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Born Again Disks as Signposts for Planets
John H. DebesSpace Telescope Science Institute
Slide from B. Gaensicke
Slide from B. Gaensicke
Slide from B. Gaensicke
Dusty White Dwarfs are Signposts for
Planets• In 1987, the ZZ Ceti G29-38 was discovered to have an infrared excess
• Excess first attributed to brown dwarf, eventually attributed to dust (i.e. Graham et al., 1991) Zuckerman & Becklin
(1987)
Data from Reach et al. (2005)
Rin=10 RWD
Rout=30 RWD
StructureAfter Jura (2003), Jura et al., (2007), Reach et al., (2009)
Dust Sublimation Tidal Disruption Radius
Slide from B. Gaensicke
Gaseous WD Disks Are Signposts
Metal line White Dwarfs are
Signposts for Planets• G29-38 also
showed absorption lines due to Ca, Mg, and Fe
• Large telescopes with high resolution spectrographs discovered that 25% of WDs have metal pollution (Zuckerman et al., 2003; Koester et al., 2005)Debes et al. (2010)
CompositionZuckerman et al. (2007)
COS can find exquisite
abundances
Gaensicke et al. (2011, in prep)
+ =
Planetesimal Survival
Dong et al., (2010)
Survival of Planetesimals
Sublimation
Lmax=2x104 Lʘ
Gas Drag
3 Mʘ
1.5 Mʘ
1 MʘLmax=104 Lʘ
How do you get asteroids in?
Debes & Sigurdsson (2002)
Unstable Planets
Bonsor et al., (2011)
Exterior Resonances
Debes et al., in prep
Interior Resonances
Accretion from Interior
Resonances
Gaensicke COS Survey
Debes et al., in prep
Predict Belt Masses from Polluted WDs
Debes et al., in prep
For more info, check out this
new book!
Wide-field Infrared Survey Explorer
WISE Mission Overview
Salient FeaturesSalient Features• 4 imaging channels covering 3 - 25 microns 4 imaging channels covering 3 - 25 microns
wavelengthwavelength• 40 cm telescope operating at <17K40 cm telescope operating at <17K• Two stage solid hydrogen cryostatTwo stage solid hydrogen cryostat
• Delta launch from WTR on December 14, 2009 Delta launch from WTR on December 14, 2009 • Sun-synchronous 6am/6pm 500km orbitSun-synchronous 6am/6pm 500km orbit• Scan mirror provides efficient mappingScan mirror provides efficient mapping
• Operational life: estimate 11 monthsOperational life: estimate 11 months• 4 TDRSS tracks per day4 TDRSS tracks per day
Salient FeaturesSalient Features• 4 imaging channels covering 3 - 25 microns 4 imaging channels covering 3 - 25 microns
wavelengthwavelength• 40 cm telescope operating at <17K40 cm telescope operating at <17K• Two stage solid hydrogen cryostatTwo stage solid hydrogen cryostat
• Delta launch from WTR on December 14, 2009 Delta launch from WTR on December 14, 2009 • Sun-synchronous 6am/6pm 500km orbitSun-synchronous 6am/6pm 500km orbit• Scan mirror provides efficient mappingScan mirror provides efficient mapping
• Operational life: estimate 11 monthsOperational life: estimate 11 months• 4 TDRSS tracks per day4 TDRSS tracks per day
ScienceScience• Sensitive all sky survey with 8X redundancySensitive all sky survey with 8X redundancy
– Find the most luminous galaxies in the universe– Find the closest stars+brown dwarfs to the sun– Provide an important catalog for JWST– Provide lasting research legacy
ScienceScience• Sensitive all sky survey with 8X redundancySensitive all sky survey with 8X redundancy
– Find the most luminous galaxies in the universe– Find the closest stars+brown dwarfs to the sun– Provide an important catalog for JWST– Provide lasting research legacy
National Aeronautics and Space Administration
Jet Propulsion LaboratoryCalifornia Institute of Technology
• Dominic Benford - GSFC• Andrew Blain - Caltech• Martin Cohen - UCB• Roc Cutri - IPAC• Peter Eisenhardt -JPL• Nick Gautier - JPL• Tom Jarrett - IPAC• Davy Kirkpatrick - IPAC• David Leisawitz - GSFC• Carol Lonsdale - NRAO
• Amy Mainzer - JPL• John Mather - GSFC• Ian McLean - UCLA• Robert McMillan - UA• Bryan Mendez - UCB• Deborah Padgett - IPAC• Michael Ressler - JPL• Michael Skrutskie - UVa• Adam Stanford - LLNL• Russell Walker - MIRA
PI: Edward L. Wright - UCLA
National Aeronautics and Space Administration
Jet Propulsion LaboratoryCalifornia Institute of Technology
The WIRED Team
Stefanie Wachter, (IPAC, lead)
Don W. Hoard (IPAC)Dave T. Leisawitz (GSFC)
Martin Cohen (MIRA)
WISE Nominal
Sensitivities
Debes et al., ApJS, submitted
Debes et al., ApJS, submitted
Known Disk
Circumbinary Dust
Known WDs
The Take Home Messages
•Dusty/Polluted/Gaseous Disk WDs need at least ONE giant planet to exist
•Mass and location of such planets may be constrained (and observed in the future with HST/JWST)
• IR+photospheric absorption lines give you detailed composition of exoasteroids
Take Home Messages-2•WIRED will provide a host of new
candidates that need to be confirmed and characterized
•WIRED will provide variability info for known dusty white dwarfs
•WISE will provide legacy information as known WDs become complete to ~100pc (currently, only complete to ~20pc)
•Preliminary WISE catalogue is publicly available