Interesting extrasolar planet discoveries

[Sporally]

OK, in that case we still have something to look forward to. But can we really be sure is has something to do with the solar system?

[baric]

What about this... Since it was a direct observation, would a large, transiting moon be detectable? Maybe one with a different spectral signature than the planet itself?

I guess that's hoping for way too much. :P

[Kullat Nunu]

Looks like Keck Telescope has imaged a three planet system. The planet mentioned in the HST daily report cannot be from this system because Keck didn't detect it. The age of direct detections has finally come.

[Kullat Nunu]

The planet Hubble saw is Fomalhaut b and is less massive than the HR 8799 trio. What a day!

[Kullat Nunu]

It appears that Fomalhaut b may have a huge ring system.

[Sporally]

The planet Hubble saw is Fomalhaut b and is less massive than the HR 8799 trio. What a day!

Amazing... And with the Hedonic Treadmill theory i'm already forgetting about it But there is something i don't get here. OK, so today it was annonced that Formalhaut B was discovered being the first direct image of an exoplanet.

I saw the press conferance and they talked a lot about the planet system with 3 planets that you linked to. And following your the link you posted just before the press conferance began i see that you (who started that post aswell) mention those three planets as if they had just been annonced today. Or am i wrong here? Those 3 were first but already had been disqualified for being exoplanets - how can it be that they haven't been mentioned before today? Do we have a total of 4 exoplanets imaged directly on the same day or what am i misunderstanding?

[George]

Wow, what a day!!! It is a done deal -- real images.

No longer is it just wiggles and Doppler of pairs, oh my! Inferences from which delicate method you use. No more whiches only. The inferred whichs only requirement is dead. Hmmmm... ok, why not... shouldn't we be singing something!

Ding dong! The which is dead,
which old which,
the wicked which,
Ding dong! The wicked which is dead.
Wake up sleepy head, rub your eyes, get out of bed
Wake up, the wicked which is dead.
She's gone where the gremlins go,
Below - below - below, yo ho.
let's open up and sing and ring the bells out
Ding Dong' the merry-oh, sing it high, sing it low.
Let them know
The wicked which is dead!

Ex-oplanets can now be seen
our own old eyes
our aided eyes
Ding Dong, it really is so keen!

[borman]

It appears that Fomalhaut b may have a huge ring system.

Instead of a ring system, I wonder if an ice body wandered within its Roche limit and was shredded and is spiralling around the planet rather than forming a stable ring system. Over the two years that the two images of Fomalhaut b was taken, it grew 1.5 times dimmer. It would be unusual for a ring system to go from face on to edge on, like a spinning coin, over just two years where the orbit of the planet is around 872 years. The ring systems in our solar system don't spin about the home planet this fast. The change from edge on to face on more often corelates with the yearly orbit if at all. But something ripped up by getting too close to the planet might leave a spiral of debries about the planet that may later either fall into the planet or form a ring system. More looks at the planet might discover whether dimming and brightening follow a regular pattern of rhythm.

[borman]

If the rhythm should be rather fast, it could be that the main planet has a moon like Enceladus that is venting ices that are the right size to be a good light refelctor. Then the dimming could be due to the moon being eclipsed by the larger planet.

[01101001]

OK, so today it was annonced that Formalhaut B was discovered being the first direct image of an exoplanet.

Visible light (as well as infrared) image?

I saw the press conferance and they talked a lot about the planet system with 3 planets that you linked to.

Infrared only image?

[borman]

One of the reasons the Hubble observation suggests Fomalhout b is a planet rather than a brown dwarf is the lack of detection of Infrared signature. This is why the other telescopes that looked at the Fomalhaut system missed the planet in earlier views. Also something as massive as a brown dwarf would have seriously disrupted the dust ring rather than just sculpting the inner ring portion. The planet is estimated to be some 3 billion kilometers inward from the ring to do the sculpting.

[timb]

Amazing... And with the Hedonic Treadmill theory i'm already forgetting about it But there is something i don't get here. OK, so today it was annonced that Formalhaut B was discovered being the first direct image of an exoplanet.

