[X] My Assistant

[dtolman]

Hubble may be on the blink, but the data analysis and discoveries roll on:

Hubble Announces A Major Extrasolar Planet Discovery


WASHINGTON -- NASA will hold a Science Update to report on a significant discovery about planets orbiting other stars at 2:30 p.m. EST, Thursday, Nov. 13, in NASA's James E. Webb auditorium. This unique discovery, made by the Hubble Space Telescope's Advance Camera for Surveys instrument, also will be featured in the Nov. 14 issue of the journal Science.

The briefing participants are:
-- Ed Weiler, associate administrator of NASA's Science Mission Directorate in Washington
-- Sara Seager, associate professor of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Mass.
-- Paul Kalas, assistant adjunct professor, Physics and Astronomy Department, University of California at Berkeley.
-- Mark Clampin, James Webb Space Telescope Observatory project scientist, NASA's Goddard Space Flight Center, Greenbelt, Md.
-- Marc Kuchner, exoplanet scientist, Astrophysics Science Division, NASA's Goddard Space Flight Center, Greenbelt, Md.

Reporters attending the event will have an opportunity to ask questions. News media representatives not attending will be able to ask questions via teleconference. To participate in the teleconference, reporters must email a request for dial-in information that includes their media affiliation and telephone number to J.D. Harrington at j.d.harrington@nasa.gov by 1 p.m. EST, Nov. 13.

[dtolman]

Feel stupid replying to myself... but I can't resist. I bet they're announcing a planet around Fomalhaut. Hope I'm not stealing anyone's thunder if I'm right

[volcanopele]

Good guess me thinks. Looking at the research interests of the panelists, we got someone interested in transiting planets, another interested in circumstellar disks, and another interested in possible white dwarf planets. A transiting planet around a white dwarf + circumstellar disk

[Hungry4info]

We've also been following this story here:
http://solar-flux.forumandco.com/extrasola...hubble-t164.htm

We may have got the possible discovery reduced down to a list of possible star systems, based on looking at what the ACS has been targeted at over the length of this year

I bet they're announcing a planet around Fomalhaut.

That wouldn't make much sense. As the instrument was the ACS, it's most likely transit related. Fomalhaut's circumstellar disk is inclined at a non-transiting angle. If planets are forming in the Fomalhaut system, they should be at the same inclination as the disk, as observed at Eps Eri.

A transiting planet around a white dwarf

Oohh... that's really unlikely. The chances of a planet transiting its star drop quickly with distance from the star. White dwarfs used to be giants, so no short-period planets are expected to exist around white dwarfs. Any planets orbiting white dwarfs would likely have long periods and large separations, making observing them in transit extremely difficult. Another factor is the diameter of the star. White dwarfs aren't exactly large, making the chances of finding a transiting planet around them even smaller. Though, if a gas planet "transits" a white dwarf, it would be more like an eclipse. White dwarf just disappears, so it would be really obvious.

I'm not saying that either of these cases are impossible though. It would really brighten my day if one of these turned out to be the discovery.

[belleraphon1]

Thanks for posting.... I'll be watching this for sure....

Just been navigating through the exoplanet encyclopedia at http://exoplanet.eu/... excellent site...

Kuchner has co-authored several papers regarding white dwarf stars and exozodiacal dust including a rebently puplished paper entitled "The Detectability of Exo-Earths and Super-Earths Via Resonant
Signatures in Exozodiacal Clouds" http://fr.arxiv.org/PS_cache/arxiv/pdf/0810/0810.2702v1.pdf

Seager has co-authored many papers regarding super-earth class planets as well as theorectical modeling of mass-raduis relationships for exoplanets... see "MASS-RADIUS RELATIONSHIPS FOR SOLID EXOPLANETS"
http://fr.arxiv.org/PS_cache/arxiv/pdf/0707/0707.2895v1.pdf

Kalas has many co-authored papers regarding debris disks around other stars..

Clampin, ditto on circumstellar dust creation...

Being this is a Hubble ACS discovery I would put my money on something to do with debris disks and exoplanet detection.

For those interested goto http://fr.arxiv.org/abs/0808.2754 and use the search engine on the upper right ...
input a name or subject to navigate through the astrophysics catalog of papers... I find this a wonderful resource...

Craig

[Vultur]

Well, we have lots of exoplanets, so it's got to be something unique - not "just" another hot Jupiter. It says "a significant discovery about planets orbiting other stars" - maybe some new information on how they're formed? A complex solar system like our own? A potential life-bearing world?

[Pavel]

Maybe a double planet? Just a wild guess.

