Jets, Disks, and Cavities: The Protoplanetary Zoo in 2006
C. Grady
Coronagraphic Imaging Surveys
• On-going effort to obtain coronagraphic imagery with supporting narrow-band coronagraphic imagery (GFP), FUV spectra (FUSE, HST), x-ray data (Chandra)
• Goal is to understand, for more isolated systesm at what point central clearing is remotely detectable.
Jets and Accretion
• Now have 6, optically visible Herbig Ae stars with jets or HH knots
• Detection fraction is similar to T Tauri stars
• Age range spans 0.7-7 Myr
• None seen in the ZAMS objects
Disks with Central Dust Deficits• 4 Herbig Ae Stars• 4 T Tauri stars• Herbig Ae stars include one object with comet-
like dust (HD 100546), and 3 lacking warm silicate emission.
• HD 100546 has no jet, and possesses an eccentric 13 AU radius cavity. Is this typical?
• The 4 stars have been modelled as ZAMS objects, but a potentially related one (HD 141569 A) is more correctly a factor of 2 (5 Myr) younger. Is this typical?
HD 169142• A5Ve star (in the optical),
A8Ve (in the UV) at d=145 pc
• Abundant mm dust emission, with disk imaged to 1.6” (230 AU; Dent et al. 2005; Raman et al. 2006)
• 13° inclination (Raman et al. 2006)
• v sin i=55 (Dunkin et al. 1997), implying that veq=240 km/s - later A-type analog of Vega (Aufdenberg 2005)
Disk in NIR Scattered Light
• Disk is azimuthally symmetric• NICMOS traces disk to 1.3”• Radial surface brightness goes as r-3 , implying
r-1.
HD 169142 Visit 1 HD 169142 Visit 2 PSF-PSF
The Environment
• Unlike HD 100546, HD 169142 has an object 8” SW of the Herbig Ae star with NIR colors appropriate for an M Star.
• Object is an H emitter (GFP data).
HD 169142B
• Companion is common proper motion since 1980s, and is M2.5Ve.
Age Estimate
• Companion is double as seen by HST.
• Using F110W magnitudes, d=145 pc, and Teff from the optical spectra, we can locate the brighter star in the HR diagram: coeval with HR 4796 A, at about 8± 4 Myr.
Conclusions and Speculations• All 4 stars (HD 100546, HD 135344, HD 139614, and HD
169142) have veq>200 km/s.• Two of the 4 (HD 135344, Thi et al. 2001; HD 169142, this
study) have estimated ages in the 8-16 Myr range. The other 2 are ZAMS from their location in the HR diagram.
• Central clearing in these systems seems to be a process which occurs comparatively late in the history of the disk. For HD 100546 a second body is implicated (Grady et al. 2005) , despite the underabundance of iron and siderophiles in both the star and the infalling material (Grady et al. 1997).
• May have stumbled onto a population of planetary systems with architechtures which differ from the bulk of the extra-solar systems. Astrometric follow-up is needed (SIM), as is higher angular resolution imagery.