I seem to recall the first direct imaging of exoplanets being announced several times already. I think these are the first images of objects that aren't arguably brown dwarfs (well, HR 8799c/d could be over 13M_J).

Formalhaut b must be shining by the heat of its formation if its T_eff is 400K. It receives about as much energy from Formalhaut as Neptune does from the sun. Interestingly it appears to have been predicted by Alice C. Quillen in 2006: the planet has a mass between that of Neptune and that of Saturn, a semi-major axis of approximately 119 AU and longitude of periastron and eccentricity, 0.1. The values for a and e recently published by Kalas et al. agree completely, though their projected mass is considerably higher. I wonder if this gives her a share of the credit? To be fair Kalas predicted planets around Formalhaut in 2005.

I saw the press conferance and they talked a lot about the planet system with 3 planets that you linked to. And following your the link you posted just before the press conferance began i see that you (who started that post aswell) mention those three planets as if they had just been annonced today. Or am i wrong here? Those 3 were first but already had been disqualified for being exoplanets - how can it be that they haven't been mentioned before today? Do we have a total of 4 exoplanets imaged directly on the same day or what am i misunderstanding?

I can't make sense of that.

[George]

I seem to recall the first direct imaging of exoplanets being announced several times already. I think these are the first images of objects that aren't arguably brown dwarfs (well, HR 8799c/d could be over 13M_J).
... To be fair Kalas predicted planets around Formalhaut in 2005.

Today's APOD image shows an insert of the exoplanet's image taken in 2004 and 2006. I assume yesterday was the offical announcement of the first confirmed directly observed object. But am I right about this?

[Kullat Nunu]

The object orbiting the brown dwarf 2M1207 has a planetary mass, so it could be called as the first imaged extrasolar planet. However, there is no doubt that it formed like a brown dwarf, not like a planet.

There are five other bodies with masses potentially within planetary range. You can see them listed here.

Fomalhaut b is clearly the most convincing case for a true planet that has formed from a protoplanetary disk. Given the masses and distances of these new planets, it is likely that they formed from disk instabilities instead of core accretion like the planets in our Solar System.

[Dgennero]

HR 8799 animation:
http://www.washingtonpost.com/wp-dyn...111303636.html

[timb]

The object orbiting the brown dwarf 2M1207 has a planetary mass, so it could be called as the first imaged extrasolar planet. However, there is no doubt that it formed like a brown dwarf, not like a planet.

2M1207 b probably formed via fragmentation and gravitational collapse say Ducourant et al., but why would that disqualify it from being an extrasolar planet? What's crucial in the IAU draft guideline is whether it orbits a star or stellar remnant. Since it doesn't it isn't an extrasolar planet but merely a "sub-stellar object". I note, however, that astronomers typically talk about brown dwarfs as though they were dim stars in a continuum with the "real" stars: K dwarfs, M dwarfs, L dwarfs, T dwarfs... they're all just "dwarfs".

[eburacum45]

How can Fomalhaut b be that hot? Is it still very young?

[t@nn]

How can Fomalhaut b be that hot? Is it still very young?

Yes. The system is estimated to be only 200 to 300 million years old.

[George]

Yes, and the planet may only be about 100 million years of age.

[George]

Fomalhaut b is clearly the most convincing case for a true planet that has formed from a protoplanetary disk. Given the masses and distances of these new planets, it is likely that they formed from disk instabilities instead of core accretion like the planets in our Solar System.

Yes. The protoplanetary formation image of AB Aurigae further supports this idea.

2M1207 b probably formed via fragmentation and gravitational collapse say Ducourant et al., but why would that disqualify it from being an extrasolar planet?

That's yet another interesting twist in this naming saga.

[Maxx80]

Hey guys, I have a couple questions that I hope someone could answer for me...

When do you think it'll be possible to capture an actual image of an exoplanet that's much closer to it's star -- like Earth's distance from Sol? Will it ever be possible to do that? Are there any telescopes in the works capable of doing this?
Also, how detailed do you see images of these exoplanets getting in the future? Will they always be just bright specks of light?

I was just curious

[George]

The best hope for Earth-sized planets will probably be found in the Terrestrial Planet Finder mission, if approved.

