SuperWASP Results

An interesting discovery, easy for the WASP team to number their exo-discoveries but difficult for those who want to memorize around which stars the exo-planets orbit

Recommendation: the BBC "Open University" DVD entitled "The Cosmos: a beginner's Guide" has superb images of the WASP-North hardware at LaPalma - Canary Islands.

An interesting paper going deep into the process of confirming WASP candidates. It overviews some example WASP planets, as well as presents a few nameless candidates. It's a fairly old paper (pre WASP-6), WASP-17 is recognizable in the un-named candidates. It seems they also have a possible two-planet system for which they are gathering more data.

http://www.astro.keele.ac.uk/~dw/files/thesis_pdf_version.pdf

I could even find which are the target stars according SWASP classification available in SIMBAD.
Especially I would have known which host star is that nearby M5 dwarf mentioned in the paper, inferred to host a low-mass transiting exoplanet..
But I would not make any kind of embargo breach.

News story about WASP-18b at space.com - the planet has an orbital period less than one day.

Looks like it's going to be a Nature paper. Hmmmm.

From SIMBAD, here's the identity of the star WASP-18... it's a Hipparcos star, which is nice.

Lazarus wrote:

From SIMBAD, here's the identity of the star WASP-18... it's a Hipparcos star, which is nice.

It's also the brightest planet WASP planet-host. Even has an HD number.

Edit: On this page, http://astroblogger.blogspot.com/ , there's information on WASP-18, including a nice .ssc for Celestia


( go ahead and just delete the relevant info if it's any sort of embargo breach... though with the paper published, I don't see how it would be )

Yes... note that while the paper is not free access, the tables are... so the orbital elements are available for all to see.

Note also that the Celestia file provided there is incorrect as the orbital elements have not been translated into ecliptic coordinates.

Greg Laughlin writes that F-type stars may be inefficient at dissipating tidal energy, and may allow planets like WASP-18 b and OGLE-TR-56 b to remain in such close orbits for longer periods of time than usual.

Quote :

Darin Ragozzine pointed me to to a recent article by Barker and Ogilvie that indicates that WASP-18 may indeed be very poor at dissipating tidal energy. It’s an F-type star, somewhat more massive than the sun, with a negligible convective envelope, and no good recourse to turning tidal waves into heat. It’s like a bell that can ring and ring without making a sound. According to Barker and Ogilvie, similarly inviscid F-type parent stars are also responsible for the survival of WASP-12 and OGLE-TR-56b. Their prediction for WASP-18b would be that changes in the orbital period will not be observable, even with the excellent precision that will be obtained by timing the orbit over periods of a decade or more.

Furthermore, a transit was found in Hipparcos data, but the error bars are significant, and the accuracy is too poor to constrain the orbital period any further.

Sadly we lose one WASP planet:

http://exoplanet.eu/star.php?st=WASP-9

Retracted.

I don't understand how a transiting hot Jupiter can be retracted, being detected with both RV and transit. Remember this was claimed about Lupus-TR-3b as well, but it was later shown that the planet was indeed not unconfirmed. The uncertainty does explain why further information on this planet has been lacking.

And of considerably more importance, does the next planet from WASP get to fill in the gap between 8 and 10?

Was wondering what the delay was for WASP-8b and WASP-9b... leads to the question of whether WASP-8b is also a false positive.

I doubt the designation will get filled in, WASP-9 presumably still refers to the multi-star system. Hopefully there will be a paper about this: as is noted, this is an extremely subtle false positive, so more information would be very useful to avoid being surprised by this in the future.

Quote :

Detailed analysis of spectroscopic observations made with HARPS to observe the Rossiter-McLaughlin effect have revealed the presence of a faint, strongly-broadened stellar spectrum underlying the narrower profile of the host star. The broad spectrum shows orbital motion on a 0.66667-day period and the spectroscopic signature of a transit by a fainter stellar companion. The object thus appears to be a hierarchical stellar multiple; the transits are diluted eclipses of the fainter stellar binary.

