* Astronomy

Members Login
Post Info TOPIC: WASP-26b


L

Posts: 131433
Date:
RE: WASP-26b
Permalink  
 


Title: Warm Spitzer Occultation Photometry of WASP-26b at 3.6m and 4.5m
Authors: D.P. Mahtani P.F.L. Maxted, D.R. Anderson, A.M.S. Smith, B. Smalley, J. Tregloan-Reed, J. Southworth, N. Madhusudhan, A. Collier Cameron, M. Gillon, J. Harrington, C. Hellier, D. Pollacco, D. Queloz, A.H.M.J. Triaud, R.G. West

We present new warm Spitzer occultation photometry of WASP-26 at 3.6m and 4.5m along with new transit photometry taken in the g,r and i bands. We report the first detection of the occultation of WASP-26b, with occultation depths at 3.6m and 4.5m of 0.00126 0.00013 and 0.00149 0.00016 corresponding to brightness temperatures of 1825 80K and 1725 89K, respectively. We find that the eccentricity of the orbit is consistent with a circular orbit at the 1 sigma level with a 3 sigma upper limit of e < 0.04). According to the activity-inversion relation of Knutson et al. (2010), WASP-26b is predicted to host a thermal inversion. The brightness temperatures deduced from the eclipse depths are consistent with an isothermal atmosphere, although it is within the uncertainties that the planet may host a weak thermal inversion. The data are equally well fit by atmospheric models with or without a thermal inversion. We find that variation in activity of solar-like stars does not change enough over the time-scales of months or years to change the interpretation of the Knutson et al. (2010) activity-inversion relation, provided that the measured activity level is averaged over several nights. Further data are required to fully constrain the thermal structure of the atmosphere because the planet lies very close to the boundary between atmospheres with and without a thermal inversion.

Read more (1833kb, PDF)



__________________


L

Posts: 131433
Date:
Permalink  
 

Title: WASP-26b: A 1-Jupiter-mass planet around an early-G-type star
Authors: B. Smalley (Keele University), D.R. Anderson, A. Collier Cameron, M. Gillon, C. Hellier, T.A. Lister, P.F.L. Maxted, D. Queloz, A.H.M.J. Triaud, R.G. West, S.J. Bentley, B. Enoch, F. Pepe, D.L. Pollacco, D. Segransan, A.M.S. Smith, J. Southworth, S. Udry, P.J. Wheatley, P.L. Wood, J. Bento

We report the discovery of WASP-26b, a moderately over-sized Jupiter-mass exoplanet transiting its 11.3-magnitude early-G-type host star (1SWASP J001824.70-151602.3; TYC 5839-876-1) every 2.7566 days. A simultaneous fit to transit photometry and radial-velocity measurements yields a planetary mass of 1.02 0.03 M_Jup and radius of 1.32 0.08 R_Jup. The host star, WASP-26, has a mass of 1.12 0.03 M_sun and a radius of 1.34 0.06 R_sun and is in a visual double with a fainter K-type star. The two stars are at least a common-proper motion pair with a common distance of around 250 15 pc and an age of 6 2 Gy.

Read more (1401kb, PDF)

__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard