Radial-Velocity Survey of Central Stars of Southern Planetary Nebulae .
Makaleler > Tam Makale · 2005
Yazarlar: Melike AFŞAR, Howard E. Bond
Memorie della Societa Astronomica Italiana, Uluslararası, 2005, cilt 76, ss 608-
Özet
We have monitored selected southern-hemisphere planetary-nebula nuclei (PNNi) in order to search for radial-velocity (RV) variations. The observations have been carried out regularly since early 2003 with the SMARTS Consortium 1.5-m telescope and Cassegrain spectrograph at Cerro Tololo Inter-American Observatory, Chile. This study is a followup to an earlier survey of northern PNNi made by De Marco et al. (2004), which suggested that there is a high incidence of RV variability among PNNi. If the variations are due to motion in binary orbits, the fraction of close binaries among PNNi must be very high, suggesting that most planetary nebulae are ejected through binary-star processes, such as common-envelope interactions. We presente here the results of the southern portion of our RV survey. Preliminary results indicate that the fraction of variable RVs is also very high among southern PNNi.