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Article requests : Current sites of star formation (possibly Gould Belt, Taurus, Ophiuchus, Orion, etc); frequency/duration of star formation (possibly Star formation efficiency). The free falling picture discussed should be suplemented by the standard model (subcritical cores collapsing after ambipolar diffusion makes them supercritcal) and supersonic turbulent model. Discussing initial mass functions and star formation rate, the effect of the magnetic field and turbulence are probably the central issues in star formation, but they aren't even mentioned in the article.
Star formation and Star Formation currently point to different articles. They should be merged or disambiguated in some way. -- BenRG 09:40, 7 Oct 2003 (UTC)
Ok. Now both point here. --AstroNomer 23:32, Oct 7, 2003 (UTC)
Why do planets form if gravitational collapse is insufficient to form stars? I gather from this article that it is all or nothing. Jupiter is supposed to be a failed star. — Preceding unsigned comment added by 74.70.122.165 (talk) 03:30, 10 January 2012 (UTC)[reply]
Stars form through gravitational collapse. I'm not clear how you concluded otherwise. Regards, RJH (talk) 04:20, 10 January 2012 (UTC)[reply]
Hi all.
Could anyone add information about known current star formations?
Also is there any current theory on the expected frequency of observable star formations?
-Sjalq
um....... just about every single nebula ever observed
Ezkerraldean
and the formation of binary star systems? Thanks. — RJH (talk) 14:52, 26 August 2006 (UTC)[reply]
The article is very vague about how quickly or slowly this whole process takes place. -- Paul Prescod —Preceding unsigned comment added by 24.84.192.12 (talk) 17:07, 2 April 2011 (UTC)[reply]
This partially relates to RJH's comment above. Wikipedia has a range of articles on different aspects of the star formation process with many of them containing excellent material. However, I found from browsing that a lot of that material doesn't seem to be in the right place and that much of it describes the broader picture of star formation rather than the specific sub-object or process mentioned in the article title. It is my opinion that star formation articles need more of a general framework. To that end I've created a nav box for this astronomy subsection to try and give some sense to these articles as whole. I don't claim its perfect, but some sort of unify construct would help focus the topic. --Jason Kirk 15:11, 17 September 2006 (UTC)[reply]
This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 10:04, 10 November 2007 (UTC)[reply]
Removed irrelevant information from pathfinder objects[edit]
I have removed 2 dot points from the pathfinder objects as they are clearly not pathfinder objects. One point was a statement which did not have a appropriate reference and the other was an unreferenced irrelevant quote. Coffeeassured (talk) 13:45, 12 April 2008 (UTC)[reply]
Regarding Pathfinder objects: what are they? The article doesn't mention the word except in this heading. Could anyone provide some explanatory text? Lancevortex (talk) 13:51, 16 September 2008 (UTC)[reply]
I removed the following addition to the lead because it is poorly explained, overly broad and completely unsubstantiated. As justification I cite WP:NOCITE under "doubtful and harmful" to the whole article, as it appears to put into doubt all of the content and yet remains utterly unjustified.
It should be noted that most current theories popular with evolutionary astronomers to explain the origins of stars fail to account for the Ideal Gas Law, which has shown to be a major obstacle.[citation needed]
Please clarify what this is intended to communicate and provide suitable reliable sources. What is an "evolutionary astronomer"? What are the theories popular with evolutionary astronomers? How do these theories fail to account for the Ideal Gas Law? In what sense is this relevant to star formation? How is it a major obstacle? Thank you.—RJH (talk) 22:09, 6 July 2009 (UTC)[reply]
In answer to the first question, apparently an "evolutionary astronomer" is one who believes in evolution and extends that belief to the field of astronomy, in contrast to a "creationist astronomer". The implication being that an "evolutionary astronomer" is any astronomer who believes in a 13.7 Ga age for the Universe, or the equivalent. The so-labeled astronomers include Carl Sagan, Harlow Shapely, Gerald Kuiper, Fred Hoyle, Robert Jastrow (ironically), John A. Eddy, William Tifft, Donald E. Brownlee and Jan Oort. Quite a group there.