[dtolman]

That wouldn't make much sense. As the instrument was the ACS, it's most likely transit related. Fomalhaut's circumstellar disk is inclined at a non-transiting angle. If planets are forming in the Fomalhaut system, they should be at the same inclination as the disk, as observed at Eps Eri.

Hi,
Reason I mention Fomalhaut, is that Paul Kalas's main project with the HST is the Fomalhaut Deep Field. It is also his only listed research project with the HST for extrasolar planets. He presented during 2005 about his observations of it (Evidence for A Planetary System Sculpting Fomalhaut's Dust Belt ). Perhaps this is a new discovery based off a pre-2008 observation campaign?

Addendum - also Paul Kalas has done previous observing campaigns for planets (technically "sub-stellar companion") using the ACS coronagraph. I assume this is based off an observation run he made post 2005.

Daniel

[Fran Ontanaya]

Maybe something about ring systems around many exoplanets.

[Guest_Enceladus75_*]

Well, with the detection of planets around other stars pretty much routine these days, it has to be something special, like:

The smallest planet yet found so far - maybe down to Earth size or a bit larger;

The detailed composition of an extrasolar planet's atmospere or maybe even surface;

The transit of a small extrasolar planet, or

The first detection of a large moon of an extrasolar planet.

[Vultur]

I assume it can't be anything REALLY earth-shattering (a world emitting radio messages or something ) or they'd be lining up the world media.

[imipak]

IIRC the ACS has seen rings, i.e., a disk where the central area has presumably been cleared by orbiting bodies. Would it be able to image a ring system with two or more cleared zones?

[Del Palmer]

Perhaps this is a new discovery based off a pre-2008 observation campaign?

Unless we're talking SBC, then the observations would have to predate Jan 2007, when ACS/WFC and HRC stopped working. If we are talking SBC, my guess would be lifetimes of disks (SBC has been very busy observing photoevaporation effects on disks).

[Juramike]

How about a transiting "exothingy" deeply embedded in a circumstellar disk?

Something early on in the process of clearing out it's zone. [And no further comment from me regarding definitions]
I'd think that'd be a pretty huge discovery.

-Mike

[nprev]

I think any sort of exoplanet-related detection by HST is always pretty major, and it'll be of great interest to enthusiasts such as ourselves. However, as always, be prepared to be underwhelmed... ...doubt that whatever it is will be of much interest to the mass media.

[Guest_Oersted_*]

Maybe an Earth-size planet within the band that would make liquid water on the surface possible?

[Hungry4info]

I think any sort of exoplanet-related detection by HST is always pretty major, and it'll be of great interest to enthusiasts such as ourselves. However, as always, be prepared to be underwhelmed... ...doubt that whatever it is will be of much interest to the mass media.

Last HST exoplanet discovery release was the SWEEPS planets back in Oct 2006. Only two of which were confirmed, the rest are still waiting sensitive enough radial velocity measurements (host stars are too dim, leading to low signal-to-noise ratios). Both planets were run-of-the-mill hot Jupiters. A significant underwhelming.

An Earth-mass planet would certainly be nice, but I doubt one can be conclusively found. Radial velocity sensitivity isn't quite that high yet. An Earth-radius planet might be detectable with HST, but I doubt it. Maybe if the host star is small, like a red dwarf or something. CoRoT is better suited to detect terrestrial exoplanets.

[infocat13]

In the comming years I am hoping for a super jupiter in the goldilocks zone with pretty earth size moons with water in the spectra of the moons atmoshere!

[Pavel]

Some interesting speculations here:
http://scienceblogs.com/catdynamics/2008/1...s_far_to_go.php

[Fran Ontanaya]

*jumps on the (embargo) bandwagon*

I've seen the post of a blogger that actually catched it the day after.

[Hungry4info]

Some have already figured out what the discovery is. The documentation is, after all, publicly available.

[infocat13]

Some have already figured out what the discovery is. The documentation is, after all, publicly available.

Ha hell I correctly guessed the 10th planet discovery announcemet by 10 hours at yahoo groups..........................not that i know any thing but was wacthing........................and sometimes I do know something

[max]

Astronomers capture first images of multi-planet system around another star

A team of researchers from Canada, the US, and the UK has become the first to capture images of a multi-planet system around a normal star, much like our own solar system.

http://www.stfc.ac.uk/PMC/PRel/STFC/Gemini.aspx

This is from the STFC RSS feed, the URI doesn't work yet.

