Title: The DODO Survey: Imaging Planets Arounds White Dwarfs

Authors: Emma Hogan, Matt Burleigh, Fraser Clarke

Abstract:

The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is 
to search for very low mass brown dwarfs and extrasolar planets in wide orbits 
around white dwarfs via direct imaging. 

White dwarfs can be up to 10,000 times less luminous than their main sequence 
progenitors, substantially increasing the probability of directly imaging a 
faint, low mass companion in orbit around them. The direct detection of such 
companions would allow the spectroscopic investigation of objects with 
temperatures much lower (<500K) than the coolest brown dwarfs currently 
observed. The detection of a planet around a white dwarf would prove that such 
objects can survive the final stages of stellar evolution and place 
constraints on the frequency of planetary systems around their progenitors 
(with masses between 1.5-8 solar masses, i.e., early B to mid F). 

This poster presents the results of a Gemini multi-epoch J band common proper 
motion survey of 23 nearby equatorial and northern hemisphere white dwarfs. We 
rule out the presence of any common proper motion companions, with limiting 
masses determined from the completeness limit of each observation, to 18 white 
dwarfs. For the remaining five targets, the motion of the white dwarf is not 
sufficiently separated from the non-moving background objects in each field. 
These targets require additional observations to conclusively rule out the 
presence of any common proper motion companions. From our completeness limits, 
we tentatively suggest that <5% of white dwarfs have substellar companions 
with effective temperatures >500K between projected physical separations of 
60-200AU.