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View Full Version : Hubble finds intriguing extrasolar planet in unlikely place



sol_g2v
2003-Jul-08, 08:53 PM
NASA has released this cryptic press release:

http://www.spaceref.com/news/viewpr.html?pid=12035

The details are embargoed until the Thursday press conference. Any "in-the-know" people here clue us in? 8).

Its a little weird, The Hubble Space Telescope in never used to look for planets, because even it can't see something so faint and tiny, unless its really really close. I know it was supposed to be used to look for planets around Alpha Centauri a little while ago.

Doodler
2003-Jul-08, 09:25 PM
It either snagged a one-in-a-trillion shot or was used to detect the wobble with a secondary camera :o

Crimson
2003-Jul-08, 09:26 PM
Well, Harvey Richer does globular clusters, doesn't he? And globular clusters would not be expected to have planets, because of their low metallicities. So maybe....

ToSeek
2003-Jul-08, 09:35 PM
Sigurdsson has written a paper (http://www.astro.psu.edu/users/steinn/preprints/abs2.html) on the possibliity of finding planets around pulsars in globular clusters.

sol_g2v
2003-Jul-08, 09:45 PM
Yeah, I think they found a planet in a GBC, maybe by microlensing. That would be unlikely, though not necessarily intriguing.

tracer
2003-Jul-08, 10:49 PM
Its a little weird, The Hubble Space Telescope in never used to look for planets, because even it can't see something so faint and tiny, unless its really really close.
However, the HST has been used (successfully) to find planetary system formation disks around other stars.

The Bad Astronomer
2003-Jul-10, 05:58 PM
However, the HST has been used (successfully) to find planetary system formation disks around other stars.

Heh, yeah, I was involved with several of those projects. However, it is now 5 minutes before air time on NASA TV, and the splash page says "Oldest Known Planet" so it does indeed sound like we have a globular planet here. We'll know in a few minutes.

NASA TV link (http://www.nasa.gov/ram/35037main_.ram)

The Bad Astronomer
2003-Jul-10, 06:16 PM
Yup. The planet is in M4, a globular cluster in Scorpius. It orbits a binary system composed of a white dwarf/neutron star pair. The pulsar has been known for some time through radio observations, and from the change in the pulse timing it was known that there were two companions. What Hubble did was find the white dwarf companion, which characterizes the whole system. By understanding the WD, it becomes possible to understand the orbit of the planet as well.

One scientist conjectures that the WD/planet system formed separately, and become bound with the neutron star a few billion years ago. They present some evidence for this, which is compelling, though keeping the planet in orbit is hard in such a merger scenario. I'll be curious to see the repercussions of this in the journals!

I am sure that soon there will be a page about this at the Hubble website (http://www.stsci.edu). Stay tuned.

The Bad Astronomer
2003-Jul-10, 06:41 PM
Ah, Here you go (http://hubblesite.org/newscenter/archive/2003/19/).

sol_g2v
2003-Jul-10, 08:00 PM
Beautiful bit of astronomical detective work. 13 Billion year old planet! What a wild ride. The full-res artist rendition at the hubblesite is fantastic. Space.com also has a huge writeup here here. (http://www.space.com/scienceastronomy/oldest_planet_030710-1.html)

sol_g2v
2003-Jul-12, 08:54 AM
Here's (http://www.thorsett.org/papers/srh+03.pdf) the actual paper published in Science

Chip
2003-Jul-12, 09:11 AM
Would large, gaseous Jupiter-like planets (which this likely is,) have a lower metallicity than rocky Mars or Earth-like planets? Or does theory state that planet formation in general require high metallicity from the parent star regardless of what kinds of planets form? Just curious.

eburacum45
2003-Jul-12, 09:15 AM
So why don't globular clusters and other homogenous bodies of stars experience waves of stellar formation?
They obviously have supernova events...
could this planet not be formed from the dust of such an event, like ours is?

tracer
2003-Aug-29, 01:03 AM
So why don't globular clusters and other homogenous bodies of stars experience waves of stellar formation?
They obviously have supernova events...
The thinking is -- or at least, the thinking was when I was in that undergraduate astro class 14 years ago -- that any gas and dust clouds in a globular cluster are "strained" out whenever it passes through the galactic plane. So, all of the heavy-element-enriched gas-and-dust clouds that came whooshing out of supernovae in a globular cluster got swept up by the rest of the galaxy before they had a chance to settle down and form new stars. The fact that all the stars capable of going supernova would have done so in the first few million years of the cluster's lifetime only compounds the problem.

eburacum45
2003-Aug-29, 01:56 AM
Excellent answer; thank you.
And I wouldn't waste too much time looking for habitable objects in clusters then, given the chance.
No dust and no new stars implies few planets.

BobtheEnforcer
2003-Aug-29, 06:13 AM
So...can't we assume that this planet is a gas planet? If its 13 billion years old and in a globular cluster, there wouldn't have been any supernova's (or very few) to produce heavier rocky/metal elements?

tracer
2003-Aug-29, 05:43 PM
No dust and no new stars implies few planets.
Not nececelery. It merely implies that the planets which do exist will be composed almost entirely out of hydrogen and helium. For all we know, there could be scads of these metal-poor gasballs whizzing around the various stars in a globular cluster.