[Fran Ontanaya]

That may refer to this news:

http://www.keckobservatory.org/printer_fri...with.php?id=228

[tasp]

(probably not related to this pending announcement)

I have been expecting light curve data on transiting exo-planets to eventually reveal either a binary planet, a ringed planet, or one that is enmooned. (or let's go for broke, and maybe have one object exhibit multiple characteristics)

Seems like I saw speculation somewhere that 'steps' in the light curve for these objects would indicate rings and such, if they were large enough, and unless there is some dynamical effect of close stellar proximity that might disrupt such features, I am hopeful we get to 'see' something along these lines sooner or later. A silicate type moon (like Io) should be refractory enough to withstand large stellar flux, but if the 'mechanism' that puts these large planets in close proximity to their host stars also affects attendant moon orbits, maybe we never get to examine an example of this.

[dtolman]

That may refer to this news:

http://www.keckobservatory.org/printer_fri...with.php?id=228

I think that actually may be a competing announcement. Ouch! It'll be hard for Hubble to top that - an actual image of a 3 planet system!

[jamescanvin]

That may refer to this news:

Wow! that is impressive - dtolman is right, the Hubble announcement is going to have a hard time beating this.

The image links don't work in the link Fran gave, try here instead

In fact I think that image deserves to be inline.


EDIT: It looks like the Keck press release and images has been taken down.

[ngunn]

I agree. You beat me to that image post by 5 minutes James! This is indeed the beginning of the future.

[Pavel]

Hints at "the second week of September" on catdynamics make me think that it refers to "episodic accretion of cometary material"

[ElkGroveDan]

Wow. This makes me wonder what kind of technology and innovation we will have in 50 years and what we might see then.

[ElkGroveDan]

EDIT: It looks like the Keck press release and images has been taken down.

Maybe someone can dig the image out of their cache. I can't figure out where anything is on the Vista system I'm running here.

[Hungry4info]

I printed it out, but didn't think to save it to the hard drive. =(.

And no, the HST release isn't as good as this Keck release.

[dtolman]

Looks like Keck pulled the whole thing off the website - maybe the didn't realize that the Hubble announcement was today, and felt bad about stepping on toes?

[Tman]

From another source:

Attached thumbnail(s)

 

[dtolman]

An overseas press site screwed up the embargo... If you want to be spoiled:
Its gratifying to know that the research and data parsing skills they taught me in High School still aren't failing me, my initial prediction was spot on. Hubble snaps a pic of a planet orbiting Fomalhaut during Paul Kalas's observation campaign. Goto google news, and search for the terms keck and extrasolar.

Oh those poor Hubble scientists... definitely a cool announcement but man, Keck really stole their thunder.

For Paul Kalas's sake, I'll pretend not to know about the Keck one, so his personal research triumph can have a few moments to shine. It really is a great discovery, and he'll always be able to say that he got in this particular first...

[Stu]

Three planets circling a naked eye star I'll be able to see from my backyard tonight... wonderful, just wonderful...

GLORIOUS times we live in!

[Stu]

Some more on this from Phil P...

[dtolman]

The gemini press release is up - better than the late Keck one, imho.

http://www.gemini.edu/node/11151

...

and the Hubble announcement is up now too!
http://www.nasa.gov/mission_pages/hubble/s.../fomalhaut.html


Daniel

[Pavel]

This summarizes all announcements:
http://www.space.com/scienceastronomy/0811...-exoplanet.html

[john_s]

I'd say the Hubble discovery is just as spectacular as the Keck/Gemini discovery. It's a smaller planet (3 Jupiter masses rather than 6-10 Jupiter masses for the Keck/Gemini planets, assuming all those numbers are reliable), and is thus more like those in our own solar system, and it's seen in reflected light rather than by its internal heat radiation, which provides a whole different way to study it (if it has water ice rings, for instance, we might be able to detect them spectroscopically).

Both results are amazing, anyway.

John.

[stevesliva]

Is that Formalhaut or the Eye of Sauron?

Very cool discoveries.

[ngunn]

So we have a system of 3 hot planets detected by their intrinsic IR (Gemini/Keck), and a single (somewhat smaller?) planet imaged by the visible light from it's parent star, but probably with a large contribution from light scattered by a surrounding moon-forming disc or ring close to the planet. One has to question whether this planet could have been detected by light reflected from it's globe alone.

Has anyone got information on the object's visual magnitude, or of what magnitude would have been expected from simple reflection off a globe at that distance from Fomalhaut?

These are both giant steps, but there are still plenty of 'firsts' left for others to claim in future as more wonderful results come in.

[Stu]

All the Hbbble images (and videos) of Fomalhaut you could want, right here...

http://www.spacetelescope.org/news/html/heic0821.html

[Hungry4info]

Well I was certainly wrong.
I underestimated HST. I wasn't aware it could do that
Very awesome discovery (both of them).

