Talk:Magnetar
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Question
edit"Magnetars, where the decay of an extremely strong magnetic field provides the electromagnetic power."
This implies that our sun is an Magnetar. It's field collapses and goes wild every 11 years, and 'can' end in a huge x-burst. Last maximum ended with an estimated X40+ off the Western limb.
'On this day back on Nov 4, 2003, the largest Solar Flare ever recorded took place around a Sunspot then numbered 486. The flare registered X28+, but was located on the southwest limb and out of direct Earth view. Some estimates are said that the flare was actually X40+. '
http://thewatchers.adorraeli.com/2011/11/04/big-sunspot-starting-to-release-x-class-solar-flares/
Well is it a pulsar?
If this is the case, I guess it isn't much to worry about, living next to a star that is capable of bashing out X40+ flares in any direction every 11 years. 86.130.244.239 (talk) 18:16, 13 September 2014 (UTC)
- The sun is not a neutron star. A neutron star is something like a black hole but not quite.--184.63.132.236 (talk) 07:53, 15 September 2014 (UTC)
Interesting; "gamma radiation at approximately 10:51 EST. " Is this article only meant for American readers? Please use UTC in these sorts of articles and leave local time to local websites! — Preceding unsigned comment added by 2001:980:2A84:1:4461:C703:8EF:6731 (talk) 22:25, 9 July 2015 (UTC)
Known magnetars
editSomeone (from IP 212.109.130.254, only contribution since 2008) updated the number of known magnetars in the sentence at the beginning of the known magnetars without likewise updating the number of unconfirmed ones. I suspect that some of those unconfirmed ones are now part of the confirmed ones, but without a source, I can't verify. I've tagged it as citation needed; if someone has an appropriate source, could they find any source of suspected ones? Otherwise, the number of unconfirmed ones is now probably erroneous and should be deleted. - Sangrolu (talk) 12:25, 12 April 2011 (UTC)
Sentence
editThe link in the first sentence to Robert Duncan is pointing to the wrong person of this name.
- This appears to have been fixed. - Sangrolu (talk) 12:25, 12 April 2011 (UTC)
Magnetic Field Strength
editThis article says:
Magnetars are primarily characterised by their extremely powerful magnetic field, which can often reach the order of 10 gigateslas. These magnetic field's are billions of trillions of times stronger than any magnet created by man on Earth
10 gigateslas = 1010 teslas billions of trillions = an order of 109+12=1021 Implying that man-made magnetic fields have never been more powerful than 10-11 or 10 picoteslas. This is kind of ridiculous.. moreover this page claims otherwise.
Also, the tesla page claims the strongest magnetars recorded have been 10 terateslas, not gigateslas.
I'm not sure if this last fact is right or not, but I'm going to change "billions of trillions" to "millions" to make this article accurately reflect 10 gigateslas as it claims.
Caliprincess (talk) 05:21, 8 January 2008 (UTC)
- [1] says 1014 Gauss, and 104 gauss = 1 tesla, so that's 1010 or 10 trillion teslas. [2] and [3] say it's 800 trillion gauss , so that's 80 billion teslas. I suspect someone may have meant "billions or trillions"... Wnt (talk) 02:59, 28 January 2009 (UTC)
Which shows that you should leave out those Billions and Trillions in the first place. People that read these articles usually know their way in using scientific notation of numbers. In my country a trillion is something else than in English speaking countries so keep it simple and don't use them at all. — Preceding unsigned comment added by Prlwytzkowsky (talk • contribs) 22:36, 9 July 2015 (UTC)
Conservation of angular momentum
editIf the rotation slows, where is the conservation of angular momentum ? In other words, what does it 'push against' in order to slow down ?
