White Dwarfs, Planets, Disks Marc Kuchner NASA Goddard Space Flight Center

1. White Dwarfs, Planets, Disks Marc Kuchner NASA Goddard Space Flight Center Laboratory for Exoplanets and Stellar Astrophysics

2. Laboratory for Exoplanets and Stellar Astrophysics NASA Postdoctoral Program: http://nasa.orau.org/postdoc/ Exoplanet Talks: http://eud.gsfc.nasa.gov/ Marc.Kuchner/exoplanetclub.html

3. Bill Reach (IPAC) Ted von Hippel, Don Winget, Mukremin Kilic, Fergal Mullaly (UT Austin) Adam Burrows (U. Arizona) White Dwarf Spitzer Space Telescope

4. Zuckerman & Becklin 1987 1200 K 0.15 Rsun ~40 Jupiter masses by age and T White Dwarf G29-38 Wavelength (microns)

5. H x=0.75 Radius (Earth Radii) He C Mg White Dwarf Fe log mass (solar masses)

6. G29-38b ? HD209458b Jupiter Radius (Earth Radii) log mass (solar masses)

7. Metal, Carbon, Or Unidentified Hydrogen Surface No Lines from Surface! Helium Surface DZ DQ DO DC DB DA DX Carbon and Oxygen Core 75% 10% 5% 10%

8. Hydrogen Surface with Metals DAZ CO core ~20% of DAs, including G29-38

9. Bergeron et al. 2004 Log g DA Instability Strip Teff (K)

10. 615s Patterson et al. 1991 23 JUL 1988 B-band Power 24 JUL 1988 K-band

12. Deuterium Burning Limit Debes et al. 2005 Pulsation Timing (Kleinman et al. 1998) & speckle photometry (Kuchner et al. 1998) HST/Gemini Photometry (Debes et al. 2005) MJupiter Log R (AU)

16. e.g. Debes & Sigurdsson 2002, Jura et al. 2003

18. White Dwarf Spitzer Space Telescope

19. Jupiter at 5 microns w/ ISO (Encrenaz et al. 1997)

20. Spitzer photometry Typical WD ages since formation of progenitor are 1.5 - 3.5  109 years. 0.3 0.2 0.1 0.0 109 yr. Planet/WD at 4.5 microns 3  109 yr. 0 5 10 15 Planet mass (MJupiter)

22. Bergeron et al. 1994 CIA

23. Without the mid IR data: 5400 K, 3.5 Gyr old. With the mid IR data: 5200 K, 4.5 Gyr old Kilic et al. 2006, ApJ, in press Same Models w/ CIA New Spitzer Photometry

24. All Hydrogen WDs below ~7000 K show an 8 micron deficit! DZ F8m/FV FJ/FV

25. Galactic Disk: 8 +/- 1.5 Gyr

26. A New Dusty WD! Von Hippel et al., in prep

27. Plus 2 more from IRTF and one from Farihi et al makes 5! Kilic et al., in prep GD 56 Becklin & Zuckerman 1987 Kilic et al. 2005 Becklin et al. 2005

31. Reach et al. 2005 1-10RSun 0.01-1000 m grains dn/da  a-3.5 C:O ratio 3:1 Amorphous carbon needed to match 1.6 m spectrum amorphous olivine forsterite

32. Livio, Pringle & Saffer 1992

33. H x=0.75 Radius (Earth Radii) He CO Giant C Mg White Dwarf Fe log mass (solar masses)

34. C:O ratio in gas 9:1 Roberge et al. in press

35. T Tauri Stars -- Spitzer 11.3 micron C-H out-of-plane bend Geers et al 2005

39. Youdin & Chiang 2004 Particle Plieups

40. Lodders & Fegley 1997

41. Enstatite Chondrites? Gas and Graphite Wood & Hashimoto 1993 Cohenite SiC Forsterite Fe Enstatite Atomic Fraction

43. Gaidos 2000 Kuchner & Seager 2005

44. Artist: Lynette Cook

45. Solar Composition Kuchner & Seager 2005

46. Carbon Planet Kuchner & Seager 2005

47. Kuchner & Seager 2005

48. Kuchner & Seager 2005

49. Konacki & Wolzsczan 03 w/o planets with non- interacting planets Time of Arrival Residuals (s) with real planets

50. Key Points Cool Hydrogen WDs have mid-IR deficits; the inferred age of the Galactic disk is wrong by ~25%. Roughly 1/4 DAZ WDs are dusty. The dust sometimes has silicates----but it may be C rich (e.g. G29-38). Carbon planets may be common; we can recognize them if they are hot. New Exoplanet Lab at Goddard: come join us as a postdoc or as a speaker!