A lower mass for the exoplanet WASP-21b

被引：19

作者：

Barros, S. C. C. ^{[1
]}

Pollacco, D. L. ^{[1
]}

Gibson, N. P. ^{[1
,2
]}

Howarth, I. D. ^{[3
]}

Keenan, F. P. ^{[1
]}

Simpson, E. K. ^{[1
]}

Skillen, I. ^{[4
]}

Steele, I. A. ^{[5
]}

机构：

[1] Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland

[2] Univ Oxford, Dept Phys, Oxford OX1 3RH, England

[3] UCL, Dept Phys & Astron, London WC1E 6BT, England

[4] Isaac Newton Grp Telescopes, E-38700 Tenerife, Spain

[5] Liverpool John Moores Univ, Astrophys Res Inst, Wirral CH61 4UA, Merseyside, England

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 2011年 / 416卷 / 04期

基金：

英国科学技术设施理事会;

关键词：

methods: data analysis; methods: observational; techniques: photometric; stars: individual: WASP-21; planetary systems; TRANSITING EXTRASOLAR PLANETS; PARAMETERS; RADII; PHOTOMETRY; STELLAR; CAMERA; STARS;

D O I：

10.1111/j.1365-2966.2011.19210.x

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present high-precision transit observations of the exoplanet WASP-21b, obtained with the Rapid Imager to Search for Exoplanets instrument mounted on the 2.0-m Liverpool Telescope. A transit model is fitted, coupled with a Markov chain Monte Carlo routine, to derive accurate system parameters. The two new high-precision transits allow us to estimate the stellar density directly from the light curve. Our analysis suggests that WASP-21 is evolving off the main sequence which led to a previous overestimation of the stellar density. Using isochrone interpolation, we find a stellar mass of 0.86 +/- 0.04 M-circle dot, which is significantly lower than previously reported (1.01 +/- 0.03 M-circle dot). Consequently, we find a lower planetary mass of 0.27 +/- 0.01 M-Jup. A lower inclination (87 degrees.4 +/- 0 degrees.3) is also found for the system than previously reported, resulting in a slightly larger stellar (R-* = 1.10 +/- 0.03 R-circle dot) and planetary radius (R-p = 1.14 +/- 0.04 R-Jup). The planet radius suggests a hydrogen/helium composition with no core which strengthens the correlation between planetary density and host star metallicity. A new ephemeris is determined for the system, i.e. T-0 = 245 5084.519 74 +/- 0.000 20 (HJD) and P = 4.322 5060 +/- 0.000 0031 d. We found no transit timing variations in WASP-21b.

引用

页码：2593 / 2599

页数：7

共 28 条

[1] WASP-40b: Independent Discovery of the 0.6 MJup Transiting Exoplanet HAT-P-27b [J].

Anderson, D. R. ;

Barros, S. C. C. ;

Boisse, I. ;

Bouchy, F. ;

Cameron, A. Collier ;

Faedi, F. ;

Hebrard, G. ;

Hellier, C. ;

Lendl, M. ;

Moutou, C. ;

Pollacco, D. ;

Santerne, A. ;

Smalley, B. ;

Smith, A. M. S. ;

Todd, I. ;

Triaud, A. H. M. J. ;

West, R. G. ;

Wheatley, P. J. ;

Bento, J. ;

Enoch, B. ;

Gillon, M. ;

Maxted, P. F. L. ;

McCormac, J. ;

Queloz, D. ;

Simpson, E. K. ;

Skillen, I. .

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 2011, 123 (903) :555-560

[2] WASP-21b: a hot-Saturn exoplanet transiting a thick disc star [J].

Bouchy, F. ;

Hebb, L. ;

Skillen, I. ;

Cameron, A. Collier ;

Smalley, B. ;

Udry, S. ;

Anderson, D. R. ;

Boisse, I. ;

Enoch, B. ;

Haswell, C. A. ;

Hebrard, G. ;

Hellier, C. ;

Joshi, Y. ;

Kane, S. R. ;

Maxted, P. F. L. ;

Mayor, M. ;

Moutou, C. ;

Pepe, F. ;

Pollacco, D. ;

Queloz, D. ;

Segransan, D. ;

Simpson, E. K. ;

Smith, A. M. S. ;

Stempels, H. C. ;

Street, R. ;

Triaud, A. H. M. J. ;

West, R. G. ;

Wheatley, P. J. .

