Whole Earth Telescope observations of the highest amplitude rapidly oscillating Ap star known: 3 Weeks of observations at the SAAO

Lead Research Organisation: University of Central Lancashire
Department Name: Jeremiah Horrocks Institute

Abstract

We will conduct observations of a known rapidly oscillating chemically peculiar star as part of a whole earth telescope campaign. This type of star shows a very abnormal chemical signature in its atmosphere which is thought to arise as a result of their very strong magnetic fields. When analysing the brightness of these stars, the roAp stars, we see that they change in brightness on time scales of 3-21 minutes. This is a result of their atmospheres pulsating, causing changes in the star's temperature, and thus light output.
To study these stars in detail requires continuous data collection, something that is inhibited by the day/night cycle of the Earth. Our observations will form part of a Whole Earth Telescope campaign where many telescopes around the world observe the same star, removing the effect of the day/night cycle. In doing so, we can analyse the star in much better detail with the aim of discovering why the star behaves as it does. Of all the roAp stars, our target shows the most dramatic change in its brightness over time. Currently we are unsure the reason for this, but our observations will allow us to test many theories.

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