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Fraser
2003-Jul-11, 05:40 PM
SUMMARY: The Hubble Space Telescope was recently used to identify the oldest extrasolar planet ever discovered. The 2.5 Jupiter mass planet was originally discovered around a pulsar in the globular cluster M4 way back in 1988; astronomers detected a regular dimming of the pulsar's radio wave emissions. By using Hubble, astronomers were better able to explain how the planet ended up around a pulsar. This discovery could reshape the current models of planetary development, which predicted that stars needed to go through at least one complete cycle to create the heavier elements that planets require.


Comments or questions about this story? Feel free to share your thoughts.

DippyHippy
2003-Jul-11, 06:27 PM
Yes, this was known about for sometime... makes you wonder if there were any Earth-like planets in the system. Thoughts of Carl Sagan's "Contact" come to mind!!

Dips

vanderL
2003-Jul-11, 09:04 PM
Okay, so we have a planet circling a 13 billion year old "white dwarf" after having been captured by a pulsar, replacing its companion white dwarf. It was detected in 1988 and it took until 2003 to spin a yarn so incredible that it reads like a fairytale.
Can someone tell me why the planet didn't form right where it is?

Fraser
2003-Jul-11, 09:14 PM
Well, the theory is that it's currently circling a pulsar, which used to be a very large star that went nova or even supernova. No planet could survive the force of the explosion, so the pulsar had to steal the planet later.

vanderL
2003-Jul-12, 05:28 PM
Thanks Fraser,

That's supposing that a nova or supernova event is an actual explosion. If these explosions are as powerful as believed their wouldn't be so many companions around pulsars/neutronstars etc and I always wonder why supernova remnants have so much structure, explosions are messy and just disperse material.
So maybe the behaviour of a star undergoing a nova doesn't destroy its planets. Or if it does the new formation of planets after a star evolves into a pulsar is also possible. Also there are a number of planets detected around pulsars, to name some:
(PSR 0329+54 (1 planet),
PSR B162026 (1 planet)
PSR 182811 (3 planets, Stairs et al., 2000)
PSR 1257+12 (3 planets)
Of course there is a bias towards finding planets around pulsars because of the way they are detected, but to simply assume they were captured is to me very much open to discussion.

alphaQ
2003-Jul-13, 06:45 PM
couple of points
RE: "lmc n49a"

No discussion link?
Why did you crop it? - many people use higher res than 1024, plz repost in full resolution.

Location is helpful in my case... and possibly other astronomers?
LMC+N049a lmcn049a.jpg 1.4225814 -1.1534057
PKS 0525-66 05h26m01.9s -66d05m07s HII

thank you,
alphaQ
http://home.earthlink.net/~alpha-quadrant/
by request only

Fraser
2003-Jul-13, 09:17 PM
Hi, I actually posted the original story for this about a week ago and I had a link to the original source on the Hubble site. They've got the picture in a zillion resolutions so you can grab it from there.

http://hubblesite.org/newscenter/archive/2...2003/20/image/a (http://hubblesite.org/newscenter/archive/2003/20/image/a)

I know that lots of people have higher screen resolutions, but most people have 1024x768 or smaller, so I was just going for a happy medium. It still scales up nicely on larger screens.

I cropped it so that it would have the right aspect ratio for a computer wallpaper. Hubble releases the images in a square shape that would have big borders on the sides if it was your wall paper.

Regarding the position, all that information was on the Hubble press information, I just didn't do a great job of connecting this wallpaper with the original story.

My apologies.

Planetwatcher
2003-Jul-14, 06:24 PM
I aggree with Frasier. The planet should have been vaporized when it's sun went either red giant, or supernova.
It causes me to wonder how they would know this particular planet is indeed the oldest of all that's been discovered so far. The oldest discovery, yes without a doubt. But I doubt this planet has always been orbiting the same star.

More likely, it was far enough away from whatever star it's parent was, that a passing nearby star, or perhaps several passing stars ripped it from it's origional orbit, and sent it hurling uncontroled, until it was captured by the one it's with now.

It's not likely to have stayed with a star that went nova unless it was very far away to begin with, and was pushed away by the explosion.
But that would raise questions about what kept it in orbit.

At any rate it's interesting to us now.

vanderL
2003-Jul-14, 09:52 PM
An example of a supernova event that didn't blow its companion to pieces is the Crab Nebula.
If theory is correct this 'explosion' was recorded by Cinese astronomers in AD 1054. The companion is located 1500 AU from the pulsar and was detected by the Hubble telescope.
Maybe it even has planets, who knows.

Bjarne
2003-Jul-16, 01:21 AM
Actually isn't "theory" but actual fact. The explosion, rather the results were indead seen and recorded by the Chinese. Their records show that it was actually visible during daylight ours and maintained a careful watch on it. As I recall from some books on the topic I have read, it would mean their lives if they weren't watchful. Ouch! Nowadays it only means a tad more than an earful but at least your head was left where it was!

As for planets. my understanding is that the possibilities are there but as always that's open to discussion.

Fraser
2003-Jul-16, 03:11 AM
There are no facts in science, only theories. There's lots of evidence to support the theory that the Chinese saw a supernova go off, but they might have had a collective hallucination.

Science's job is to keep grinding away at established beliefs to better understand how nature works.

Gravity, evolution, and relativity are all still just theories (which happen to match the evidence quite well). :-)

DippyHippy
2003-Jul-16, 03:25 AM
Perhaps the Chinese had a particularly good opium crop that year ;)

That's an interesting theory, about the planet being captured... arguments about the planet's parentage aside, bear in mind that this planet is buried inside a globular cluster and as you know, globular clusters formed at a time when it's thought there weren't the heavier elements present to form planets.

*That's* what interests me here... if that planet is as old as it's thought to be, then there could be civilisations billions of years in advance of our own.

Dips

kashi
2003-Jul-19, 07:43 AM
A book by Donald Goldsmith called "worlds unnumbered" spends a whole chapter discussing planets orbitting pulsars. It's well worth a read!

Kashi

Guest
2003-Jul-20, 03:37 AM
A collective halucination, a particularly good opium crop that year, I like those remarks.
Fortinatly science is not about guessing and supposing. Well perhaps educated guessing.

Keeping in mind the farther out into space we are looking, the farther back in time we are looking.
So the supernova the Chinese observed actually occured long before anything human ever lived on our planet.
Any advanced civilisations would be long since gone. Especaially if they were anything like us warmonging
humans who fight amoung ourselves.

I can't imagine any advanced civilisations on a planet as old as that one is supposed that could have
survived supernoves, neutron star stages, and pulsors. If they did, they are proabley too snobish to talk to us.

Planetwatcher
2003-Jul-20, 04:03 AM
Okay, that last post from unregistered was mine. I didn't know I wan't logged in.

Fraser
2003-Jul-20, 04:51 AM
Well, the Crab Nebula is 6,300 light-years away, and the supernova was seen to go off less than 1000 years ago, so that would make it 7200ish years ago that it went off... I think there were humans around then.

Sorry to geek out there. ;-)

Guest_VanderL
2003-Sep-09, 04:13 PM
How about this, on the website I mentioned in other threads www.electric-cosmos.org it is explained that the nova or supernova event is actually the event that forms a planet, so called fissioning. So in an electric model it is actually EXPECTED that stars in supernova remnants have big planets orbiting close to its 'parent' star.
This would mean that EVERY supernova/nova event recorded should yield stars with close companions, stars brown dwarves or large planets. This could be a prediction that can be verified ( or falsified).

L.