As astrophysical false positives go, this one was very, very subtle. The transit depths showed no obvious dependence on wavelength. Combined photometric and RV models yielded sensible solutions. There was no strong evidence of correlated line-bisector and velocity variation, presumably due to the extreme rotational broadening of the background binary spectrum.

Usual not-viewable BAAS

Quote :

FLEMING S., GE J., MAHADEVAN S. et al. (36 additional authors) , 2009 (update : 23 November 2009) Binary Science from the MARVELS Pilot Project: Detection of a Candidate Substellar Companion and Identification of Eclipsing Binaries with Archival SuperWASP Data BAAS , 42, no 1 , 472.03 abstract

Quote :

MA B., GE J., NIEDZIELSKI A., WOLSZCSAN A., LEE B., MAHADEVAN S., FLEMING S., SCHNEIDER D., JIANG P., MAZEH T. & ZUCKER S. , 2009 (update : 21 November 2009) Two Dimensional Cross-correlation Analysis of a Bearing Low Mass Companion Close Binary System Found by the SDSS/MARVELS Pilot Survey BAAS , 42, no 1 , 472.02 abstract

If someone is able to display the page, please copy and paste in quote form what's typed there.

Accessing abstractsonline is complicated by the need to go in through the main page for the conference in question. Direct links do not work. Remember that results are embargoed until time of presentation.

Maybe. Did you find a link to this page elsewhere? or is the information hidden?

I strongly encourage re-reading the embargo policy.

Quote :

Bad sources of information:
...
· Any other online material that is hidden.

Agree, I delete.

WASP-19 b officially announced

http://exoplanet.eu/star.php?st=WASP-19

Yay! Remarkably short orbital period. =o

Interesting bit of the abstract.

Quote :

In addition, we detect periodic, sinusoidal flux variations in the
light curve which are used to derive a rotation period for the star of P
_rot
= 10.5 ± 0.2 days. The relatively short stellar rotation period
suggests that either WASP-19 is somewhat young (~ 600 Myr old) or tidal
interactions between the two bodies have caused the planet to spiral
inward over its lifetime resulting in the spin-up of the star. Due to
the detection of the rotation period, this system has the potential to
place strong constraints on the stellar tidal quality factor, Q'
_s
, if a more precise age is determined.

I would say I was knowing about its existence much time before, but... well, forget it...

Take a look also here

http://en.wikipedia.org/wiki/WASP-19

Great work Edasich! Have you considered updating the table of WASP planets at the SuperWASP page? The table is a little bit out of date, and doesn't include the retraction of WASP-8 b.

WASP-8 b? Wasn't WASP-9?

Yes, if I could, I would do that

Lazybone researchers of SuperWASP!!

Yeah, my bad. WASP-9. I just woke up.

WASP-19 b is now on ArXiv

WASP-19b: the shortest period transiting exoplanet yet discovered
http://arxiv.org/abs/1001.0403

Abstract wrote:

We report on the discovery of a new extremely short period transiting extrasolar planet, WASP-19b. The planet has mass Mpl = 1.15 \pm 0.08 MJ, radius Rpl = 1.31 \pm 0.06 RJ, and orbital period P = 0.7888399 \pm 0.0000008 days. Through spectroscopic analysis, we determine the host star to be a slightly super-solar metallicity ([M/H] = 0.1 \pm 0.1 dex) G-dwarf with Teff = 5500 \pm 100 K. In addition, we detect periodic, sinusoidal flux variations in the light curve which are used to derive a rotation period for the star of Prot = 10.5 \pm 0.2 days. The relatively short stellar rotation period suggests that either WASP-19 is somewhat young (~ 600 Myr old) or tidal interactions between the two bodies have caused the planet to spiral inward over its lifetime resulting in the spin-up of the star. Due to the detection of the rotation period, this system has the potential to place strong constraints on the stellar tidal quality factor, Q's, if a more precise age is determined.