Compositae novae Austro-Americanae. I

Recurrent Novae , Classical Novae , Symbiotic Novae , and Population II

Light curve analysis of decay phase of nova outburst are summarized. Nova duration is determined by the strong wind mass-loss which depends only on the white dwarf mass. Fast novae correspond very massive white dwarfs and very slow novae correspond almost lower mass limit of white dwarfs. This relation is shown in both of classical novae and recurrent novae. Light curves are theoretically repro...

Delays in dwarf novae I: The case of SS Cyg

Using the disc instability model and a simple but physically reasonable model for the X-ray, extreme UV, UV and optical emission of dwarf novae we investigate the time lags observed between the rise to outburst at different wavelengths. We find that for “normal”, i.e. fast-rise outbursts, there is good agreement between the model and observations provided that the disc is truncated at a few whi...

Tgrs Observations of Gamma-ray Lines from Novae. I. Limits on the Positron Annihilation Line in Five Individual Novae

The Transient Gamma Ray Spectrometer (TGRS) on board the WIND spacecraft has spent most of the interval 1995–1997 in a high-altitude orbit where γ-ray backgrounds are low. Its high-resolution Ge spectrometer is thus able to detect weak lines which are slightly offset from stronger background features. One such line is predicted from nucleosynthesis in classical novae, where β-decays on a time-s...

Wood Anatomy of Vernonieae (Compositae)

Systematics of Isocarpha (Compositae: Eupatorieae)

Isocarpha comprises five species ranging from southern Texas and the Bahamas to northern Peru and northeastern Brazil. The genus belongs in Eupatorieae rather than Heliantheae, but structure of the head of Isocarpha with its elongate, chaffy receptacle is anomalous within Eupatorieae. An hypothesis is presented suggesting the evolutionary derivation of this type of head through formation of flo...