I'm starting to believe that this article is being subject to the same type of creationist subtle vandalism attacks as Age of the earth. Perhaps we need to start a watch list?—RJH (talk) 22:32, 6 July 2009 (UTC)[reply]
lol. please clarify what is a creationist as i do believe creationist like Hugh Ross is also an evolutionary astronomer by your definition and we certainly don't want to rule out his expertise. Anyway it is your belief, not mine. And aren't we all vandalizing wiki ( which anybody can edit ) though i would call mine a form of Graffiti :). Correct me if im wrong though.
In answer to the second question it is actually all the theories on wiki now as the theories on wiki requires 13.7 Ga or so age for the universe. For the third question, since no one has answered this for so long I would think it would mean the equation pV=nRT whereby V is volume, p is a pressure, n is the mole, R is Regnault constant and T is temperature in Kelvin. It can be found on wiki [1]. As shown by the equation, if the temperature increases, both the volume and pressure increase while the number of atoms should be constant. As the theory of star formation such as cloud collapse requires the temperature and pressure to increase while requiring the volume to decrease, alot of energy (to cause the increase in pressure)is required to make all the gas accumulate in one place and compressing it instead of dispersing evenly throughout the universe through diffusion. So actually a star does fit with the ideal gas laws however the formation of a star without input of energy doesn't fit with the ideal gas law. The only way i believe we know that could input energy is by novas and supernovas, blackholes ejecting strong winds and galaxies colliding. However although the input of energy is very big, unless there is something to hold the cloud together while pressure is being applied so that it can be compressed until critical density is achieved, the cloud would just be blown away and scattered even more. So now to make these theories more complete we would certainly need to find a container which can contain the gas while pressure is applied until the cloud becomes a star as this certainly poses a major obstacle. I hope this also answers question 4 and 5. —Preceding unsigned comment added by 115.135.144.28 (talk) 06:49, 7 February 2011 (UTC)[reply]
Thanks, I'm familiar with the ideal gas law. What we are lacking is a citation from a reliable source that demonstrates this is a "major obstacle" with the theory. Your statement doesn't appear to account for the effect of gravity. Please see Jeans instability.—RJH (talk) 16:59, 7 February 2011 (UTC)[reply]
Thanks for the intro to Jeans instability. However if you are familiar with the ideal gas law, then you should also be familiar with pressure law. P/T = constant. Gravity causes an increase in pressure which increases the temperature. An increase in temperature would then mean an increase in volume ( charles law ) which would decrease the pressure (Boyle's law)and thus decrease temperature (pressure law) again. It is in an dynamic equilibrium. Thus gravity alone would not create a star. An external force to compress it is needed. However an external force poses some problems as firstly as i wrote above, the gas would just be more scattered and secondly, the energy would add heat energy to the gas, preventing it from collapsing as the gas would have enough energy to counter the gravitational energy which is very weak. Space is a big place and those clouds are not confined to a specific amount of space. I assume that the experiments to prove Jeans Instability was done in a lab, in a confined space and so does not reflect the behavior of clouds in space. Correct me if im wrong though. Lol what would a reliable source be ( would a so called creationist site be? :) They are certainly demonstrating against the norm theory.) ? I do think we need to do experiments in space conditions to prove star formations though. Wouldn't it be wonderful if we are at the stage whereby we could create mini stars ( im guessing as big as a basketball) from clouds of hydrogen and put them in orbit around earth? Hope i sufficiently answered you :)
Right, but it is not a closed system. Heat can escape through radiation, which allows the cloud to remain unstable under the Jeans criteria.—RJH (talk) 20:23, 9 February 2011 (UTC)[reply]
Yep, and because it is not a closed system i don't think jeans criteria apply to it as i believe it was proved under closed system experiments. —Preceding unsigned comment added by 115.133.211.72 (talk) 02:37, 10 February 2011 (UTC)[reply]
Well you're welcome to your opinion. You'll still need solid citations to include that in the article.—RJH (talk) 15:33, 10 February 2011 (UTC)[reply]
Lol, so are you :) I guess i would look somewhere else. Thanks for your time buddy :) —Preceding unsigned comment added by 115.132.184.28 (talk) 02:24, 11 February 2011 (UTC)[reply]
No one has ever observed the formation of even one of these stars. Yet there enough stars that each person on earth can personally own 11 trillion. —Preceding unsigned comment added by 70.31.124.33 (talk) 01:01, 24 July 2009 (UTC)[reply]
Given that it takes millions of years for a star to collapse to the main sequence, this is true... but not especially interesting. Astronomers have observed various the stages of the star formation sequence, then put the sequence together as a model. It works the same way for many other aspects of astronomy: the science relies on observing many examples of stellar phenomenon and then fitting models to explain them. As to your second assertion, saying that you own a star is a legally meaningless statement.—RJH (talk) 16:57, 24 July 2009 (UTC)[reply]
Yep, but a model is a model, not the real thing.
