23 February 2016 (UTC)[reply]

Binding mass is not total mass[edit]

This article, like Laniakea Supercluster, mixes up binding mass and total mass in the infobox. The binding mass given here, ~1.48 × 1015 solar masses, is the total mass of the cluster, but it is not its binding mass, which is of the order of 1029 solar masses. See Caelum Supercluster for an example of an article that gets it right. Renerpho (talk) 15:27, 26 February 2019 (UTC)[reply]

Why is the binding mass so large? Wouldn't it be a tiny fraction of the total mass? I would've thought gravitational binding mass would be defined relative to infinity. Patallurgist (talk) 23:39, 28 September 2020 (UTC)[reply]
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