[nprev]

Delighted to be not at all underwhelmed!!! We have all at least lived long enough to actually see the worlds of other stars, the first such in all our history. THAT is humbling.

[bcory]

Truly historic

[Juramike]

Very cool! It made the "top story" at CNN (as of 10 PM EST)!
http://www.cnn.com/

Permalink(?): http://www.cnn.com/2008/TECH/space/11/13/n...nets/index.html

[brellis]

I thought we'd have to wait until ACS was repaired to get a direct image of an extrasolar planet. Who knew, the shots had been taken years ago!

[ngunn]

Has anyone got information on the object's visual magnitude, or of what magnitude would have been expected from simple reflection off a globe at that distance from Fomalhaut?

Thought I'd have a bash at the second question myself. I make the simplistic assumtion that the planet's globe appears the same brightness as Neptune's. (It may well be larger than Neptune and Fomalhaut's light is brighter than our Sun's, but it orbits considerably further out.) So, take Neptune to the distance of Fomalhaut and my back of the envelope estimate yields a visual magnitude of (edit) 29 or 30.

[Tman]

In this science paper http://www.spacetelescope.org/news/science...er/kalas_ms.pdf from page 13/14 there're explanations about the Photometry.

If I get it right they came to the result that our Saturn system would have a magnitude of 29.5 or about 4.5 mag too faint
compared to what is actually observed.

[ngunn]

This release states that Fomalhaut b is 'one billion times fainter' than it's star.

http://hubblesite.org/newscenter/archive/r...s/2008/39/full/

That amounts to a difference of about 22 magnitudes, making the magnitude of the observed object around 23. If my figures are correct that's over a hundred times brighter than one would expect a 'naked' planet to appear by reflected light. That would mean that it is the inferred proto-galilean disc around the planet which has been directly imaged, making this an indirect observation of the planet itself. Can anybody clarify this issue - or spot the howling blunder in my calculations?

Of course I don't seek to detract in any way from the magnificent achievement that this observation represents.

[ngunn]

Aah! Thanks a million Tman - we posted simultaneously there. I couldn't find the full article myself. (EDIT - of course I could have just followed the links from Stu's post (!) ) So it seems my back-of-the-envelope was not too far off. In that case one must question the appropriateness of the press release headline "Hubble Directly Observes Planet . . . ".

[Mongo]

Several papers are up on arXiv:

Optical Images of an Exosolar Planet 25 Light Years from Earth

Paul Kalas, James R. Graham, Eugene Chiang, Michael P. Fitzgerald, Mark Clampin, Edwin S. Kite, Karl Stapelfeldt, Christian Marois, John Krist

Fomalhaut is a bright star 7.7 parsecs (25 light years) from Earth that harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate, Fomalhaut b. In the plane of the belt, Fomalhaut b lies approximately 119 astronomical units (AU) from the star, and within 18 AU of the dust belt. We detect counterclockwise orbital motion using Hubble Space Telescope observations separated by 1.73 years. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter for the belt to avoid gravitational disruption. The flux detected at 800 nm is also consistent with that of a planet with mass no greater than a few times that of Jupiter. The brightness at 600 nm and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observed variability of unknown origin at 600 nm.

Fomalhaut's Debris Disk and Planet: Constraining the Mass of Fomalhaut b From Disk Morphology

E. Chiang, E. Kite, P. Kalas, J. R. Graham, M. Clampin

Following the optical imaging of the exoplanet candidate Fomalhaut b (Fom B ), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. We find that to not disrupt the belt, Fom b must have a mass < 3 Jupiter masses. Previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Preliminary analysis of Fom b's space velocity does not bear this out. The disagreement might be resolved by having additional perturbers in the Fomalhaut system, for which there is independent evidence from the star's anomalous Hipparcos acceleration. Our upper mass limit of 3 Jupiter masses for Fom b is not affected by these considerations. The belt contains at least 3 Earth masses of solids that are grinding down to dust. Such a large mass in solids is consistent with Fom b having formed in situ.

From the first paper:

Though faint, Fomalhaut b is still one hundred times brighter than reflected light from a Jupiter-like planet at that radius from Fomalhaut.

Comparison between our photometric data and model planet atmosphere spectra indicate that Fomalhaut b may be a cooling Jovian-mass exoplanet with age 100-300 Myr. A planet atmosphere model with effective temperature Teff = 400 K and radius 1.2 RJ , for which the bolometric luminosity is 3.4 × 10−7 L⊙, reproduces the observed 0.8 μm flux.

