SPAMS: The Search for Planets Around post-Main Sequence Stars

Advisor: Brett Morris

Description: As of September 2015 more than 5000 exoplanets, or planets orbiting stars other than the Sun, have been discovered. The most successful planet discovery method to date is the “transit method”, which discovers planets by carefully monitoring the brightness of stars. If a star has an orbiting planet and its orbit brings the planet between the Earth and its host star, we can detect a slight dimming in the brightness of the host star during a “transit event” as the planet blocks out some of the star’s light. The Kepler Mission has discovered more than 4000 candidate planets this way, but it mostly focused on searching for planets orbiting “middle-aged” stars like the Sun.

One question that was not answered by the Kepler mission is: what happens to the Kepler planets after their Sun-like host stars die? The Sun will reach the last stage in its life cycle when it becomes a white dwarf – a very dense, small, hot star, roughly the size of the Earth. In the transition to the white dwarf phase, Mercury, Venus and maybe Earth are likely to be swallowed up by the swollen Sun, but more distant planets may survive. Some white dwarfs have been discovered that have metal pollution in their atmospheres, indicative of planetary material raining onto the surface of the star – is that planetary material a destroyed planet? Can we find zombie planets that survive the inferno of stellar death around these still white-hot dead stars?

The goal of this project will be to work with photometry (time-series brightness measurements) of white dwarfs collected by two of last years’ Pre-MAP students from the ARC 3.5 m telescope and the ARCSAT 0.5 m telescope at the Apache Point Observatory. We will search these measurements for transits of undiscovered exoplanets, and put constraints on the minimum size of detectable planets in those data. We will also re-evaluate the SPAMS search strategy and update the SPAMS metal-polluted white dwarf database with recent discoveries. We will observe more white dwarfs with the ARCSAT 0.5 m telescope (remotely) if weather permits. Pending any planets discovered, you will also achieve ultimate glory.

Project Skills: Unix, Python