Imaging the spotty surface of Betelgeuse in the<i>H</i>band

Haubois, X.; Perrin, G.; Lacour, S.; Verhoelst, Tijl; Meimon, Serge; Mugnier, Laurent M.; Thiébaut, Éric; Berger, J.‐P.; Ridgway, Stephen T.; Monnier, John D.; Millan-Gabet, R.; Traub, Wesley A.

doi:10.1051/0004-6361/200912927

Cited by 159 publications

(197 citation statements)

References 74 publications

Supporting

Mentioning

171

Contrasting

Order By: Relevance

“…MiRA is capable of dealing with any available interferometric data (complex visibilities, squared visibilities, closure phases, etc. ), and has been successfully used to process real data (e.g., Lacour et al 2008;Lacour et al 2009;Le Bouquin et al 2009;Haubois et al 2009). When phases are missed because of the atmospheric turbulence, the MiRA algorithm can directly fit the available interferometric observables without explicitly rebuilding the missing phases.…”

Section: Image Reconstruction By Miramentioning

confidence: 99%

Milli-arcsecond images of the Herbig Ae star HD 163296

Renard

Malbet

Benisty³

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

Context. The very close environments of young stars are the hosts of fundamental physical processes, such as planet formation, stardisk interactions, mass accretion, and ejection. The complex morphological structure of these environments has been confirmed by the now quite rich data sets obtained for a few objects by near-infrared long-baseline interferometry. Aims. We gathered numerous interferometric measurements for the young star HD 163296 with various interferometers (VLTI, IOTA, KeckI and CHARA), allowing for the first time an image independent of any a priori model to be reconstructed. Methods. Using the Multi-aperture image Reconstruction Algorithm (MiRA), we reconstruct images of HD 163296 in the H and K bands. We compare these images with reconstructed images obtained from simulated data using a physical model of the environment of HD 163296.Results. We obtain model-independent H and K-band images of the surroundings of HD 163296. The images detect several significant features that we can relate to an inclined asymmetric flared disk around HD 163296 with the strongest intensity at about 4-5 mas. Because of the incomplete spatial frequency coverage, we cannot state whether each of them individually is peculiar in any way. Conclusions. For the first time, milli-arcsecond images of the environment of a young star are produced. These images confirm that the morphology of the close environment of young stars is more complex than the simple models used in the literature so far.

show abstract

Section: Image Reconstruction By Miramentioning

confidence: 99%

Milli-arcsecond images of the Herbig Ae star HD 163296

Renard

Malbet

Benisty³

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…After all, they only represent approximations to model atmospheres. Direct measurements of LD can only be carried out for a few exceptional stars with a spatially resolved surface, such as Betelgeuse (Haubois et al 2009) using interferometric observations or, most notably, our Sun (Neckel & Labs 1994).…”

Section: Introductionmentioning

confidence: 99%

High-precision stellar limb-darkening measurements

Müller

Huber

Czesla

et al. 2013

A&A

View full text Add to dashboard Cite

Context. Planetary transit light curves are influenced by a variety of fundamental parameters, such as the orbital geometry and the surface brightness distribution of the host star. Stellar limb darkening (LD) is therefore among the key parameters of transit modeling. In many applications, LD is presumed to be known and modeled based on synthetic stellar atmospheres. Aims. We measure LD in a sample of 38 Kepler planetary candidate host stars covering effective temperatures between 3000 K and 8900 K with a range of surface gravities from 3.8 to 4.7. In our study we compare our measurements to widely used theoretically predicted quadratic limb-darkening coefficients (LDCs) to check their validity. Methods. We carried out a consistent analysis of a unique stellar sample provided by the Kepler satellite. We performed a Markov chain Monte Carlo (MCMC) modeling of low-noise, short-cadence Kepler transit light curves, which yields reliable error estimates for the LD measurements in spite of the highly correlated parameters encountered in transit modeling. Results. Our study demonstrates that it is impossible to measure accurate LDCs by transit modeling in systems with high impact parameters (b 0.8). For the majority of the remaining sample objects, our measurements agree with the theoretical predictions, considering measurement errors and mutual discrepancies between the theoretical predictions. Nonetheless, theory systematically overpredicts our measurements of the quadratic LDC u 2 by about 0.07. Systematic errors of this order for LDCs would lead to an uncertainty on the order of 1% for the derived planetary parameters. Conclusions. We find that it is adequate to set the commonly used theoretical LDCs as fixed parameters in transit modeling. Furthermore, it is even indispensable to use theoretical LDCs in the case of transiting systems with a high impact parameter, since the host star's LD cannot be determined from their transit light curves.

show abstract

“…Unfortunately, these observations were not precise enough to distinguish between different model stellar atmospheres. Advances in interferometric observations have allowed for observations of convective cells in Betelgeuse (Haubois et al 2009) and measurements of gravity darkening in Altair (van Belle et al 2001). In terms of model stellar atmospheres, Aufdenberg et al (2005) constrained threedimensional models using observations of Procyon.…”

Section: Introductionmentioning

confidence: 99%

Spherically-symmetric model stellar atmospheres and limb darkening

Neilson

Lester

2013

A&A

View full text Add to dashboard Cite

Model stellar atmospheres are fundamental tools for understanding stellar observations from interferometry, microlensing, eclipsing binaries and planetary transits. However, the calculations also include assumptions, such as the geometry of the model. We use intensity profiles computed for both plane-parallel and spherically symmetric model atmospheres to determine fitting coefficients in the BVRIHK, CoRot and Kepler wavebands for limb darkening using several different fitting laws, for gravity-darkening and for interferometric angular diameter corrections. Comparing predicted variables for each geometry, we find that the spherically symmetric model geometry leads to different predictions for surface gravities log g < 3. In particular, the most commonly used limb-darkening laws produce poor fits to the intensity profiles of spherically symmetric model atmospheres, which indicates the need for more sophisticated laws. Angular diameter corrections for spherically symmetric models range from 0.67 to 1, compared to the much smaller range from 0.95 to 1 for plane-parallel models.

show abstract

Imaging the spotty surface of Betelgeuse in theHband

Cited by 159 publications

References 74 publications

Milli-arcsecond images of the Herbig Ae star HD 163296

Milli-arcsecond images of the Herbig Ae star HD 163296

High-precision stellar limb-darkening measurements

Spherically-symmetric model stellar atmospheres and limb darkening

Contact Info

Product

Resources

About