Choosing a 400 K, 46 m s−2, 5× solar abundance model as a baseline, we can investigate the effects of gravity and composition using theoretical exoplanet model spectra. The elevated abundance set is chosen to be representative of solar system gas giants. The temperature and gravity of this model are a good match to a 200 Myr, 2.5 MJ exoplanet.

From 0.6 to 0.8 μm, Fomalhaut b is bluer than the models predict. Furthermore, between 2004 and 2006 Fomalhaut b became fainter by ∼0.5 mag at 0.6 μm . Photometric variability and excess optical emission cannot be explained by exoplanet thermal radiation alone. The 0.6 μm flux might be contaminated by H emission that is detected from brown dwarfs. Variable H emission might arise from a hot planetary chromosphere heated by vigorous internal convection, or trace hot gas at the inner boundary of a circumplanetary accretion disk, by analogy with magnetospheric emission from accreting T Tauri stars. If a circumplanetary disk is extended, the starlight it reflects might contribute to the flux detected at 0.6 and 0.8 μm. To explain our observed fluxes requires a disk radius ∼ 20−40 RJ, comparable to the orbital radii of Jupiter’s Galilean satellites.

As remarkably distant as Fomalhaut b is from its star, the planet might have formed in situ. The dust belt of Fomalhaut contains three Earth masses of solids in its largest collisional parent bodies. Adding enough gas to bring this material to cosmic composition would imply a minimum primordial disk mass of 1 MJ, comparable to the upper mass limit of Fomalhaut b. Alternatively, the planet might have migrated outward by interacting with its parent disk, or by gravitationally scattering off another planet in the system and having its eccentricity mildly damped by dynamical friction with surrounding disk material.

Bill

[gpurcell]

What I find particularly exciting about this discovery is that the imaged planet is so close to ours. It is within the realm of possibility to image a century long campaign of surveying the system, learning more about it, and eventually sending a multi-generational probe sent to investigate it and establish ground truths.

What a day to be alive!

[Juramike]

If a circumplanetary disk is extended, the starlight it reflects might contribute to the flux detected at 0.6 and 0.8 μm. To explain our observed fluxes requires a disk radius ∼ 20−40 RJ, comparable to the orbital radii of Jupiter’s Galilean satellites.

Are those calculations for a rocky circumplanetary disk or for a high albedo icy ring?

(Would a ring be stable out at the orbital radii of the Galilean satellites????)

[Mongo]

Are those calculations for a rocky circumplanetary disk or for a high albedo icy ring?

(Would a ring be stable out at the orbital radii of the Galilean satellites????)

From the paper:

Now we consider that the planet is surrounded by dust grains analogous to circumplanetary rings. Since this is a flattened disk, the geometric cross section scales as cos(i), where i is the inclination to the line of sight (i = 0o is a face-on orientation). Consider that the main, optically thick rings of Saturn extend out to Saturn’s Roche radius, or about 2 planetary radii. If Fomalhaut b also harbored a ring system extending to its Roche radius, then p would be replaced by the ring cross section pr ∼ p × 22 × cos(66o) ∼ 1.6p. Assuming again Qs = 0.5, the apparent magnitude of the system would be mpr = 29.5 mag, or about 4.5 mag too faint compared to what is actually observed.

To make up for this shortcoming, the scattering surface area of the planet+ring system would have to increase by yet another factor of ∼60. This would correspond to about ∼16 planetary radii. If the effective albedo of the ring particles is closer to 0.1—and in fact outer solar system albedoes are typically this low—then the rings must extend to ∼35 planetary radii. An optically thick ring system that is 16–35 planetary radii large is better described as a protosatellite, circumplanetary disk. For example, the outermost Galilean satellite of Jupiter, Callisto, has a planetocentric distance of about ∼27 Jupiter radii. Regular satellites have prograde motion that indicates formation in situ around the planet.

So an icy ring system with near 100% average albedo would need to extend to ~16 planetary radii, while a dark, dusty ring system with average albedo near 10% would need to extend to ~35 planetary radii.

It is implied that a Saturnian-type ring system is stable only out to the Roche radius, and a disk extending out to 10-20 times the Roche radius (as in this case) must be unstable and will collapse into larger solid satellites.

[Fran Ontanaya]

It will be interesting to know if the reflected light is polarized and how.

