Archive for June, 2016

Jupiter paper with amateur images

Posted June 12, 2016 By grigoris

A recent paper, discussing radio observations to probe Jupiter’s atmosphere below its visible cloud layers, makes use of images obtained in the visible domain by amateurs (among who is Manos Kardasis).
They investigate ammonia gas from ~0.5 to ~10 bar (almost 100 km deep), and how it is distributed in a 3D “map”. Ammonia is driven from deep in the atmosphere to the upper layers and as it cools down it creates icy clouds, while the remaining air sinks down from regions without ammonia. The various radio bright/dark regions correlate well with features visible in the ir (e.g. 5μm hot spots) and visible (e.g. the Great Red Spot, white ovals), providing a link between these features and their driving mechanisms from within the atmosphere.

Imke de Pater, R. J. Sault, Bryan Butler, David DeBoer, Michael H. Wong
“Peering through Jupiter’s clouds with radio spectral imaging”
Science, 2016, 352, 1198
(links: Science, Berkeley News, The Gurdian)

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Poster presentation at RAS meeting in UK

Posted June 11, 2016 By grigoris

The very short and compact meeting of the Royal Astronomical Society “Bridging the gap: from massive stars to supernovae” was held in Kavli Royal Society Centre of Chicheley Hall, in the English countryside of Buckinghamshire (June 1-2). Even though it lasted two days only, a number of excellent talks was delivered discussing the connection or the gap (depending on the perspective) between the massive stars and supernovae, proving that we know some things but a lot has to be done.

I had the opportunity to present a poster (pdf file) entitled: “B[e] Supergiants’ circumstellar environment: disks or rings?” with the following abstract:

Extreme mass-loss activity characterize some phases of evolution of massive stars (such as Luminous Blue Variables, Yellow Hypergiants, B[e] Supergiants), which strongly affects the stars and their circumstellar environment almost before they become Supernovae. Currently, our understanding of these phases it not well-established, such as the lack of B[e] Supergiants (B[e]SGs) predicted from stellar evolution theory. In order to improve our knowledge for the particular class of B[e]SGs we have initiated a campaign to investigate the structure of their circumstellar material, which consists of a complex combination of atomic, molecular and dust regions of different temperatures and densities. We obtained high-resolution optical and near-infrared spectra (using MPG-ESO/FEROS, GEMINI/Phoenix and VLT/CRIRES, respectively) for a number of Galactic B[e]SGs. We examine the [OI] and [CaII] emission lines and the CO bandheads to probe the structure and the kinematics of their formation regions. We find that these emission lines form in a series of single and/or multiple equatorial rings, a probable result of previous mass-loss events.

My poster displayed.

My poster displayed.

A view of Chicheley Hall.

A view of Chicheley Hall.

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