Calendar

Sep
13
Fri
Colloquium: Eric Nielsen (Host: Moire Prescott)
Sep 13 @ 3:15 pm – 4:15 pm
Colloquium: Eric Nielsen (Host: Moire Prescott) @ BX102

Charting the Outer Reaches of Exoplanetary Systems: Wide-Separation Giant Planet Demographics with Direct Imaging

Eric Nielsen, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University

Over the past decade, the combination of advances in adaptive optics, coronagraphy, and data processing has enabled the direct detection and characterization of giant exoplanets orbiting young, nearby stars. In addition to the wealth of information about exoplanetary atmospheres we obtain from spectroscopy of directly imaged planets, the demographics of these wide-separation planets allow us to directly test theories of planet formation, probing the outer planetary systems compared to transit and radial velocity techniques. In this talk I will present results from the Gemini Planet Imager Exoplanet Survey (GPIES), which surveyed 521 nearby stars for giant planet and brown dwarf companions orbiting beyond 5 AU, and is one of the largest, deepest direct imaging searches for exoplanets every conducted. The overall occurrence rate of substellar companions, and trends with companion mass, semi-major axis, and stellar mass are consistent with giant planets forming via core accretion, and point to different formation mechanisms for giant planets and brown dwarfs between 10 and 100 AU.

 

Nov
15
Fri
Colloquium: Phil Judge (Host James McAteer)
Nov 15 @ 3:15 pm – 4:15 pm
Colloquium: Phil Judge (Host James McAteer) @ BX102

Using every photon to learn about the physics of solar plasmas

Phil Judge, High Altitude Observatory, Boulder CO.

The Sun has traditionally been the Rosetta Stone that can overcome the gap in regimes between laboratory and astronomical plasmas.   Theories applicable in the laboratory may not readily apply to solar plasmas, and vice-versa. Yet we still face challenges in understanding how the observable plasmas are produced, and why the magnetic field threading and energizing them must globally reverse every 11 years. I will give a general overview of currently pressing problems in solar physics, followed by two specific examples: one concerning the physics of flares through infrared spectroscopy and polarimetry, the other concerning how we might wring every last ounce of information from the emitted photons. Along the way I will introduce the NMSU-operated Dunn Solar Telescope, the new DKIST, Parker Solar Probe and Solar Orbiter, and suggest how we might take advantage of these new facilities to make lasting progress.

Nov
22
Fri
Colloquium: Rixin Li (Host: Wladimir Lyra)
Nov 22 @ 3:15 pm – 4:15 pm
Colloquium: Rixin Li (Host: Wladimir Lyra) @ BX102

Simulating Planetesimal Formation in the Kuiper Belt and Beyond

Rixin Li, University of Arizona

A critical step in planet formation is to build super-km-sized planetesimals in protoplanetary disks. The origin and demographics of planetesimals are crucial to understanding the Solar System, circumstellar disks, and exoplanets. I will overview the current status of planetesimal formation theory. Specifically, I will present our recent simulations of planetesimal formation by the streaming instability, a mechanism to aerodynamically concentrate pebbles in protoplanetary disks. I will then discuss the connections between our numerical models and recent astronomical observations and Solar System explorations. I will explain why all planetesimals likely formed as binaries.

Feb
6
Thu
Colloquium: RESERVED
Feb 6 @ 3:15 pm – 4:15 pm
Colloquium: RESERVED @ BX102

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Colloquium Speaker Name, Affiliation

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Feb
11
Tue
Remote Colloquium: RESERVED
Feb 11 @ 3:00 pm – 4:00 pm
Remote Colloquium: RESERVED @ MH 85

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Colloquium Speaker Name, Affiliation

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Feb
12
Wed
Remote Colloquium: RESERVED
Feb 12 @ 3:00 pm – 4:00 pm
Remote Colloquium: RESERVED @ MH 85

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Feb
13
Thu
Colloquium: RESERVED
Feb 13 @ 3:15 pm – 4:15 pm
Colloquium: RESERVED @ BX102

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Feb
17
Mon
Colloquium: RESERVED
Feb 17 @ 3:15 pm – 4:15 pm
Colloquium: RESERVED @ BX102

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Feb
19
Wed
Remote Colloquium: RESERVED
Feb 19 @ 1:00 pm – 2:00 pm
Remote Colloquium: RESERVED @ BX102

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Feb
20
Thu
Colloquium: RESERVED
Feb 20 @ 3:15 pm – 4:15 pm
Colloquium: RESERVED @ BX102

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