DISTANCE SCALE ZERO POINTS FROM GALACTIC RR LYRAE STAR PARALLAXES
- G. Benedict, B. Mcarthur, W. Freedman
- Physics
- 26 September 2011
We present new absolute trigonometric parallaxes and proper motions for seven Population II variable stars—five RR Lyr variables: RZ Cep, XZ Cyg, SU Dra, RR Lyr, and UV Oct; and two type 2 Cepheids:…
An excess of massive stars in the local 30 Doradus starburst
- F. Schneider, H. Sana, C. Norman
- Physics, GeologyScience
- 5 January 2018
The recent formation history and the initial mass function (IMF) of massive stars in 30 Doradus is determined on the basis of spectroscopic observations of 247 stars more massive than 15 solar masses, and the main episode of massive star formation began about 8 million years ago and seems to have declined in the last 1 My.
The effect of rotation on the abundances of the chemical elements of the A-type stars in the Praesepe cluster ?
- L. Fossati, S. Bagnulo, M. Gebran
- Physics
- 25 March 2008
Aims. We study how chemical abundances of late B‐, A‐ and early F‐type stars evolve with time, and we search for correlations between the abundance of chemical elements and other stellar parameters,…
METALS IN THE EXOSPHERE OF THE HIGHLY IRRADIATED PLANET WASP-12b
- L. Fossati, C. Haswell, D. Wilson
- Physics, Geology
- 10 May 2010
The results are strong evidence for an extended absorbing exosphere surrounding the planet, and the NUVA data exhibit an early ingress, contrary to model expectations; it is speculated this could be due to the presence of a disk of previously stripped material.
A DETAILED SPECTROPOLARIMETRIC ANALYSIS OF THE PLANET-HOSTING STAR WASP-12,
- L. Fossati, S. Bagnulo, L. Hebb
- Physics, Geology
- 19 July 2010
The knowledge of accurate stellar parameters is paramount in several fields of stellar astrophysics, particularly in the study of extrasolar planets, where often the star is the only visible…
Confronting uncertainties in stellar physics: calibrating convective overshooting with eclipsing binaries
- R. Stancliffe, L. Fossati, Jean-Claude Passy, Fabian R. N. Schneider AIfA, Oxford
- Physics, Geology
- 21 January 2015
As part of a larger program aimed at better quantifying the uncertainties in stellar computations, we attempt to calibrate the extent of convective overshooting in low to intermediate mass stars by…
Stellar Spectropolarimetry with Retarder Waveplate and Beam Splitter Devices
- S. Bagnulo, M. Landolfi, J. Landstreet, E. Landi Degl’Innocenti, L. Fossati, M. Sterzik
- Physics
- 20 August 2009
Nighttime polarimetric measurements are often obtained very close to the limits of the instrumental capabilities. It is important to be aware of the possible sources of spurious polarization, and to…
NEAR-ULTRAVIOLET ABSORPTION, CHROMOSPHERIC ACTIVITY, AND STAR–PLANET INTERACTIONS IN THE WASP-12 SYSTEM
- C. Haswell, L. Fossati, A. Carter
- Physics, Geology
- 20 November 2012
Extended gas clouds have been previously detected surrounding the brightest known close-in transiting hot Jupiter exoplanets, HD 209458 b and HD 189733 b; we observed the distant but more extreme…
Searching for links between magnetic fields and stellar evolution: II. The evolution of magnetic fie
- J. Landstreet, S. Bagnulo, G. Wade
- Physics
- 3 June 2007
Context. The evolution of magnetic fields in Ap stars during the main sequence phase is presently mostly unconstrained by observation because of the difficulty of assigning accurate ages to known…
WTS-2 b: a hot Jupiter orbiting near its tidal destruction radius around a K dwarf
- J. Birkby, M. Cappetta, R. Tata
- Geology, Physics
- 21 February 2014
We report the discovery of WTS-2 b, an unusually close-in 1.02-d hot Jupiter (M-P = 1.12M(J), R-P = 1.30R(J)) orbiting a K2V star, which has a possible gravitationally bound M-dwarf companion at 0.6…
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