Presenter Information

Austen Stone

Document Type

Oral Presentation

Location

SURC Ballroom B/C/D

Start Date

21-5-2015

End Date

21-5-2015

Keywords

Astrophysiscs, Solar Phyiscs, Sigmoid

Abstract

This project’s purpose was to study how the speed at which the plasma in the photosphere of the sun affects the lifetime and shape of a solar sigmoid. Solar sigmoids are S-shaped, twisted magnetic structures that are due to the shifting magnetic field lines emerging from the surface of the sun. The photosphere is the visible layer of the sun’s surface and is made up of cells of plasma that are highly conductive and influenced by the magnetic field of the sun. Sigmoids form when shearing (a lateral shift between two objects in directions opposite each other) occurs in the photosphere plasma, causing ropes of magnetic flux to break and reconnect in S shapes. I predicted that when higher velocity shearing occurs in this plasma, solar sigmoid structures will be stretched out and as a result be less stable, extending just above the surface of the sun, and at a lower shearing velocity a sigmoid will stay stable longer and be able to extend much further above the surface of the sun. The shear velocity of the photosphere at the base of the sigmoid was measured using the physics-based Tracker software, which takes user-uploaded videos and helps measure changes in position of an object within the video. This project was carried out using the Helioseismic and Magnetic Imager (HMI) and atmospheric Imaging Assembly onboard the Solar Dynamics Observatory (SDO) to retrieve magnetogram time lapse data and both partial and full solar view time-lapse data.

Poster Number

59

Faculty Mentor(s)

Darci Snowden

Department/Program

Physics

Additional Mentoring Department

Physics

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May 21st, 8:30 AM May 21st, 11:00 AM

Predicting Solar Sigmoid Lifetimes Based on Shearing in the Photosphere

SURC Ballroom B/C/D

This project’s purpose was to study how the speed at which the plasma in the photosphere of the sun affects the lifetime and shape of a solar sigmoid. Solar sigmoids are S-shaped, twisted magnetic structures that are due to the shifting magnetic field lines emerging from the surface of the sun. The photosphere is the visible layer of the sun’s surface and is made up of cells of plasma that are highly conductive and influenced by the magnetic field of the sun. Sigmoids form when shearing (a lateral shift between two objects in directions opposite each other) occurs in the photosphere plasma, causing ropes of magnetic flux to break and reconnect in S shapes. I predicted that when higher velocity shearing occurs in this plasma, solar sigmoid structures will be stretched out and as a result be less stable, extending just above the surface of the sun, and at a lower shearing velocity a sigmoid will stay stable longer and be able to extend much further above the surface of the sun. The shear velocity of the photosphere at the base of the sigmoid was measured using the physics-based Tracker software, which takes user-uploaded videos and helps measure changes in position of an object within the video. This project was carried out using the Helioseismic and Magnetic Imager (HMI) and atmospheric Imaging Assembly onboard the Solar Dynamics Observatory (SDO) to retrieve magnetogram time lapse data and both partial and full solar view time-lapse data.