What the last guy said. Another way of putting it, is imagine you're a creature that only lives for 1 week. During your week, you observe some seeds begin to sprout. You observe some sprouts reach above the ground. You observe young sprouts grow leaves. Etc etc etc, all the way up to fully grown plants wilting their last leaf. You also understand biology, and you can run simulations of what would happen if you planted a seed in the ground and waited a year (many times longer than your life). You haven't literally observed a seed growing to a full plant, but you have observed every possible stage in the life of a plant. So you would therefore know, beyond any reasonable doubt, how plants grow, and how long it takes, etc. (Not beyond all doubt, mind you, as that's impossible for anything - but beyond all reasonable doubt) 70.54.10.114 (talk) —Preceding undated comment added 00:34, 13 August 2009 (UTC).[reply]
But we aren't a creature that lives for 1 week. Thats just pure imagination!!! Not science. though i would say that some of science advancements are motivated by imagination. By the way we know what we know because we managed to see every stage of of a plant in our life time. I don't think we can say that for stars though. We only see bright assumably new stars in the midst of clouds. We never see a star form from clouds of gas. It has never been proven lol :)
"No one has ever observed the formation of even one of these stars. Yet there enough stars that each person on earth can personally own 11 trillion." Now this is creationist trolling/vandalism. It's a qoute from http://www.youtube.com/watch?v=4jOyPQt9O4E— Preceding unsigned comment added by 62.12.14.28 (talk) 09:13, 12 July 2012 (UTC)[reply]
Does it say in the article that the process takes millions of years? —Preceding unsigned comment added by 24.84.192.12 (talk) 17:08, 2 April 2011 (UTC)[reply]
In the discovery channel, I have seen how important is supermassive black hole for the formation of stars of the galaxy. After taking out the summary of a part, I fount it like this :
It said that the gas of the early universe collapsed to form a giant black hole which immediately started feeding off gas and creating a quasar. The energy released by the quasar would create intense change in temperature causing it to condense into stars.
Could not we use it on the article. --Extra999 (talk) 12:00, 1 November 2009 (UTC)[reply]
If a suitable reference could be found that shows active supermassive black holes cause triggered star formation (or else reduce star formation), then it could be added to the 'Cloud collapse' section. I'll have a look. Thanks.—RJH (talk) 18:30, 1 November 2009 (UTC)[reply]
Okay I found a reference and added a paragraph. Is that all right?—RJH (talk) 18:48, 1 November 2009 (UTC)[reply]
I have put a small paragraph at the end of the article's text giving a link to the new discovery in 2009 of Pea galaxies.