There is a future mission for discovering larger exoplanets in SIM (Space Interferometry Mission)

[JonClarke]

Since the CoRoT team seems to follow closely ESA's PR tradition, don't expect to hear about it anytime soon.

ESA refer to do science by peer reviewed publication, not press release. Good on them.

Jon

[Kullat Nunu]

2M1207 b probably formed via fragmentation and gravitational collapse say Ducourant et al., but why would that disqualify it from being an extrasolar planet? What's crucial in the IAU draft guideline is whether it orbits a star or stellar remnant. Since it doesn't it isn't an extrasolar planet but merely a "sub-stellar object". I note, however, that astronomers typically talk about brown dwarfs as though they were dim stars in a continuum with the "real" stars: K dwarfs, M dwarfs, L dwarfs, T dwarfs... they're all just "dwarfs".

Calling it a sub-brown dwarf or planet is just semantics. The point is that the way it formed makes it "less real" planet than the new planets. 2M1207 is more like a binary brown dwarf than "real" planetary system. Especially when 2M1207b has its own circumstellar(?) disk.

It is sensible to use star-like definitions for brown dwarfs. After all, stars and brown dwarfs form a continuum, the border is anything but clear. Brown darfs are star-like in the sense they can fuse deuterium, and when massive brown dwarfs are young, they have spectrum similar to late type red dwarfs.

[t@nn]

Is it possible for brown dwarfs to have actual planets orbiting them?

[Drunk Vegan]

2M1207 b probably formed via fragmentation and gravitational collapse say Ducourant et al., but why would that disqualify it from being an extrasolar planet? What's crucial in the IAU draft guideline is whether it orbits a star or stellar remnant. Since it doesn't it isn't an extrasolar planet but merely a "sub-stellar object". I note, however, that astronomers typically talk about brown dwarfs as though they were dim stars in a continuum with the "real" stars: K dwarfs, M dwarfs, L dwarfs, T dwarfs... they're all just "dwarfs".

Yes. The protoplanetary formation image of AB Aurigae further supports this idea.

That's yet another interesting twist in this naming saga.

I vote we name it after Ducourant, as he's the only discoverer here who has a name that would sound cool as a planet name.

Is it possible for brown dwarfs to have actual planets orbiting them?

Yes, and there has been at least one brown dwarf discovered with a planet orbiting it.

[t@nn]

Yes, and there has been at least one brown dwarf discovered with a planet orbiting it.

Cool.

It's so amazing that only fifteen years ago we didn't have one confirmed planet around a star. Now there are so many that it's hard to keep up with all the discoveries.

[Drunk Vegan]

Does anyone have any idea what the habitable zone would be on the HR8799 system? It seems like a perfect analogue of our solar system (minus the discovery of rocky inner worlds) but I'm wondering if any terrestrials found in the system in the future will possibly be able to harbor life given that HR8799 is a blue A-type star.

[t@nn]

Does anyone have any idea what the habitable zone would be on the HR8799 system? It seems like a perfect analogue of our solar system (minus the discovery of rocky inner worlds) but I'm wondering if any terrestrials found in the system in the future will possibly be able to harbor life given that HR8799 is a blue A-type star.

I don't know what the habitable zone would like without doing some googling, but HR 8799 only has another billion years left. That might be enough time for life to evolve, but then you have the problem of, how long will it take for the rocky planets to cool enough for liquid water to be there, of bombardment by asteroids, the star starting to heat up, and so on, and assuming life evolves in a similar timeframe to Earth's you would have only single-celled organisms that would soon be fried by the star as it enters its giant stage of evolution.

[timb]

I vote we name it after Ducourant, as he's the only discoverer here who has a name that would sound cool as a planet name.



Yes, and there has been at least one brown dwarf discovered with a planet orbiting it.

That's wrong. The IAU working definition states objects with true masses below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 Jupiter masses for objects of solar metallicity) that orbit stars or stellar remnants are "planets". Brown dwarfs are not stars, therefore no object orbiting a brown dwarf is a planet. If the brown dwarf orbits a star I suppose you could argue that its satellites also orbit the star, but that would be a special case.