Are Planets in Unresolved Candidates of Debris disks stars?

1. Are Planets in Unresolved Candidates of Debris disks stars? R. de la Reza (1), C. Chavero (1), C.A.O. Torres (2) & E. Jilinski (1)(1) Observatorio Nacional - Rio de Janeiro (2) Laboratorio Nacional de Astrofísica

2. Properties Debris disks are evolved disks presenting the following properties: 1) in general absence or few gas content 2) structural pattern dominated by new generation dust produced by strong collisions of planetesimals 3) in general disks are assymmetrical 4) presence of warps and local perturbations of the dust 5) longlife structures 6) difficult to be detected, only approximatley 12 are resolved

3. Questions 1) are there planets hidden in their disks ? At present only one planet have been clearly detected around a resolved disk in Epsilon Eridani(Greaves et al. 2005) 2) are these disks failed planetary disks ? 3) are these disks left over debris of incomplete planetary formation ? 4) are hidden planets producing the observed warps and assymmetries, gaps or rings ? 5) why they are longlived structures ? what maintain their dynamical stability ? is that due to a special configuration of dust maintained in resonances and what is the role of eventual planets ? 6) when DD evolution begins ? 8 Myr following de la Reza et al. 2005

4. Motivation COROT can in principle detect for the first time the passage of dust structures or planets in unresolved Debris Disks candidates.

5. -- Epsilon Eridani distance 3.2 pc SpT K2V 0.8 Msun Planet 1 : Eps Eri b Semimajor axis 3.3 AU Mass : 0.86 M Jupiter Method : Radial Velocities Planet 2 : Eps Eri c Unconfirmed Mass : 0.1 M Jupiter Method : Dust ring morphology Semimajor axis 40 AU 850 microns. 450 microns. Superposed black squares suggested BG features

6. AU Mic (Liu et al. 2004)

7. Beta Pic

8. (Lecavelier et al. 1997)

9. (Lecavelier et al. 1997)

10. (Lamers et al. 1997)

11. (Lamers et al. 1997)

12. (Lamers et al. 1997)

13. (Galland et al. 2005)

14. BD+31643 - 2Myr B 1-HR4796 - 8Myr 2 – Bpic - 11Myr 3 – AB Aur - 4Myr 4 – HD32297 - ? 5 – Fomahault - 200Myr 6 – Vega - 300Myr A 4 1 (1 5 3 2 AeBe – HD141569 - 5Myr 6 G 1 – HD107146 - 300Myr 2 – Tau Cet - 10Gyr K Epsilon Eridani- 850Myr 2 M Au Mic - 11Myr

15. 60 - 25 25 -12

16. Conclusions Up to the present only one planet has been discovered in a resolved Debris Disk star (Epsilon Eridani). One in a non resolved Debris Disk star (55 Cranc) CoRoT can in principle discover some new cases and give an important insight on studies of the evolution of Debris Disks and on planetary formation. The only problem is the difficulty to find targets for 11<V<14 M type DD candidates are in general M giants We are now looking for hot B/A/F stars with IR excesses.