Calendar

Sep
20
Wed
Colloquium PhD Defense: Jean McKeever
Sep 20 @ 3:00 pm – 4:15 pm
Colloquium PhD Defense: Jean McKeever @ Business College 103

Asteroseismology of Red Giants: The Detailed Modeling of Red Giants in Eclipsing Binary Systems

Jean McKeever, NMSU

Asteroseismology is an invaluable tool that allows one to peer into the inside of a star and know its fundamental stellar properties with relative ease. There has been much exploration of solar-like oscillations within red giants with recent advances in technology, leading to new innovations in observing. The Kepler mission, with its 4-year observations of a single patch of sky, has opened the floodgates on asteroseismic studies. Binary star systems are also an invaluable tool for their ability to provide independent constraints on fundamental stellar parameters such as mass and radius. The asteroseismic scaling laws link observables in the light curves of stars to the physical parameters in the star, providing a unique tool to study large populations of stars quite easily. In this work we present our 4-year radial velocity observing program to provide accurate dynamical masses for 16 red giants in eclipsing binary systems. From this we find that asteroseismology overestimates the mass and radius of red giants by 15% and 5% respectively. We further attempt to model the pulsations of a few of these stars using stellar evolution and oscillation codes. The goal is to determine which masses are correct and if there is a physical cause for the discrepancy in asteroseismic masses. We find there are many challenges to modeling evolved stars such as red giants and we address a few of the major concerns. These systems are some of the best studied systems to date and further exploration of their asteroseismic mysteries is inevitable.

 

Jan
24
Wed
Colloquium Thesis Proposal: Laurel Farris
Jan 24 @ 2:30 pm – 3:30 pm
Colloquium Thesis Proposal: Laurel Farris @ Science Hall, Room 110

Characterizing the oscillatory response of the chromosphere during solar flares

Laurel Farris; NMSU Astronomy Department

Quasi-periodic pulsations (QPPs) are observed in the emission of solar flares over a wide range of wavelengths,

particularly in the radio and hard x-ray regimes where non-thermal emission dominates. These pulsations are

considered to be an intrinsic feature of flares, yet the exact mechanism that triggers them remains unclear.

There have been reports of an increase in the oscillatory power at 3-minute periods (the local acoustic

cutoff frequency) in the solar chromosphere associated with flaring events. I propose to investigate the

chromospheric response to flares by inspecting the spatial and temporal onset and evolution of the 3-minute

oscillatory power, along with any QPP patterns that may appear in chromospheric emission. The analysis

will be extended to multiple flares, and will include time before, during, and after the main event. To test

initial methods, the target of interest was the well-studied 2011 February 15 X-class flare. Data from two

instruments on board the Solar Dynamics Observatory (SDO) were used in the preliminary study, including

continuum images from the Helioseismic and Magnetic Imager (HMI) and UV images at 1600 and 1700

Angstroms from the Atmospheric Imaging Assembly (AIA). Later, spectroscopic data from the Interface

Region Imaging Spectrometer (IRIS) will be used to examine velocity patterns in addition to intensity.

Jan
26
Fri
Colloquium: Zheng Cai (Host: Kristian Finlator)
Jan 26 @ 3:15 pm – 4:15 pm
Colloquium: Zheng Cai (Host: Kristian Finlator) @ BX102

Colloquium Title

Colloquium Speaker Name, Affiliation

Abstract text

Jan
30
Tue
Astro-ph Discussion
Jan 30 @ 2:30 pm – 3:00 pm
Astro-ph Discussion @ AY119
Feb
1
Thu
Astro-ph Discussion
Feb 1 @ 2:30 pm – 3:00 pm
Astro-ph Discussion @ AY119
Feb
6
Tue
Astro-ph Discussion
Feb 6 @ 2:30 pm – 3:00 pm
Astro-ph Discussion @ AY119
Feb
8
Thu
Astro-ph Discussion
Feb 8 @ 2:30 pm – 3:00 pm
Astro-ph Discussion @ AY119
Feb
13
Tue
Astro-ph Discussion
Feb 13 @ 2:30 pm – 3:00 pm
Astro-ph Discussion @ AY119
Feb
15
Thu
Astro-ph Discussion
Feb 15 @ 2:30 pm – 3:00 pm
Astro-ph Discussion @ AY119
Feb
20
Tue
Astro-ph Discussion
Feb 20 @ 2:30 pm – 3:00 pm
Astro-ph Discussion @ AY119