- Magnetic braking, I searched around here but couldn't find a good article on how it works in stars, how it works in cars though gives an idea on the theory behind it (Electromagnetic brake). This website has some [4] on the stellar version. --Fxer 16:07, July 28, 2005 (UTC)
The angular momentum is ultimately carried away by beams of particles and radiation that are emitted "off-centre" -- a bit like a Katherine wheel in reverse and possibly also by spinning particles and circularly polarised radiation coming from the poles. Stevelinton (talk) 21:00, 21 August 2010 (UTC)
While cleaning up the electromagnetism category, I removed categories from Magnetar as articles are generally supposed to be in their most specific category, and Magnetars is a sub-sub-sub category of stars. I was going to, I had yet to do so, add the Category:Pulsar -- the supercat of Magnetar -- as a subcat of electromagnetic radiation, and Category:Magnetar to Magnetism, as opposed to listing individual articles within electromagnetism. The removal of Stellar Phenomena was a mistake I see now. I'm going to remove the electromagnetism and stars categories from Magnetar, and finish adding the Pular and Magnetars cats . Salsb 13:23, August 16, 2005 (UTC)
The quick and the dead
editlethal? If it were so magnetic, wouldn't one be able to stand over it, or wobble up and down between gravity and magnetism? Then wights would have a hard time falling in, though they may be smashed against the walls of their spaceship. lysdexia 12:22, 21 September 2005 (UTC)
- At 1000 km from 2 sol mass neutron star gravity is ~15 million gees. Weights will have hard time NOT falling in :)
Cleanup
editThis article requires a serious cleanup, it looks atrocious. I wish people would stop simply cut&pasting whole web pages into Wikipedia articles without reformatting, reviewing, editing, thinking... --Jquarry 02:11, 14 December 2006 (UTC)
- So I have removed the voluminous block of text which was messily cut & pasted from Robert C. Duncan's website. There was already a link to the bloody thing anyway. Sheesh. --Jquarry 02:18, 14 December 2006 (UTC)
Proposed merge from quantum electrodynamic threshold
edit- Support merge. Not enough information present to be its own article, for the time being. --Christopher Thomas 20:33, 12 April 2007 (UTC)
- Support Clearly the right idea. Shouldn't need much discussion. Gnixon 21:15, 12 April 2007 (UTC)
- Support. At this point, of course. linas 23:47, 12 April 2007 (UTC)
- Support — since I suggested this in the first place, I probably should. Anville 13:34, 13 April 2007 (UTC)
I went ahead with the merge, paraphrasing and rewriting the text because it was a copyvio from Scientific American. Anville 20:00, 13 April 2007 (UTC)
maybe just create only a cover page called wikki, and forget about any content.
So we can also forget about people who spend their free time to write something to explain to others.
I'm often wondered if you people contribute, or halt contribution.
So instead of merging / deleting, just try to write it more easier, readable by young scholars like me. —Preceding unsigned comment added by 82.217.115.69 (talk) 13:24, 15 January 2009 (UTC)
Short Lifetimes
editAn earlier version of the article stated that SGRs show violent X-ray and gamma-ray flares, and that via these flares these sources eventually exhaust their energy, at which point they become AXPs with X-ray emission only. This statement has been removed for the following reasons:
- It is correct that SGRs are phenomenologically defined by gamma-ray flares, while AXPs have relatively steady X-ray emission. However, recent events suggest that this is somewhat semantic, since when SGRs are not flaring, they look just like AXPs [5], and even the most stable and quiet AXPs have now been seen to emit SGR-like gamma-ray flares.[6]. Thus whether a source is classified as an SGR or an AXP seems to depend on how it was first discovered, rather than by any definitive evolutionary state.
- Observations suggest that the giant flares seen from SGRs do not noticeably drain their energy.[7] It rather seems to be their rapid but on-going braking of their spin period through which they lose energy.[8].
- The available evidence suggests that SGRs do not evolve into AXPs, but rather if anything the reverse sequence occurs.[9].
Tubbs334 22:39, 20 May 2007 (UTC)
- OK, thanks for clearing this up. But shouldn't the SGR & AXP articles also be updated with this new info? Or perhaps even a merge between these two? Please let me know your thoughs on this. --193.67.80.4 10:56, 22 May 2007 (UTC)
- Absolutely - most people think AXPs = SGRs = magnetars, so these should all be one article. Tubbs334 12:47, 22 May 2007 (UTC)
Galaxy Full of Magnetars
editThe statement, "The Galaxy is thus probably full of dead magnetars", is unsupported and silly. I'm removing it. --Jquarry 05:45, 23 May 2007 (UTC)
- That statement has found its way back into the article again. At least it has a reference this time. Listen, even if Duncan's very rough estimate is correct and 30 million magnetars have formed in the Milky Way... hell let's be generous and call it 100 million... That still represents just 0.1% of all stellar bodies in our galaxy. That hardly qualifies as "full of". Unless you think Japan is "full of" Caucasians, or the Earth's crust is "full of" lead. All right, this time I rewrote the statement so it at least sounds logical, even though TBH I'm not at all comfortable with Duncan's reasoning. --Jquarry 05:16, 31 July 2007 (UTC)
research
edit" "This is a breakthrough because we can now distinguish between surface and magnetospheric phenomena, Guver said. " --Emesee 06:17, 21 September 2007 (UTC)
Formation (percentages unclear)
editQuestion about unclear percentages.
"The supernova might lose 10% of its mass in the explosion [...] —maybe another 80%."
Is that "another 80% of the original mass" is lost (total 90% lost), "80% more than the original 10%" is lost (total 18% lost), or "80% of the remaining mass" is lost (total of 72% lost)? Madmadmadmage (talk) 03:33, 9 December 2007 (UTC)
Relative strength of magnetism vs. gravity
editThe model of magnetar "starquakes" seems to hint that the magnetic force in magnetars is nearly on a par with gravitational force, to cause massive rearrangements of the crust.