[infocat13]

I have emails back and forth with NASA scientists on the upcomming kepler mission I had asked if the transiting jupiter with nice large moons could be detected and it is believed it can!
I have the science magazines articles on the discovery from my membership but they have a copyright! there are comments about nulling starlight and how they think they have detected a massive ring around Folmahuet B

another science article discuses nulling the star and the dust spetra to arrive at the spetra or temperature of the planet and then extrapolate the age of the new born planet and its mass.

the effect of the planet on folmahuets dust bands also arrives at the mass of the planet and of the dust bands.


so...............................no brown drarfs here

[Vultur]

I wish they would give exoplanets "real" names, not just letters - a star as bright and well-known as Fomalhaut should have named planets.

[edwinkite]

I wish they would give exoplanets "real" names, not just letters - a star as bright and well-known as Fomalhaut should have named planets.

I agree. I think a good scheme would be naming extrasolar planets after fictional planets, with a restriction to books by dead authors.

However, wIser heads than mine point out that the expected discovery rate once Kepler and Gemini Planet Imager are running is so high that we would soon run out of appropriately dignified names. I have no problem with calling a small asteroid after a minor baseball player, but it seems wrong to do that to a giant planet.

A compromise might be to name planets orbiting stars closer than, say, 10 or 20 pc - the destinations - and leave the more distant worlds as letters for the moment.

(I am a junior member of the Fomalhaut science team and an author on both the theory & the observation papers).

- Edwin

[MizarKey]

...(I am a junior member of the Fomalhaut science team and an author on both the theory & the observation papers).

- Edwin

Edwin, welcome to UMSF, and congratulations! What an exciting time in astronomy and the exploration of space. We've come a long way in the 30 years I've been interested in the sky. Hopefully we'll figure a way to send unmanned probes out fast enough to get 'on site' data within my lifetime.

[nprev]

Welcome, Ed! Nosy question here: Any details on the future observation campaign? (Wondering here if you guys plan to sweep all the nearby stars in any particular order). Also, what's the anticipated max detection distance for non-transiting superjovians (i.e, 150ly or so?)

Re the naming of names: I think keeping the current IAU convention would be fine for now. Once we can characterize these worlds would be the time for formal naming, IMHO, and surely SF provides a rich source. And just as a postscript, I certainly hope that when we map out an entire solar system the IAU will adopt the classic nomenclature of science fiction by assigning Roman numerals for each world based on its orbital radius or periastron, smallest to largest. The disadvantage of the letter convention is that it's based on order of discovery and therefore there's no continuity of order between systems.

[tdemko]

I wish they would give exoplanets "real" names, not just letters - a star as bright and well-known as Fomalhaut should have named planets.

The polite thing to do would be to refer to an exoplanet by the name the residents use...

[SFJCody]

Edwin, welcome to UMSF

Er, check the join date...

[Betelgeuze]

This is very exciting, hopefully the start of good things to come! Not that we have to complain about the exoplanet discoveries the last years, but still this is a big step and takes exoplanet-research to the next level.

Re the naming of names: I think keeping the current IAU convention would be fine for now. Once we can characterize these worlds would be the time for formal naming, IMHO, and surely SF provides a rich source.

One might ask, when do we know enough characteristics of a world to name it? There’s not a lot we know from most dwarf-planets, yet we named them. Also, we now have temperature maps, atmospheric data and even pictures of exoplanets, how much more do we have to know until we can name them?
Don’t get me wrong, I’m not saying we should name them yet, just asking what you think.

[centsworth_II]

Re: "Edwin, welcome to UMSF"

Er, check the join date...

Member No. 6! A more dedicated lurker I have not seen!

[Marz]

This visual discovery of a nearby planet sure whets the appetite for more! I can't wait for Terrestrial Planet Finder to get up and flying!

Being an armchair astronomer, I also like the idea of names, but I tend to think relevance/importance of the planet would eventually earn it a name. Placing arbitrary distance limits might be a problem if some really interesting planet is discovered that, for example, might become central to a new theory of solar system development. Rather than worry about what planets deserve a name, I'd rather see a naming system that hints at it's properties (analogous to the names of organic molecules, but with some leeway). So just rambling off the top of my head, maybe the 2nd syllable characterizes mass, and the last syllable characterizes temperature?

[nprev]

Re SF names: Yeah, it'll be decades IMHO before we can really tell enough about extrasolar planets to consider appropriate names from SF; it'll take instruments like TPF or better to do the job.

[Mongo]

I posted this some time ago someplace on this board, but cannot find the location right now. Fortunately, I had another copy I could cut and paste.

It's a shame that no logical exoplanetary nomenclature has been adopted. Instead the system used for multiple stellar systems is being used, which causes confusion (is HDxxxxxxb a planet or a star?) and includes only two pieces of information: primary and order of discovery.

I would have suggested something like the following:

STAR NAME Pxx (YEAR DISCOVERERS)

Where "P" indicates a planetary-mass object and "xx" indicates ten times the base ten logarithm the orbital period, in tenths of a day (to allow for sub-single-day orbital periods).

