student profile: Mr Daniel Hey


Thesis work

Thesis title: Asteroseismology of Binary and Chemically Peculiar Stars

Supervisors: Simon MURPHY , Timothy BEDDING

Thesis abstract:

Pulsations in variable stars can be used as precise clocks. In a binary system, a pulsating star’s orbit around a barycentre leads to a change in path length for the signal to reach Earth. By measuring these changes we can produce a series of time-delays in which the binarity of the system manifests as a periodic modulation of the signal. Fourier analysis of this time-delay yields parameters of the binary orbit, including period, eccentricity, angle of ascending node, and time of periastron passage. In a similar manner, differentiating the time-delay curve yields the full radial-velocity solution directly from the Kepler photometry, without the need for spectroscopy. This method uniquely covers the intermediate period binaries of 100 to 1000 days where the statistics of binary populations are least complete.

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