ASTRONOMY & ASTROPHYSICS, 2010, 519

[3] Possible solutions to the radius anomalies of transiting giant planets [J].

Burrows, A. ;

Hubeny, I. ;

Budaj, J. ;

Hubbard, W. B. .

ASTROPHYSICAL JOURNAL, 2007, 661 (01) :502-514

[4] Efficient identification of exoplanetary transit candidates from SuperWASP light curves [J].

Cameron, A. Collier ;

Wilson, D. M. ;

West, R. G. ;

Hebb, L. ;

Wang, X-B. ;

Aigrain, S. ;

Bouchy, F. ;

Christian, D. J. ;

Clarkson, W. I. ;

Enoch, B. ;

Esposito, M. ;

Guenther, E. ;

Haswell, C. A. ;

Hebrard, G. ;

Hellier, C. ;

Horne, K. ;

Irwin, J. ;

Kane, S. R. ;

Loeillet, B. ;

Lister, T. A. ;

Maxted, P. ;

Mayor, M. ;

Moutou, C. ;

Parley, N. ;

Pollacco, D. ;

Pont, F. ;

Queloz, D. ;

Ryans, R. ;

Skillen, I. ;

Street, R. A. ;

Udry, S. ;

Wheatley, P. J. .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2007, 380 (03) :1230-1244

[5] PARAMETER ESTIMATION FROM TIME-SERIES DATA WITH CORRELATED ERRORS: A WAVELET-BASED METHOD AND ITS APPLICATION TO TRANSIT LIGHT CURVES [J].

Carter, Joshua A. ;

Winn, Joshua N. .

ASTROPHYSICAL JOURNAL, 2009, 704 (01) :51-67

[6] Y2 isochrones with an improved core overshoot treatment [J].

Demarque, P ;

Woo, JH ;

Kim, YC ;

Yi, SK .

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2004, 155 (02) :667-674

[7] ULTRACAM: an ultrafast, triple-beam CCD camera for high-speed astrophysics [J].

Dhillon, V. S. ;

Marsh, T. R. ;

Stevenson, M. J. ;

Atkinson, D. C. ;

Kerry, P. ;

Peacocke, P. T. ;

Vick, A. J. A. ;

Beard, S. M. ;

Ives, D. J. ;

Lunney, D. W. ;

McLay, S. A. ;

Tierney, C. J. ;

Kelly, J. ;

Littlefair, S. P. ;

Nicholson, R. ;

Pashley, R. ;

Harlaftis, E. T. ;

O'Brien, K. .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2007, 378 (03) :825-840

[8] An improved method for estimating the masses of stars with transiting planets [J].

Enoch, B. ;

Cameron, A. Collier ;

Parley, N. R. ;

Hebb, L. .

ASTRONOMY & ASTROPHYSICS, 2010, 516

[9] WASP-39b: a highly inflated Saturn-mass planet orbiting a late G-type star [J].

Faedi, F. ;

Barros, S. C. C. ;

Anderson, D. R. ;

Brown, D. J. A. ;

Cameron, A. Collier ;

Pollacco, D. ;

Boisse, I. ;

Hebrard, G. ;

Lendl, M. ;

Lister, T. A. ;

Smalley, B. ;

Street, R. A. ;

Triaud, A. H. M. J. ;

Bento, J. ;

Bouchy, F. ;

Butters, O. W. ;

Enoch, B. ;

Haswell, C. A. ;

Hellier, C. ;

Keenan, F. P. ;

Miller, G. R. M. ;

Moulds, V. ;

Moutou, C. ;

Norton, A. J. ;

Queloz, D. ;

Santerne, A. ;

Simpson, E. K. ;

Skillen, I. ;

Smith, A. M. S. ;

Udry, S. ;

Watson, C. A. ;

West, R. G. ;

Wheatley, P. J. .

ASTRONOMY & ASTROPHYSICS, 2011, 531

[10] Planetary radii across five orders of magnitude in mass and stellar insolation: Application to transits [J].

Fortney, J. J. ;

Marley, M. S. ;

Barnes, J. W. .

ASTROPHYSICAL JOURNAL, 2007, 659 (02) :1661-1672

← 1 2 3 →