Chris and the Middle Kingdom Chris Ormel

Hubble Fellow
University of California, Berkeley

ormel AT astro DOT berkeley DOT edu




News Flashes

July 2013
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dust growth in star and planet forming environments

Following the massive PPVI onslaught, Chris attended a more informal and more focused meeting on dust, dust, and more dust.

[Meeting Link] [Presentation]

July 2013
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Protostars and Planets VI

Chris travels to humid Heidelberg for this once-in-a-decade mega-conference, where scientist review the progress of the star and planet formation fields.

[Meeting Link] [Poster]

June 2013
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Victoria meeting

Chris travels to "British Victoria" to attend the International Astronomical Union symposium #299: Exploring the formation and evolution of planetary systems. Here he presents his results on the structure of gas flows surrounding planets in an exciting poster.

[Meeting Link] [Poster]

May 2013
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Runaway accretion in turbulent disks... rather problematic!


Comparison of turbulent motions (black dashed), strength curves (red solid and dashed) and the escape velocity (blue)

The classical idea in planet-formation theory is the following: A) planetesimals (~km-size bodies) form out of dust; B) they quickly produce a few protoplanetary seeds; C) these protoplanets sweep-up the leftover planetesimals; D) (proto)planets then accrete gas, migrate (possibly), and experience dynamical interactions before settling into a stable configuration.

We wondered whether phase B is compatible with a turbulent protoplanetary disks, for which nature there are ample indications. The short answer is: not really. ...

[More...] [ADS 1] [ArXiv 1] [ADS 2] [ArXiv 2]

March 2013
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Japan visit

Chris attended the kick-off meeting of the new ELSI institute and visits his collaborators at Tokyo Tech and Nagoya University.

March 2013
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Hubble symposium

Chris attends the Hubble Fellows symposium in snowy Baltimore. Afterwards, he visits Hanno Rein at the Institute for Advanced Studies in Princeton.

[Meeting Link]

January 2013
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SWRI colloquium

Chris travels to low-humidity Boulder Colorado, presenting his results during a colloquium at the South-West Research Insitute (SWRI) and also visits JILA. He enjoyed chatting with Katherine Kretke, Hal Levison, Andy Youdin and many other fellow planet formation gurus.

January 2013
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The flow pattern past gravitating bodies

Pantha rhei ("Everything flows"—Heraclitus, ~500 BC); but how do gravitating bodies like planets affect the flow pattern of the gas that attempts to stream past? When protoplanetary embryos made from accumulation of solid particles exceed a certain threshold mass (corresponding to ~1000 km in size), they can start to bind the gas from the nebula disk. The atmospheres of these young, low mass planets are (presumably) hot; generally, the gas does not collapse onto the planet and the atmosphere is in pressure-equilibrium with the disk. In fact, the boundary between planet and nebular disks has to be determined from the velocity of the flow....

[More...] [ADS] [ArXiv]