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TOPIC: WASP-10b extrasolar planet


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WASP-10 b
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Title: Analysis of new high-precision transit light curves of WASP-10 b: starspot occultations, small planetary radius, and high metallicity
Authors: G. Maciejewski, St. Raetz, N. Nettelmann, M. Seeliger, Ch. Adam, G. Nowak, R. Neuhaeuser

The WASP-10 planetary system is intriguing because different values of radius have been reported for its transiting exoplanet. The host star exhibits activity in terms of photometric variability, which is caused by the rotational modulation of the spots. Moreover, a periodic modulation has been discovered in transit timing of WASP-10 b, which could be a sign of an additional body perturbing the orbital motion of the transiting planet. We attempt to refine the physical parameters of the system, in particular the planetary radius, which is crucial for studying the internal structure of the transiting planet. We also determine new mid-transit times to confirm or refute observed anomalies in transit timing. We acquired high-precision light curves for four transits of WASP-10 b in 2010. Assuming various limb-darkening laws, we generated best-fit models and redetermined parameters of the system. The prayer-bead method and Monte Carlo simulations were used to derive error estimates. Three transit light curves exhibit signatures of the occultations of dark spots by the planet during its passage across the stellar disk. The influence of stellar activity on transit depth is taken into account while determining system parameters. The radius of WASP-10 b is found to be no greater than 1.03 Jupiter radii, a value significantly smaller than most previous studies indicate. We calculate interior structure models of the planet, assuming a two-layer structure with one homogeneous envelope atop a rock core. The high value of the WASP-10 b's mean density allows one to consider the planet's internal structure including 270 to 450 Earth masses of heavy elements. Our new mid-transit times confirm that transit timing cannot be explained by a constant period if all literature data points are considered. They are consistent with the ephemeris assuming a periodic variation of transit timing...

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RE: WASP-10b extrasolar planet
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Title: Transit Observations of the WASP-10 System
Authors: Jason A Dittmann, Laird M Close, Louis J Scuderi, Marita D Morris

We present here observations of the transit of WASP-10b on 14 October 2009 UT taken from the University of Arizona's 1.55 meter Kuiper telescope on Mt. Bigelow. Conditions were photometric and accuracies of 2.0 mmag RMS were obtained throughout the transit. We have found that the ratio of the planet to host star radii is in agreement with the measurements of Christian et al. (2008) instead of the refinements of Johnson et al. (2009), suggesting that WASP-10b is indeed inflated beyond what is expected from theoretical modelling. We find no evidence for large (> 20 s) transit timing variations in WASP-10b's orbit from the ephemeris of Christian et al. (2008) and Johnson et al. (2009).

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Nearly a decade after astronomers first detected an extrasolar gas giant moving across the face of its parent star, a team of astronomers report that a new camera is giving them the sensitivity they need to spot planets nearly as small as Earth.
The team observed a planet - WASP-10b - around three times the mass of Jupiter orbiting the star WASP-10, about 300 light years from Earth and measured precisely how much the star dimmed as the planet passed in front of it.

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One of the densest planets found  
Astronomers have used an ultra sensitive camera to measure the precise size of a planet around a distant star, and determine that it is one of the most densest planets in the known Universe.
The team studied a planet called WASP-10b, which was thought to have an unusually large diameter.
They were able to measure its diameter with much higher precision than before, leading to the finding that it is one of the densest planets known, rather than one of the most bloated.

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Exoplanet WASP-10b
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A team of astronomers led by John Johnson of the University of Hawaii's Institute for Astronomy has used a new technique to measure the precise size of a planet around a distant star. They used a camera so sensitive that it could detect the passage of a moth in front of a lit window from a distance of 1,000 miles.
The camera, mounted on the UH 2.2-meter telescope on Mauna Kea, measures the small decrease in brightness that occurs when a planet passes in front of its star along the line-of-sight from Earth. These "planet transits" allow researchers to measure the diameters of worlds outside our solar system.

Source: University of Hawaii

-- Edited by Blobrana at 18:46, 2008-12-11

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RE: WASP-10b extrasolar planet
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Title: A Smaller Radius for the Transiting Exoplanet WASP-10b
Authors: John A. Johnson, Joshua N. Winn, Nicole E. Cabrera, Joshua A. Carter

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.

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Title: WASP-10b: a 3M_J, eccentric transiting gas-giant planet
Authors: D.J. Christian, N.P. Gibson, E.K. Simpson, R.A. Street, I. Skillen, D. Pollacco, A. Collier Cameron, H.C. Stempels, C.A. Haswell, K. Horne, Y.C. Joshi, F.P. Keenan, D.R. Anderson, S. Bentley, F. Bouchy, W.I. Clarkson, B. Enoch, L. Hebb, G. Hébrard, C. Hellier, J. Irwin, S.R. Kane, T.A. Lister, B. Loeillet, P. Maxted, M. Mayor, I. McDonald, C. Moutou, A.J. Norton, N. Parley, F. Pont, D. Queloz, R. Ryans, B. Smalley, A.M.S. Smith, I. Todd, S. Udry, R.G. West, P.J. Wheatley, D.M. Wilson

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.

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