Loading...
Please wait, while we are loading the content...
The dust properties of hot r coronae borealis stars and a wolf-rayet central star of a planetary nebula: in search of the missing link
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Nordhaus, J. Roman-Duval, J. Misselt, K. A. Matsuura, M. Meixner, M. Sonneborn, G. Camp, K. A. Freeman, W. R. Lawson, W. A. Meade, M. Babler, B. Clayton, Geoffrey C. De Marco, O. Speck, A. K. Gallagher, J. S. Wolff, M. J. Whitney, B. A. |
| Copyright Year | 2012 |
| Description | We present new Spitzer IIRS spectra of two hot R Coronae Borealis (RCB) stars, one in the Galaxy,V348 Sgr, and one lying in the Large Magellanic Cloud, HV 2671. These two objects constitute a link between the RCB stars and the [WCL] class of central stars of planetary nebula (CSPNe) that has little or no hydrogen in their atmospheres such as CPD -560 8032. HV 2671 and V348 Sgr are members of a rare subclass that has significantly higher effective temperatures than most RCB stars, but sharing the traits of hydrogen deficiency and dust formation that define the cooler RCB stars. The [WC] CSPNe star, CPD -560 8032, displays evidence for dual-dust chemistry showing both PAHs and crystalline silicates in its mid-IR spectrum. HV 2671 shows strong PAH emission but shows no sign of having crystalline silicates. The spectrum of V348 Sgr is very different from those of CPD -56deg 8032 and HV 2671. The PAH emission seen strongly in the other two stars is only weakly present. Instead, the spectrum is dominated by a broad emission centered at about 8.5 microns. This feature is not identified with either PAHs or silicates. Several other novae and post-asymptotic giant branch stars show similar features in their IR spectra. The mid-IR spectrum of CPD -56deg 8032 shows emission features associated with C60 . The other two stars do not show evidence for C60. The nature of the dust around these stars does not help us in establishing further links that may indicate a common origin. |
| File Size | 934605 |
| Page Count | 19 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20120009504 |
| Archival Resource Key | ark:/13960/t0ps2s68r |
| Language | English |
| Publisher Date | 2012-01-01 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Hydrogen Display Devices Novae Planetary Nebulae Crystallinity Silicates Asymptotic Giant Branch Stars Magellanic Clouds Hot Stars Polycyclic Aromatic Hydrocarbons Wolf-rayet Stars Infrared Radiation R Coronae Borealis Stars Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
