Move over, Lord Vader. A group of astroboffins using Chile's high-desert Atacama Large Millimeter/submillimeter Array (ALMA) have peered into the Orion Nebula's planetary nursery and discovered that massively powerful stars can be so intense that they blow away any chance of planets forming around new stars being born in their …
Very cool stuff - but...
"...C'mon now, let's all join in a reverent chorus of Sir Elton Hercules John's "The Circle of Life""
Ooh. Lets, er, not.
(nothing to do with me crying when Mufasa dies, every time)
protodisks would be irrelevant..
Given that those big hulking neighbours will really rain on the parade of any planetary system "near" them when they inevitably go supernova.
Still.. pretty cool to see that nowadays we can actually image the things Theory predicted to be around.
about 1,000 astronomical units in diameter
I can't even think of a word to do justice to its size!
But with all that mass, how does it not immediately collapse into a black hole?
I'd guess the stuff is in orbit around the central star and therefore not falling straight into it. Just like Earth didn't fall into the sun.
Re: I can't even think of a word to do justice to its size!
Re: Orbital velocity
Plus the disk is not very dense -- it's hard vacuum to anyone other than an astronomer. There might be only a few dozen solar masses of gas and dust in the disk, most of which would have been blown away in the few million years after its star ignited anyway.
"I can't even think of a word to do justice to its size!"
"Big". HTH, HAND.
To answer your question: mass isn't enough to create a black hole, you need density as well. If you want to know more about it, watch the 1979 Disney movie The Black Hole. You'll learn nothing about black holes, but it's a really good movie and you'll enjoy yourself a lot more than if you'd spent the same length of time poring over scientific textbooks for relatively useless trivia.
>I can't even think of a word to do justice to its size!
Numbers aren't good enough for the likes of you? Is that it?
Re: I can't even think of a word to do justice to its size
and yet, if I calculated correctly, that's only about 15/1000 of a light year.
obligatory Douglas Adams quote: "Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."
The Oort cloud is thought to be up to 100,000AU's in diameter.
Not just a long way to the chemist.
If you took all the nuclear DNA (ignore mitochondrial DNA) from a person and teased it out into a straight line then
a) the person would be dead
b) it would stretch for approximately 13AU
Re: it would stretch for approximately 13AU
You can't just come out with ideas like that without due warning. My thought processes are now hiding in a corner and refusing to consider anything stranger than the next door neighbour.
"But with all that mass, how does it not immediately collapse into a black hole?"
For the same reason the Milky Way doesn't collapse into a black hole: it's all in orbit. Black holes form when a lot of fairly stationary mass (e.g., a star) finds a reason to implode (like a cessation of fusion heat that was keeping it inflated.) The magical moment happens when a sufficient portion of the star's mass gets inside a certain radius.
If everything stays in orbit (or gets blasted away by a neighboring O-type star that can't contain its hot gaseous emissions), then you don't get a black hole.
You'll being eating your words in a few million years time when Theta1 Orionis C blows up. Not due to "The Force" so much, but due to "The Physics".
That matter won't have time to congeal into planets
Presumably because of the temperature of the gas and dust? It's clear that you can get the density to form big stars.
While the centre of the nebula seems quite unfridly to accretion discs the light pressure will be less away from the core, so you might perhaps get planet formation in the outer reaches of the nebula?
tenth of a light year?
a tenth of a light year away or closer
Why can't you just write "about a light month" like everyone else does?
Or "a couple of milli-Kessels"?
Re: tenth of a light year?
A down-vote from the humor-impaired is a compliment, I believe.
Re: Or "a couple of milli-Kessels"?
I like Star Wars, but Lucas really should have had someone who passed Astro 1 to explain to him how stupid that line was. No amount of re-interpreting or treknology-ing or it will fix it.
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