Talk:WASP-17b

Density and size
I thought it was least dense, as opposed to largest? Evercat (talk) 10:41, 13 August 2009 (UTC)
 * From one of the articles;
 * WASP-17b is also a contender for the largest exoplanet ever found. It is about half the mass of Jupiter but up to twice its width, possibly de-throning the previous largest-known exoplanet. It's about as dense as polystyrene, and if you could place it in a bathtub, it would bob like a beach ball. It is only 7 million kilometres away from its star – eight times as close as Mercury is to the sun, and orbits once every 3.7 days.

Master of Puppets - Call me MoP! :D  10:44, 13 August 2009 (UTC)

Radius
can u guys please put Template:Planetary radius on the page to see how large the planet is?????!!!!!69.227.71.74 (talk) 00:50, 14 August 2009 (UTC)

Atmosphere
The article by D. R. Anderson et al says "its atmospheric opacity is expected to be high due, for example, to the presence of TiO and VO gases". Does this refer to titanium oxide and vanadium oxide? Gary (talk) 01:11, 14 August 2009 (UTC)

New Infobox
The new infobox has a lot of information but it doesn't say where that information came from. Also, the radius is much more precise than the old infobox's radius, which had a citation - an article that's only two days old! The information about the density was previously a range (0.06–0.14 times the density of Jupiter), but given the radius of 1.74 RJ, we should be able to easily calculate a more precise density, and we should be able to settle the question whether this is the largest known exoplanet. Why is this information so precise, and where does it come from? Gary (talk) 02:28, 14 August 2009 (UTC)
 * Now I see this source: which gives the radius as 1.74, but that page in turn has a link to the article that says the radius is 1.5-2 Jupiter radii. This looks like there's an error somewhere.  —Preceding unsigned comment added by Gary2863 (talk • contribs) 02:32, 14 August 2009 (UTC)

all but one (perhaps 2 or 3 by now) exoplanets so far discovered have radi greater then jupiters. i don't think an estimated 1.7 times jupiter would make it the biggest known exoplanet with a degree of certainty. actually you may not even want to call it a planet, mayb it is not, since the definition of planet involves the body's own gravity be functional relative to its sun..if it is a captured body that is not what happened.24.132.171.225 (talk) 13:16, 14 August 2009 (UTC)

The infobox(s) should also be checked against the entire paper (in PDF) for discrepancies. (Also please see my note on the talk page of retrograde and direct motion.) --RoyGoldsmith (talk) 13:19, 14 August 2009 (UTC)


 * I agree the data should be checked and uncertainty error ranges need to be included. I added ranges for radius from the original paper because three solution cases were presented. I skimmed the other values (mass solutions for example look tighter as 0.49 +0.059-0.056, and 0.496 +0.064-0.060 and 0.498 +0.059-0.056), but eccentricity is quite uncertain in the paper. I'll leave the rest for someone else. 84user (talk) 18:28, 14 August 2009 (UTC)


 * It seems all very complicated, really. It's worth noting that the three cases given in the paper are not equivalent - each of them have different implied assumptions going into the calculation. I think Case 1 is probably the most reasonable, because cases 2 and 3 make a number of stronger assumptions. As far as I can tell, Case 2 assumes the star is like a normal star, and so estimates values using the expected average from a star of the same type. Whilst case 3 assumes the planet's orbit is circular - which I think is probably a dangerous assumption to make, because how can eccentricity be 'insignificant' when it makes a big difference to estimated values? (It should not surprise us that these assumption based estimates quote smaller ranges of values - because some of the numbers were just plugged in. This does not necessarily mean they are more accurate!)
 * Similar, however, it would not surprise me if strong assumptions were also made in the estimation of properties of TrES-4 - and I don't know if the influence of these assumptions were included the error margins given. (Someone should read the references there and figure this out? I don't really understand them.)
 * So, my suggestions: probably we should base things on case 1, and footnote the other two cases. We shouldn't try to make too bold a pronouncement on which planet is the least dense. We shouldn't really use too much sig figs in giving properties, because that could be misleading. And well, maybe someone should email the authors of the paper and ask them for their perspective.--Fangz (talk) 11:29, 19 August 2009 (UTC)
 * I think there are problems with the way the infobox is set up to begin with. Is there anywhere I could go to discuss things like the way citations can't be added without getting in the way of units? Gary (talk) 14:11, 19 August 2009 (UTC)
 * Yeah, infoboxes are set up as though there is never any ambiguity, uncertainty or disagreement about the items in them. I think that is a disservice to readers, even if the problems are addressed in the text. We could start a discussion at the village pump. -- Donald Albury 14:48, 19 August 2009 (UTC)
 * I have posted this problem to the Village Pump here. --Gary (talk) 21:53, 19 August 2009 (UTC)
 * They told me to ask about it here, so I did. Gary (talk) 07:35, 20 August 2009 (UTC)

transit
There is a "transit" entry in the infobox. Does this refer to a specific time, using a Julian date, at which the planet transited its star? If so, why is there only one date? There appear to be at least 13 recorded transits recorded here, if I'm reading this right.Gary (talk) 19:01, 14 August 2009 (UTC)
 * It's part of the orbital elements. So, it should be the result of fitting an orbit to the observed transit times.  This will yield a calculated transit time, an orbital period, and so on. Spacepotato (talk) 15:47, 20 August 2009 (UTC)