Event Title

Calculating orbits of eclipsing binaries with APOGEE spectra: the low-n limit

Research Mentor(s)

Kevin Covey

Description

The relation between the mass of a star and its radius remains uncertain, particularly for low mass stars. One of the reasons for the uncertainty is the difficulty of measuring masses and radii for the same stars. Eclipsing binaries are unique systems that allow us to measure a star’s mass and radius from the dimming that occurs when stars block one another. Mass and radius measurements have revealed that low mass stars have larger radii than theoretical models predict, by as much as 5%. We are analyzing the orbital motions of stars previously identified as showing eclipses, to better understand the stellar mass/radius relation. Using infrared spectra from APOGEE, we are analyzing precomputed cross-correlation functions (CCFs) of known eclipsing binaries to determine whether there is a strong contribution from each star in the spectrum. We then measure radial velocities (RVs) for stars in the most clearly separable binaries by fitting a gaussian to each star’s CCF peak. From phasing these RVs onto the orbital period from each system we will be able to better constrain their individual masses and to better constrain the models relating stellar masses to their radii.

Document Type

Event

Start Date

15-5-2019 9:00 AM

End Date

15-5-2019 5:00 PM

Location

Carver Gym (Bellingham, Wash.)

Department

Physics/Astronomy

Genre/Form

student projects, posters

Type

Image

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.

Language

English

Format

application/pdf

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May 15th, 9:00 AM May 15th, 5:00 PM

Calculating orbits of eclipsing binaries with APOGEE spectra: the low-n limit

Carver Gym (Bellingham, Wash.)

The relation between the mass of a star and its radius remains uncertain, particularly for low mass stars. One of the reasons for the uncertainty is the difficulty of measuring masses and radii for the same stars. Eclipsing binaries are unique systems that allow us to measure a star’s mass and radius from the dimming that occurs when stars block one another. Mass and radius measurements have revealed that low mass stars have larger radii than theoretical models predict, by as much as 5%. We are analyzing the orbital motions of stars previously identified as showing eclipses, to better understand the stellar mass/radius relation. Using infrared spectra from APOGEE, we are analyzing precomputed cross-correlation functions (CCFs) of known eclipsing binaries to determine whether there is a strong contribution from each star in the spectrum. We then measure radial velocities (RVs) for stars in the most clearly separable binaries by fitting a gaussian to each star’s CCF peak. From phasing these RVs onto the orbital period from each system we will be able to better constrain their individual masses and to better constrain the models relating stellar masses to their radii.