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Ep. 28, Page 55
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Comic 2105 - Ep. 28, Page 55

18th Mar 2016, 10:58 PM in Episode 28 :: Save My Place | Load My Place
Average Rating: 5 (2 votes)

Author Notes:

smbhax 18th Mar 2016, 10:58 PM edit delete
Honza tipped me off to NASA's discovery of "super spiral" galaxies—the largest galaxies tend to be blob-like elliptical galaxies rather than neat spirals like our own, modestly sized Milky Way, but an analysis of old data, recently collated from multiple archives, found that 53 of the brightest of 800,000 nearby galaxies *do* have a spiral configuration, even though they're up to 10 times as massive and four times as broad as our own, forming stars up to 30 times as fast—they're so large, in fact, that theories of spiral galaxy formation will have to be re-assessed: typically, spiral galaxies grow by gathering cool gas from intergalactic space, but eventually their mass reaches a point where the gas comes in so fast that it heats up, disrupting the star formation process, thus naturally limiting the maximum size of spiral galaxies.

So how do these "super" spiral galaxies get so big? The scientists aren't sure, but four of the 53 that they found had two galactic nuclei (that means two supermassive black holes), indicating that they were each two galaxies that are now nearly finished merging together—so it seems that two galaxies can merge in such a way that their collective material forms neatly into one huge spiral.


image by NASA, ESA, P Crowther (University of Sheffield)

And on the subject of NASA discovering bigger than expected things out in space, Hubble found nine stars over 100 solar masses each in star cluster R136, situated 170,000 light years away in the Tarantula Nebula within the Large Magellanic Cloud, a satellite galaxy of the Milky Way. The already-known current record holder for stellar mass, star R136a1 (265 solar masses), resides in the cluster—which is just a few light years across, but easily visible in the lower right of the above Hubble photo—and three other very large stars (all over 150 solar masses) had already been known there too, since 2010, but finding five more 100+ solar mass stars (along with dozens of 50+ solar mass stars) was a real surprise, because stars this big already push the limits of what we had understood of the normal star formation process; one theory had been that the four big stars had formed from the merging of other, smaller stars, but with more than twice that many there, it seems very unlikely that they all formed from merging stars.

More factoids on these big stars: they're exceedingly bright—the nine together are 30 million times as bright as the Sun, and they "eject up to an Earth mass of material per month at a speed approaching one percent of the speed of light, resulting in extreme weight loss throughout their brief lives."


moizmad 19th Mar 2016, 12:11 PM edit delete reply
Let the lady get here first, she looks cute, then throw him overboard.
smbhax 21st Mar 2016, 7:41 PM edit delete reply
Good plan! ^_^
cattservant 22nd Mar 2016, 12:00 AM edit delete reply