SuperWASP Results

WASP 10b paper is out.

WASP-10b: a 3M_J, eccentric transiting gas-giant planet
http://arxiv.org/abs/0806.1482

Abstract wrote:

We report the discovery of WASP-10b, a new transiting extrasolar planet (ESP) discovered by the WASP Consortium and confirmed using NOT FIES and SOPHIE radial velocity data. A 3.09 day period, 33 mmag transit depth, and 2.36 hour duration are derived for WASP-10b using WASP and high precision photometric observations. Simultaneous fitting to the photometric and radial velocity data using a Markov-chain Monte Carlo procedure leads to a planet radius of 1.29R_J, a mass of 3.06M_J and eccentricity of $\approx$0.06. WASP-10b is one of the more massive transiting ESPs, and we compare its characteristics to the current sample of transiting ESP, where there is currently little information for masses greater than ~2M_J and non-zero eccentricities. WASP-10's host star, GSC 2752-00114 (USNO-B1.0 1214-0586164) is among the fainter stars in the WASP sample, with V=12.7 and a spectral type of K5. This result shows promise for future late-type dwarf star surveys.

And of course, WASP-14 b paper.

WASP-14b: A 7.7 Mjup transiting exoplanet in an eccentric orbit
http://arxiv.org/abs/0806.1478

Abstract wrote:

We report the discovery of a 7.7 Mjup exoplanet WASP-14b, one of the most massive transiting exoplanets observed to date. The planet orbits the tenth-magnitude F5V star USNO-B1 11118-0262485 with a period of 2.243756 days and orbital eccentricity e = 0.095. A simultaneous fit of the transit light curve and radial velocity measurements yields a planetary mass of 7.7(+0.4)(-0.7) Mjup and a radius of 1.26(+0.08 ) (-0.06) Rjup. This leads to a mean density of about 5.1 gcm^{-3} making it one of the densest transiting exoplanets yet found at an orbital period less than 3 days. We estimate this system to be at a distance of 160+/-20 pc. Spectral analysis of the host star reveals a temperature of 6475+/-100 K, log g = 4.33 cms$^{-2}$ and v sin i = 4.9+/-1.0 km s$^{-1}$, and also a high lithium abundance, log N(Li) = 2.84+/-0.05. The stellar density, effective temperature and rotation rate suggest an age for the system of about 0.5--1.0 Gyr.

Interesting to have even the eccentricity of such "roasters". Moreover Wasp-10 turns out almost nearby (90 pc).

Note that the paper for WASP-10 mentions the existence of 17 WASP planets, which is two more than are currently displayed on the SuperWASP planets page.

So... WASP-16 and WASP-17...

To come soon? Meanwhile I wait the Nantes conference of June 16-18. Hot Earths upcoming....

On the arXiv... HAT-P-10b: A light and moderately hot Jupiter transiting a K dwarf

in which they note:

Quote :

We note that a similar object has been announced by the SuperWASP team (WASP-11b), but details (such as identification) are unavailable as yet.

A preprint appeared on Extrasolar Planets Encyclopaedia... The sub-Jupiter mass transiting exoplanet WASP-11b (pdf)

The two objects are the same (parent star 2MASS 03092855+3040249).

Insert comment about the length of time between doing the press release and being ready to write the paper...

I'll admit to be moderately annoyed...

Wonder which one of the two entries EPE is going to delete...

Lazarus wrote:

Wonder which one of the two entries EPE is going to delete...

I'm surprised Schneider hasn't already deleted one. He's certainly aware that HAT-P-10 b = WASP-11 b, as is stated on the HAT-P-10 b page. Perhaps he could merge the two, and add as a note the HATnet solution.

Now a combined designation for the star: WASP-11/HAT-P-10

I am unclear whether the planet designation would be WASP-11b/HAT-P-10b or WASP-11/HAT-P-10 b, though the front page of EPE seems to indicate the former.

Fixed. 313. Alike Donald Duck's car.

However it's quite an old star with 11.2 gigayerars age.

Yeah that's a big one... and the period is short, too. P=1.09 d.
WASP-12 paper.

Abstract wrote:

We report on the discovery of WASP-12b, a new transiting extrasolar planet with R_pl=1.83^+0.09_-0.11 R_J and M_pl=1.45^+0.07_-0.15 M_J. The planet and host star properties were derived from a Monte Carlo Markov Chain analysis of the transit photometry and radial velocity data. Furthermore, by comparing the stellar spectrum with theoretical spectra and stellar evolution models, we determined that the host star is a super-solar metallicity ([M/H]=0.3^+0.05_-0.15), late-F (T_eff}=6300⁺²⁰⁰_-100~K) star which is evolving off the zero age main sequence. The planet has an equilibrium temperature of T_eq =2525~K caused by its very short period orbit (P=1.09~days) around the hot, 12th magnitude host star. WASP-12b has the largest radius of any transiting planet yet detected. It is also the most heavily irradiated and the shortest period planet in the literature.

Quick question just to make sure we don't run afoul of anything... has this presentation began yet? Note the embargo...

Yes indeed. It presented at 3:00 EST today.

Ok cool, thought so but just wanted to make sure.

Lazarus wrote:

Ok cool, thought so but just wanted to make sure.

Quite understandable!

I found this bit of interesting news on the Universe Today blog.

