Search Results - "Howarth, Ian D."

A reappraisal of parameters for the putative planet PTFO 8-8695b and its potentially precessing parent star by Howarth, Ian D.

“…Published photometry of fading events in the PTFO8-8695 system is modelled using improved treatments of stellar geometry, surface intensities, and,…”
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ϵ Sagittarii: An Extreme Rapid Rotator with a Decretion Disk by Bailey, Jeremy, Lewis, Fiona, Howarth, Ian D., Cotton, Daniel V., Marshall, Jonathan P., Kedziora-Chudczer, Lucyna

“…Abstract We report high-precision, multiwavelength linear-polarization observations of the bright B9 (or A0) star ϵ Sagittarii. The polarization shows the…”
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On stellar limb darkening and exoplanetary transits by Howarth, Ian D.

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Kinematics of massive stars in the Small Magellanic Cloud by Evans, Christopher J., Howarth, Ian D.

“…We present radial velocities for 2045 stars in the Small Magellanic Cloud (SMC), obtained from the 2dF survey by Evans et al. The great majority of these stars…”
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New limb-darkening coefficients and synthetic photometry for model-atmosphere grids at Galactic, LMC and SMC abundances by Howarth, Ian D.

“…New grids of atlas9 models have been calculated using revised convection parameters and updated opacity-distribution functions (ODFs), for chemical…”
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On stellar limb darkening and exoplanetary transits by Howarth, Ian D.

“…This paper examines how to compare stellar limb-darkening coefficients evaluated from model atmospheres with those derived from photometry. Different…”
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Towards an understanding of the Of ? p star HD 191612: optical spectroscopy by Howarth, Ian D, Walborn, Nolan R, Lennon, Danny J, Puls, Joachim, Nazé, Yaël, Annuk, K, Antokhin, I, Bohlender, D, Bond, H, Donati, J. F, Georgiev, L, Gies, D, Harmer, D, Herrero, A, Kolka, I, McDavid, D, Morel, Thierry, Negueruela, I, Rauw, Grégor, Reig, P

“…We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe–O8fp). The Balmer and He i lines show strongly variable emission…”
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A study of the rapid rotator ζ Aql: differential surface rotation? by Howarth, Ian D, Bailey, Jeremy, Cotton, Daniel V, Kedziora-Chudczer, Lucyna

“…ABSTRACT We report new, extremely precise photopolarimetry of the rapidly-rotating A0 main-sequence star ζ Aql, covering the wavelength range ∼400–900 nm,…”
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Are the O stars in WR+O binaries exceptionally rapid rotators? by Reeve, Dominic, Howarth, Ian D

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The distance, rotation, and physical parameters of ζ Pup by Howarth, Ian D, van Leeuwen, Floor

“…ABSTRACT We scrutinize the Hipparcos parallax for the bright O supergiant ζ Pup and confirm that the implied distance of 332 ± 11 pc appears to be reliable. We…”
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A study of the F-giant star θ Scorpii A: a post-merger rapid rotator? by Lewis, Fiona, Bailey, Jeremy, Cotton, Daniel V, Howarth, Ian D, Kedziora-Chudczer, Lucyna, van Leeuwen, Floor

“…ABSTRACT We report high-precision observations of the linear polarization of the F1III star θ Scorpii. The polarization has a wavelength dependence of the form…”
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The rotation of α Oph investigated using polarimetry by Bailey, Jeremy, Cotton, Daniel V, Howarth, Ian D, Lewis, Fiona, Kedziora-Chudczer, Lucyna

“…ABSTRACT Recently we have demonstrated that high-precision polarization observations can detect the polarization resulting from the rotational distortion of a…”
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Rapid polarization variations in the O4 supergiant ζ Puppis by Bailey, Jeremy, Howarth, Ian D, Cotton, Daniel V, Kedziora-Chudczer, Lucyna, De Horta, Ain, Martell, Sarah L, Eldridge, Colin, Luckas, Paul

“…ABSTRACT We present time-series linear-polarization observations of the bright O4 supergiant ζ Puppis. The star is found to show polarization variation on…”
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Time-series photometry of the O4 I(n)fp star ζ Puppis by Howarth, Ian D., Stevens, Ian R.

“…We report a time-series analysis of the O4 I(n)fp star ζPup, based on optical photometry obtained with the SMEI (Solar Mass Ejection Imager) instrument on the…”
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Two New Rapidly Rotating ON Stars Found with LAMOST by Li, Guang-Wei, Howarth, Ian D.

“…The ON stars are a rare subtype of O stars of uncertain origin. We report two new, rapidly rotating ON stars found in data acquired with the Large Sky Area…”
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Interstellar Absorption‐Line Evidence for High‐Velocity Expanding Structures in the Carina Nebula Foreground by Walborn, Nolan R., Smith, Nathan, Howarth, Ian D., Vieira Kober, Gladys, Gull, Theodore R., Morse, Jon A.

“…The extreme, high‐velocity interstellar absorption‐line profiles toward η Carinae and 16 neighboring stars in Trumpler 16 are examined, including several new…”
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Polarization due to rotational distortion in the bright star Regulus by Cotton, Daniel V., Bailey, Jeremy, Howarth, Ian D., Bott, Kimberly, Kedziora-Chudczer, Lucyna, Lucas, P. W., Hough, J. H.

“…Polarization in stars was first predicted by Chandrasekhar 1 , who calculated a substantial linear polarization at the stellar limb for a pure…”
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Two new Wolf-Rayet stars in the Large Magellanic Cloud by Howarth, Ian D., Walborn, Nolan R.

“…Abstract We report the discovery of two previously unknown WN3 stars in the Large Magellanic Cloud (LMC). Both are bright (15th magnitude), isolated and…”
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A 2dF survey of the Small Magellanic Cloud by Evans, Christopher J., Howarth, Ian D., Irwin, Michael J., Burnley, Adam W., Harries, Timothy J.

“…ABSTRACT We present a catalogue of new spectral types for hot, luminous stars in the Small Magellanic Cloud (SMC). The catalogue contains 4161 objects, giving…”
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Cross-correlation characteristics of OB stars from IUE spectroscopy by Howarth, Ian D., Siebert, Kaj W., Hussain, Gaitee A. J., Prinja, Raman K.

“…We present a catalogue of homogeneous measures of the linewidth parameter, ve sin i, for 373 O-type stars and early B supergiants (including the separate…”
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