| 释义 |
ˈprotostar Astr.
[f. proto- + star n.1]
A contracting mass of gas in which nucleosynthesis has not yet begun, representing an early stage in the formation of a star.
1954H. Alfvén Orig. Solar Syst. xii. 188 This condensation may have taken place from a ‘protostar’ of the type considered by Spitzer and others. 1972Sci. Amer. Aug. 49/3 It has been suggested that protostars are formed when some of the gas and dust associated with the spiral arms of the galaxy piles up into clouds. 1976[see observationally adv.]. 1977J. Narlikar Struct. Universe ii. 27 Such a cloud contracts as a whole, but subsequently breaks up into smaller subunits or ‘protostars’ when instability develops in the system.
Also protoˈstellar a., of, pertaining to, or being a protostar or protostars.
1973Nature 17 Aug. 425/1 Conditions are therefore appropriate for the formation of solid planets if the nature of the protostellar body is such that dispersal of the particulate matter does not take place soon after its formation. 1975Ibid. 6 Feb. 393/2 The initially low metal abundance could radically alter both the cooling of the gas required for protostellar collapse and the mechanisms which limit the greatest mass which can condense into a star. 1976Astron. Jrnl. LXXXI. 1092/2 There is..a cluster of protostellar objects..southwest of M17 at the apparent edge of fragment B. |