Another [10] says its effect on iron would be 150 million times the Earth's gravitational pull on it... but magnetar matter is perhaps 1010 times denser than iron, and under a lot more gravitational pull, so it seems like the gravity should utterly predominate?
So to put the question another way: suppose I have two magnetars near one another, stationary, north poles lined up with the spin axes and facing into one another. Is the magnetic force strong enough to make a difference (I assume they don't really bounce, though it's a cute thought), or do they crash into one another pretty much just like it wasn't even there? Wnt (talk) 03:16, 28 January 2009 (UTC)
- They rotate to align their poles N-S, and crash together, possibly forming a black hole if there is enough mass. See also Buttered cat paradox. Jehochman Talk 13:00, 28 January 2009 (UTC)
- I don't know... a spinning magnetar must have quite an angular momentum. Is the magnetic force truly enough to flip one over? Wnt (talk) 19:04, 28 January 2009 (UTC)
Known Magnetars section
editThe caption under the image under "Known magnetars" says On 27 December, 2004, a burst of gamma rays arrived in our solar system from SGR 1806-20. However, if SGR 1806-20 is 50,000 light-years away, wouldn't it be more accurate to say that it happened in 48,000 B.C.E.? ⋆ QuackOfaThousandSuns (Talk) ⋆ 23:32, 15 November 2009 (UTC)
- The quote is technically correct - the burst arrived in 2004. I think 48,000 B.C.E. is meaningless (see Light cone). Wizzy…☎ 12:15, 16 November 2009 (UTC)
There was a sentence about Earth's 'close encounter' with a magnetar giant flare, which I removed. It was some sensational quote from a tv show which really didn't make sense. Alex Deibel —Preceding undated comment added 16:22, 22 May 2013 (UTC)
Neutronium
editWhat is with this statement inside the article?
- "The density of a magnetar is such that a thimbleful of its substance, neutronium, would...."
From the neutronium article:
- "This term is very rarely used in scientific literature, for two reasons:
There is no universally agreed-upon definition for the term "neutronium".
There is considerable uncertainty over the composition of the material in the cores of neutron stars (it could be neutron-degenerate matter, strange matter, quark matter, or a variant or combination of the above).
When neutron star core material is presumed to consist mostly of free neutrons, it is typically referred to as neutron-degenerate matter in scientific literature."
So why use neutronium in this article about a neutron star? 89.137.246.65 (talk) 18:17, 30 June 2010 (UTC)Apass
- Numbered list item
An idea?
editIf you have a neutron star at the maximum possible mass (short of turning into a black hole), then neutrons can become destabilised so that we have an exchange of particles like in an electric current as they continually break up and reform, so basically an electrical star with protons instead of electrons.(Cyberia3 (talk) 14:17, 1 January 2012 (UTC))
Origins of magnetic field
editI am reverting Gark's wholesale removal of the section, and updating it. Not because I originally put it in, but it is relevant. And this user's speculation that the source is unknown while perhaps correct, goes too far to the other side of the issue proclaiming that such fields may not exist despite that inclusion of multiple known magnetars within the article. --Belg4mit (talk) 20:27, 17 January 2012 (UTC)
Section on "The anti-glitch issue"
editThis needs some rewriting, it makes several references to a scientist called "Kaspi" who is not introduced or referenced in the article. I may do this myself if I get the time.
JackStonePGD (talk) 13:23, 20 August 2013 (UTC)
- It is really odd, but apparently it's been that way for a whole year! I went ahead and made some changes[11] with as little thought as possible involved just now upon seeing this--184.63.132.236 (talk) 10:31, 9 September 2014 (UTC)
The section also includes the text "Because the strange 2012 outburst was accompanied by a slowdown, it has been called an anti-glitch" but the article currently makes no reference to a strange 2012 outburst. Presumably something got edited out and this text wasn't updated appropriately? 71.197.166.72 (talk) 01:07, 16 January 2015 (UTC)
1979 Discovery section is all about a gamma-ray burst and does not mention magnetism
editSurely this section should explain how it was found to be [due to] a magnetar ? - Rod57 (talk) 14:40, 7 April 2015 (UTC)
Additionally, the description isn't clear whether the source went supernova in BCE 3000, or whether it was / would have been observed to have gone supernova in BCE 3000. As the Large Magellanic Cloud is 163,000 light years away according to Large Magellanic Cloud, we wouldn't have detected now had it gone supernova in BCE 3000. So I assume it means we would have observed it in BCE 3000, but we should be more clear. --2604:4080:1004:202:1871:1460:D981:B5C (talk) 21:34, 19 March 2016 (UTC)
There is a serious disconnect here with these dates/distances. Somehow the Gamma radiation emitted from an object that went supernova that is 163,000 ly away made it to Earth in 4179 years? That's 39x the speed of light. 47.186.13.80 (talk) 21:16, 6 November 2020 (UTC) Anonymous
SGR J1745-2900 claims to be first recognised magnetar
editbut its not in the table here. - Rod57 (talk) 05:26, 8 April 2015 (UTC)
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"with an E/c2 mass density >10^4 times that of lead."
