English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present the first 1-D aperture synthesis imaging of the red supergiantBetelgeuse in the individual CO first overtone lines with VLTI/AMBER. Thereconstructed 1-D projection images reveal that the star appears differently inthe blue wing, line center, and red wing of the individual CO lines. The 1-Dprojection images in the blue wing and line center show a pronounced,asymmetrically extended component up to ~1.3 stellar radii, while those in thered wing do not show such a component. The observed 1-D projection images inthe lines can be reasonably explained by a model in which the CO gas within aregion more than half as large as the stellar size is moving slightly outwardwith 0--5 km s^-1, while the gas in the remaining region is infalling fast with20--30 km s^-1. A comparison between the CO line AMBER data taken in 2008 and2009 shows a significant time variation in the dynamics of the CO line-formingregion in the photosphere and the outer atmosphere. In contrast to the linedata, the reconstructed 1-D projection images in the continuum show only aslight deviation from a uniform disk or limb-darkened disk. We derive auniform-disk diameter of 42.05 +/- 0.05 mas and a power-law-type limb-darkeneddisk diameter of 42.49 +/- 0.06 mas and a limb-darkening parameter of (9.7 +/-0.5) x 10^{-2}. This latter angular diameter leads to an effective temperatureof 3690 +/- 54 K for the continuum-forming layer. These diameters confirm thatthe near-IR size of Betelgeuse was nearly constant over the last 18 years, inmarked contrast to the recently reported noticeable decrease in the mid-IRsize. The continuum data taken in 2008 and 2009 reveal no or only marginal timevariations, much smaller than the maximum variation predicted by the current3-D convection simulations.

Imaging the dynamical atmosphere of the red supergiant Betelgeuse in the CO first overtone lines with VLTI/AMBER