For example, the current nomenclature for the 55 Cnc system looks like this (ordered by increasing planetary orbital period):

55 Cnc e
55 Cnc b
55 Cnc c
55 Cnc f
55 Cnc d

Whereas the example nomenclature would look like this (also ordered by increasing orbital period):

55 Cnc P14 (2004 McArthur, Endl, Cochran, Benedict, Fischer, Marcy, Butler, Naef, Mayor, Queloz, Udry, Harrison)
55 Cnc P22 (1996 Butler, Marcy, Williams, Hauser, Shirts)
55 Cnc P26 (2002 Marcy, Butler, Fischer, Laughlin, Voght, Henry, Pourbaix)
55 Cnc P34 (2005 Wisdom)
55 Cnc P47 (2002 Marcy, Butler, Fischer, Laughlin, Voght, Henry, Pourbaix)

Giving four pieces of information: primary, orbital period, year of discovery and discovery team.

In my opinion, this is a much better choice of nomenclature than the current one, which apparently was simply continued unchanged from the stellar-mass system nomenclature.

Bill

[Hungry4info]

It's a shame that no logical exoplanetary nomenclature has been adopted.

False. Naming them in order of discovery is so far the only logical thing that has been thought up so far. Why? Because it's independent of knowledge of the planet. (i.e. orbital period, mass, etc).

Naming them in order of mass is illogical, as with the case of 55 Cnc, d would was discovered third, but is the most massive planet in the system. Naming planets in order of mass will cause one to have to rename planets. Very same goes for orbital period, etc.

Instead the system used for multiple stellar systems is being used, which causes confusion (is HDxxxxxxb a planet or a star?)

False. Star names are given capital letters, and planet names are given lower case letters.
HD xxxxxx B is the star.
HD xxxxxx Ab is the planet, orbiting the primary.
HD xxxxxx Bb is the planet, orbiting the secondary.

A possible source of confusion is for circumbinary planets, i.e., the planet at PSR B1620-26.

55 Cnc P14 (2004 McArthur, Endl, Cochran, Benedict, Fischer, Marcy, Butler, Naef, Mayor, Queloz, Udry, Harrison)
55 Cnc P22 (1996 Butler, Marcy, Williams, Hauser, Shirts)
55 Cnc P26 (2002 Marcy, Butler, Fischer, Laughlin, Voght, Henry, Pourbaix)
55 Cnc P34 (2005 Wisdom)
55 Cnc P47 (2002 Marcy, Butler, Fischer, Laughlin, Voght, Henry, Pourbaix)

That's rather hard to memorize. The current scheme works, it's easy to reference what planet one is talking to.

Furthermore, it's dependent on values of the orbit, in this case the orbital period. When a new planet is discovered in a solar system, this causes the orbital solution for the system to change. HD xxxxxx b has, say, a mass of 1.5 M_j and a period of 2.4 yr. HD xxxxxx c is discovered, and it turns out that b, with the new orbital solution to the radial velocity data, has a mass of 1.3 M_j and a period of 2.2 yr. Now we'll have to re-name the planet, if we used that scheme.
Here's an example using, again, 55 Cnc

Current orbital fit to 55 Cancri
55 Cnc b = 0.115 AU
55 Cnc c = 0.24 AU
55 Cnc d = 5.77 AU
55 Cnc e = 0.038 AU
55 Cnc f = 0.781 AU


From:
A Planet at 5 AU Around 55 Cancri
Geoffrey W. Marcy et al. 2002

55 Cnc b = 0.115 AU
55 Cnc c = 0.241 AU
55 Cnc d = 5.9 AU


You can see that the orbital solution to 55 Cnc d has changed since then, due to the effect of the newly discovered planet, 55 Cnc f, which affected the signal of d in the RV data.

Giving four pieces of information: primary, orbital period, year of discovery and discovery team.

One of which is subject to change as more knowledge is gathered, as previously shown, meaning that this scheme can not be used.

The naming scheme for planets is virtually the same as the one used for stars, just with lower-case letters. The star naming scheme has worked fine for many years, as has the planet-naming scheme.

That's my view on that.

[Mongo]

Wow. Are you always so confrontational in your posts?

I fail to see the problem with providing additional information in the official name of a planet. In current biological taxonomy, the year of description and name(s) of the describer are part of the official species (or higher taxon) name, and biologists seem to be fine with this -- for unofficial use they don't include the year and name information, but it is still part of the name for serious purposes. This planetary nomenclature was modeled in part on that system.