UniverseToday wrote:

Now, SuperWASP researchers hope to probe the planetary system for UV light radiating from the exoplanet, possibly showing evidence that WASP-12b's atmosphere is undergoing aggressive stripping or evaporation at such close proximity to the host star.

http://space.newscientist.com/article/dn14943-starhugging-planet-is-hottest-and-fastest-found.html
Made it sound like that a metal-poor gas giant will not heat up as much as a metal-rich gas giant. Starting to sound like a star...

marasama wrote:

http://space.newscientist.com/article/dn14943-starhugging-planet-is-hottest-and-fastest-found.html
Made it sound like that a metal-poor gas giant will not heat up as much as a metal-rich gas giant. Starting to sound like a star...

If I may ask, for clarity, what do you mean by this?

I just meant that the metal-poor and metal-rich is usually stuff that is referred to Stars and Brown Dwarfs.

As for the Gas Giants, it is speculating that if the core or overall composition of the Gas Giant is metal-rich (compared to? don't know what they are comparing with), then the Gas Giant seems to hold more heat.

A Smaller Radius for the Transiting Exoplanet WASP-10b
http://arxiv.org/abs/0812.0029

Abstract wrote:

We present photometry of WASP-10 during the transit of its short-period Jovian planet. We employed the novel PSF-shaping capabilities the OPTIC camera mounted on the UH 2.2m telescope to achieve a photometric precision of 4.7e-4 per 1.3 min sample. With this new light curve, in conjunction with stellar evolutionary models, we improve on existing measurements of the planetary, stellar and orbital parameters. We find a stellar radius Rstar = 0.698 +/- 0.012 Rsun and a planetary radius Rp = 1.080 +/- 0.020 Rjup. The quoted errors do not include any possible systematic errors in the stellar evolutionary models. Our measurement improves the precision of the planet's radius by a factor of 4, and revises the previous estimate downward by 16% (2.5sigma, where sigma is the quadrature sum of the respective confidence limits). Our measured radius of WASP-10b is consistent with previously published theoretical radii for irradiated Jovian planets.

Improved parameters for the transiting hot Jupiters WASP-4b and WASP-5b
http://arxiv.org/abs/0812.1998

Abstract wrote:

The gaseous giant planets WASP-4b and WASP-5b are transiting 12 magnitude solar-type stars in the Southern hemisphere. The aim of the present work is to refine the parameters of these systems using high cadence VLT/FORS2 z-band transit photometry and high resolution VLT/UVES spectroscopy. For WASP-4, the new estimates for the planet radius and mass from a combined analysis of our VLT data with previously published transit photometry and radial velocities are R_p = 1.30 +0.05-0.04 R_jup and M_p = 1.21 +0.13-0.08 M_jup, resulting in a density rho_p = 0.55 +0.04-0.02 rho_jup. The radius and mass for the host star are R_s = 0.87 +0.04-0.03 R_sun and M_s = 0.85 +0.11-0.07 M_sun. Our ground-based photometry reaches 550 ppm at time sampling of ~50 seconds. Nevertheless, we also report the presence of an instrumental effect on the VLT that degraded our photometry for the WASP-5 observations. This effect could be a major problem for similar programs. Our new estimates for the parameters of the WASP-5 system are R_p = 1.09 +-0.07 R_jup, M_p = 1.58 +0.13-0.10 M_jup, rho_p = 1.23 +0.26-0.16 rho_jup, R_s = 1.03 +0.06-0.07 R_sun, and M_s = 0.96 +0.13-0.09 M_sun. The measured size of WASP-5b agrees well with the basic models of irradiated planets, while WASP-4b is clearly an `anomalously' large planet.

The WASP-12 paper is out.

WASP-12b: The hottest transiting planet yet discovered
http://arxiv.org/abs/0812.3240

Abstract wrote:

We report on the discovery of WASP-12b, a new transiting extrasolar planet with $R_{\rm pl}=1.79 \pm 0.09 R_J$ and $M_{\rm pl}=1.41 \pm 0.1 M_J$. The planet and host star properties were derived from a Monte Carlo Markov Chain analysis of the transit photometry and radial velocity data. Furthermore, by comparing the stellar spectrum with theoretical spectra and stellar evolution models, we determined that the host star is a super-solar metallicity ([M/H]$=0.3^{+0.05}_{-0.15}$), late-F (T$_{\rm eff}=6300^{+200}_{-100}$ K) star which is evolving off the zero age main sequence. The planet has an equilibrium temperature of T$_{\rm eq}$=2516 K caused by its very short period orbit ($P=1.09$ days) around the hot, 12th magnitude host star. WASP-12b has the largest radius of any transiting planet yet detected. It is also the most heavily irradiated and the shortest period planet in the literature.

I've merged the WASP threads for the sake of organisation.

1.79 Jupiter radii. It turns out being the largest exoplanet detected so far. TrES-4b just bites the dust
BAAS (Abstracts online) gives even a radius of 1.83 Rj.

Though I use to not trust BAAS.

WASP-12 ephemeris has been corrected thanks to amateur observations - see here

Probably useful to have a quick summary of what has and hasn't been published from the April 1st set of SuperWASP planets.

WASP-6b	arXiv
WASP-7b	Published January 2009
WASP-8b	Not yet identified
WASP-9b	Not yet identified
WASP-10b	Published December 2008
WASP-11b	arXiv; =HAT-P-10b
WASP-12b	arXiv
WASP-13b	Not yet identified
WASP-14b	Published December 2008
WASP-15b	arXiv