Novae and Supernovae

A nova is a "new star" only in that it may have suddenly become visible in the sky; in actuality, it is in the late stages of stellar evolution. The name indicates that this fact has been recognized only in modern times. A nova candidate is typically a white dwarf component in a binary star system; its destiny is to violently expel material thrust on it by its companion star. The evolution of the companion of the

Figure 5.19. The winter sky showing Sirius and Betelgeuse near the horizon: (a) Short exposure, Calgary, December 25, 1987, at ~5 a.m. Photo by E.F. Milone. (b) Simulation with TheSky software; red stars appear dark. (c) A deeper exposure, showing many fainter (and redder) stars, but at higher altitude. Photo courtesy of Tammy Dugan of Calgary.

Figure 5.19. The winter sky showing Sirius and Betelgeuse near the horizon: (a) Short exposure, Calgary, December 25, 1987, at ~5 a.m. Photo by E.F. Milone. (b) Simulation with TheSky software; red stars appear dark. (c) A deeper exposure, showing many fainter (and redder) stars, but at higher altitude. Photo courtesy of Tammy Dugan of Calgary.

Table 5.10. A sample of the brighter

novae.

0 0

Post a comment