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Searching for White Dwarf Exoplanets:. WD 2359-434 Case Study. Bruce Gary, Arizona 14-inch T.G. Tan, Australia 12-inch Ivan Curtis, Australia 11-inch Paul Tristram , New Zealand 24-inch Akihiko Fukui, Japan ( ” ).
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Searching for White Dwarf Exoplanets: WD 2359-434 Case Study
Bruce Gary, Arizona 14-inch • T.G. Tan, Australia 12-inch • Ivan Curtis, Australia 11-inch • Paul Tristram, New Zealand 24-inch • Akihiko Fukui, Japan ( ” )
Background • PAWM (Pro-Am White dwarf Monitoring), 2011 • 25 amateurs, 46 WDs, no exoplanet transits • However, 3 WDs were variable (surprise) • WD 2354-434 was the most interesting • WDs are small (same size as Earth) • Hot Jupiters are much bigger, & can orbit close • Therefore, big planets can reflect WD light and produce variations
But so can an orbiting exoplanet • Planet radius = 1.23 x Jupiter • Orbit distance = 0.0042 a.u. (for P = 2.7 hrs) • Orbit inclination close to edge-on • Slightly too close for “habitable zone”
Follow-Up Observations Needed • Radial velocity (to see if hypothetical exoplanet is on far side when brightest) • Spectroscopy to check idea of 1) Lyman-alpha emission is coming from planet atmosphere & 2) convection bringing He to surface (e.g., never-before seen spot) • All of above require professional hardware
Conclusions • Discovering exoplanets around WDs is within reach of amateurs! • But professional collaboration (follow-up) will be needed.