editWhat does this mean? Perhaps, that for a given unit of space with such a magnetic field passing through it, that there's 10,000 times the energy than would be contained in an equivalent volume of lead, given perfect conversion to energy? That's my reading but it's probably wrong (given that presumably that much energy in that much space would have very considerable mass + gravity... I'm not a physicist), clarification welcome. Thanks
92.24.38.18 (talk) 00:06, 14 April 2016 (UTC)
That's just about exactly right. The magnetic field does indeed exert a gravitational pull, although it is drawfed by that of the nearby neutron star. 138.251.195.253 (talk)
Assessment comment
editThe comment(s) below were originally left at Talk:Magnetar/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.
Ranked as mid importance, because there's a SciAm article on it. |
Last edited at 23:48, 12 April 2007 (UTC). Substituted at 22:49, 29 April 2016 (UTC)
ASASSN-15lh
editForgive me, I am not a Wikipedia editor; however, I just ran across an article which seems like it should warrant mention in this entry on magnetars, about ASASSN-15lh, which is apparently one of the brightest objects ever observed in the universe, and is quite possibly a magnetar... which led me to check this Wikipedia entry on magnetars. Anyway, I hope someone more knowledgeable can do something with this, here's the link I was reading: http://www.dailygalaxy.com/my_weblog/2016/06/mystery-object-outshines-milky-way-galaxy-by-50-times-we-dont-know-what-the-power-source-could-be-th.html 184.90.89.71 (talk) 07:18, 12 June 2016 (UTC)
External links modified
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Possible discrepancy between article and image
editThe "Neutron star types" image indicates "A teaspoon of neutron star matter would weigh 4 billion tons on Earth" and the article indicates "The density of the interior of a magnetar is such that a tablespoon of its substance would have a mass of over 100 million tons". Are magnetars 2 orders of magnitude less dense than "regular" neutron stars?
- And the Neutron Star article says that a teaspoon weighs over 5.5 x 1012 grams, or 5 million tons. One suspects that estimates differ. Interestingly, NASA comments here (https://imagine.gsfc.nasa.gov/ask_astro/neutron_star.html) that as of 2010, we did not actually know the diameter of any magnetar, meaning density is a guess anyway. IAmNitpicking (talk) 22:31, 17 November 2020 (UTC)
And above all, the mere measuring by spoons, "tea-" or "table-" is highly scientific, no trace of cheap impressing of the populace. What follows is much less important: thousands or trillions, tonnes, railway wagons or elephants, it doesn't matter.--DiHri (talk) 07:32, 13 December 2021 (UTC)
Lethal at only 1,000 km? Error?
editI am aware the cited source uses the number 1,000 km for the lethal distance from a magnetar's magnetic field. But In astronomical terms, that is no distance at all - closer than point-blank. With people concerned that a magnetar tens of thousands of light years away could end life on earth, should this number be greater, on the scale of millions, if not billions of km? It may well be correct, but such a number is laughably low for astronomy, rendering it almost non-notable. If you're only 1,000 km from a magnetar, you have bigger problems. 70.73.90.119 (talk) 15:13, 14 December 2020 (UTC)
- I believe the sources state that at that distance your body's molecular structure would be torn apart - which is "lethal" but long before that you'd be seared to a crisp from radiation. 50.111.40.79 (talk) 19:48, 1 November 2022 (UTC)
Number of Magnetars. Again.
editThere are two previous sections about this, but it came up again today when an IP editor changed the number in the article. I looked at the McGill reference to see which number was correct. The article does say "30" magnetars, but actually lists 19 in the table, and of the 30 claimed in 2014, only 24 were confirmed. The other 6 are "candidate" magnetars, or were 7 years ago. I'm not a physicist, but maybe someone could find a more recent reference? IAmNitpicking (talk) 20:05, 26 January 2021 (UTC)
GRB 790305b
editIt seems that the section on GRB 790305b is just a copy of the page for that event. Should it be switched to just a link? I don't know the conventions since I have barely edited before.
Futurama reference
editEpisode 10 of the current season of Futurama centered around magnetars. The show in general is very accurate with science references. 172.102.56.42 (talk) 01:23, 26 September 2023 (UTC)