It is certainly true that published planetary periods occasionally change, but it would be easy to maintain an online list of planetary designations that have been changed. If an out-of-date designation is encountered, simply use it to look up the current designation. Problem solved.

[Hungry4info]

Wow. Are you always so confrontational in your posts?

Ah, I apologize. =(

I fail to see the problem with providing additional information in the official name of a planet. In current biological taxonomy, the year of description and name(s) of the describer are part of the official species (or higher taxon) name, and biologists seem to be fine with this. This planetary nomenclature was modeled in part on that system.

Yeah, there's nothing wrong with adding the discoverer's name, that is absolute and doesn't change.

It is certainly true that published planetary periods occasionally change, but it would be easy to maintain an online list of planetary designations that have been changed. If an out-of-date designation is encountered, simply use it to look up the current designation. Problem solved.

That is true. It still entails more work and effort than the current naming system though.

[Juramike]

Is there a (planned) system for naming the moons of exoplanets?

-Mike

[Hungry4info]

No.

[nprev]

Doesn't look like anything's been specifically defined, but if they follow Solar System conventions then they'll call extrasolar satellites by Roman numerals in order of discovery (ex. Upsilon Andromedae b-I for the first discovered natural satellite of that planet). Reference links:

http://planetarynames.wr.usgs.gov/append7.html
http://www.iau.org/public_press/themes/naming/

[djellison]

It seems nomenclature of planets outside our solar system is as prone to emotion as those within it.

Consider it on the banned subjects list as of now. Find another board to have semantic arguments on off-topic subjects.

[jamescanvin]

Another Exo-planet image!

Beta Pictoris

[nprev]

...slowly, the floodgates begin to open. The next few years should be purely fascinating!

[alan]

Beta Pictoris planet finally imaged?

A team of French astronomers using ESO's Very Large Telescope have discovered an object located very close to the star Beta Pictoris, and which apparently lies inside its disc. With a projected distance from the star of only 8 times the Earth-Sun distance, this object is most likely the giant planet suspected from the peculiar shape of the disc and the previously observed infall of comets onto the star. It would then be the first image of a planet that is as close to its host star as Saturn is to the Sun.

http://www.eso.org/public/outreach/press-r...8/pr-42-08.html

Edit: oops, didn't notice James posted same article

[Hungry4info]

Absolutely fascinating! Truly amazing!

[dilo]

Simply stunning sequence of news, guys. We are very lucky to live this epoch...

Beta Pictoris planet finally imaged?

I took the four images from original article:
http://www.eso.org/public/outreach/press-r...008/betapic.pdf
and I made a couple of elaborations in the right column, combining them in varius ways.

Attached thumbnail(s)

 

[ngunn]

When I looked on the Extrasolar Planets listing on Friday there were 10 directly imaged planets listed, so this is presumably number 11. All except the Hubble one are hot objects imaged by thermal infrared, and the Hubble planet is only 'visible' because it is surrounded by a debris disc thirty times the size and 4 or 5 magnitudes brighter than itself. I wholeheartedly agree that this is a wonderful time - the opening of a new window on our cosmic surroundings. We have great things to look forward to here, including the first reflected light image of a cold 'Jupiter' without a disc around it.

[Hungry4info]

We have great things to look forward to here, including the first reflected light image of a cold 'Jupiter' without a disc around it.

My bet is Eps Eri b.

[Decepticon]

Direct Image Of Extrasolar Planet

http://www.youtube.com/watch?v=aXKz4nxyPqw...feature=related

Does anyone have the full video to this link above!!!???

It gets cut off just as it gets better.

[ollopa]

Here's the full video:

http://files.filefront.com/Hub+SUBzip/;123...;/fileinfo.html

[Decepticon]

Thanks!

[Decepticon]

Has Fomalhaut had any wobbles detected?

[Hungry4info]

No. Fomalhaut b orbits the star every 870 or so years. It would take that long to observe one complete wobble from this planet.
Fomalhaut is also very bright, making it a difficult astrometry target, I would guess.

[dilo]

Fomalhaut is also very bright, making it a difficult astrometry target, I would guess.

Why? I think is exactly the opposite: higher the luminosity, better the S/N ratio for both astrometry and spectroscopy...

[Hungry4info]

Why? I think is exactly the opposite: higher the luminosity, better the S/N ratio for both astrometry and spectroscopy...

I'm unsure how the FGS works. Would Fomalhaut's brightness saturate the instrument?

[Del Palmer]

Yup. FGS normally observes mag +8 and fainter. You may observe brighter targets using a neutral density filter*, up to mag +3.


*Not recommended (complicates calibration).