This is relevant and gives a link to the wiki article Pea galaxy. Richard Nowell (talk) 11:47, 25 January 2010 (UTC)[reply]
Actually the relevance is quite unclear, at least to me. It is about a type of galaxy that has a high rate of star formation, but it placed in a section discussion how low or high mass stars are formed. The topic is more relevant to the Galaxy article, where content such as Starburst galaxy is discussed. Also, no offense, but the actual entry also doesn't say much of value.—RJH (talk) 19:59, 25 January 2010 (UTC)[reply]
Protostar cloud clump "cores" contract "up and to the left" along a Kelvin-Helmholtz contraction phase track, until they reach the Hayashi Limit at the "peak" of that track across the HRD. Then, protostars, having "made it over the Hayashi forbidden zone hump", then "drop straight down" at (nearly) constant surface temperature near 3000K, along the Hayashi track. Massive-enough stars (>0.5Msun) then "veer leftwards" onto Henyey tracks. Overall, densities and temperatures only increase, the entire time.66.235.38.214 (talk) 19:51, 3 November 2012 (UTC)[reply]
I don't know if asking questions in the Talk page is allowed, but here I go:
The "Protostar" section states that "This occurs when the density is about 10−13 g cm−3" I'm confused about the "cm−3". Does this mean an negative cubed? Does that make any sense? Also, shouldn't there be a "/"? Like so: "This occurs when the density is about 10−13 g / cm−3"
62.12.14.25 (talk) 09:17, 2 April 2013 (UTC)[reply]
The negative exponent means reciprocal. 1 g cm–3 = 1 g/cm3 = 1 gram per cubic centimetre. The professional astronomy literature always uses the negative exponent, but maybe the / would be better here. —Alex (ASHill | talk | contribs) 09:28, 2 April 2013 (UTC)[reply]
For a layperson the / is easier to understand. — Preceding unsigned comment added by 62.12.14.25 (talk) 11:35, 3 April 2013 (UTC)[reply]
I think that it would be a good idea to remove this section, because this topic is not particularly important to star formation. Instead, some of the results from Herschel about filamentary molecular clouds, e.g. André et al. (2010), are more important. I can try to track down the empty-space paper, and insert it as a reference elsewhere in the article. OtterAM (talk) 14:20, 10 February 2015 (UTC)[reply]
I agree. That section is just a summary of a new bit of research (interesting, to be sure), but it doesn't fit in the flow and is just way too specific for this article. Here is the diff with the text, since it might be worth putting in somewhere else (perhaps in a different article). —Alex (ASHill | talk | contribs) 14:44, 10 February 2015 (UTC)[reply]
The term "Stellar ignition" redirects to this page, even though the article doesn't seem to use any variant of the word "ignite." It might be a good idea to have a small section explaining what it means for a star to "ignite." This is actually an ambiguous term. For astronomers it's the point at which a protostar becomes a star, defined as the moment it becomes visible because it has blown away enough of the surrounding dust. In astrophysics it sometimes means the point at which the protostar has become hot enough and bright enough to slow down the rate of infalling matter so that its net mass stops increasing, thus marking the transition from protostar to pre-main-sequence star. After that it slowly begins blowing away dust and gas, although it can be a hundreds of thousands of years before this is visible from afar. And finally, ignite can mean the point at which a pre-main-sequence star begins to experience full-scale nuclear fusion and enters the main sequence. For our sun, that happened tens of millions of years after the first two events.
There is a popular misconception that all three definitions are synonymous. This article might be a good place to clear up that misconception. Zyxwv99 (talk) 15:04, 16 April 2016 (UTC)[reply]
Yes, I agree. More generally, Wikipedia needs an article about the nuclear star cluster in the Milky Way. There is a lot of material on this topic, and, maybe, if I have time, I will write/contribute to that article. OtterAM (talk) 21:47, 28 November 2017 (UTC)[reply]
It'd be great to add a History section of the theories...[edit]
I don't have the knowledge to create this section, and online searches don't readily return information such as, who was the first scientist to propose a method of star formation. What significant efforts, if any, were there prior to 1981? And of course, Richard Larson's contribution through his '81 paper in MNRAS would feature significantly in such a section, but I assume there was work before him. And it would be great to have a thumbnail sketch of significant updates to his theory. Thoughts? Bob Enyart, Denver KGOV radio host Bob Enyart, Denver KGOV radio host (talk) 00:35, 5 March 2020 (UTC)[reply]
BobEnyart, we should really have a history section here. Theories of star formation go back to the 1700s and Larsen's work is only one part of the modern theories. There is a nice presentation from 2012 on star formation that includes some of the history here. StarryGrandma (talk) 01:29, 5 March 2020 (UTC)[reply]
Please update with info about the role of superbubbles in star formation[edit]
I think it would be good to add very brief info about this, such as about / info from the study below (e.g. to section "Observations"). This is featured in 2022 in science (January):
12 January: The ~14 Myr old Local Bubble drives nearby young star formation.
Astronomers report, based on new spatial and dynamical constraints, that the Local Bubble, a ~1,000-light-years wide superbubble, is driving nearly all recent star formation near the Sun and that it originates ~14 Myr ago.[1][2]
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