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Martin Beech 《Astrophysics and Space Science》1986,122(1):57-61
We perform a Monte Carlo analysis of the eclipse probabilities of short-period binary systems in an attempt to estimate the distribution of ellipsoidal variable system with Main-Sequence components. Our results suggest that possibly as many as one in four of the non-eclipsing, spectroscopic binaries withP(d)10, and Main-Sequence components withM
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10 could be ellipsoidal variable systems. This result, while an upper limit, would seem to hold irrespective of primary spectral type (B5 to G5). 相似文献
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Martin Beech 《Astrophysics and Space Science》1985,114(2):345-350
In the standard cosmological model symmetry breaking in grand unified theories will occur at times 10–39 s after the initial singularity when the Universe has cooled to a temperature 1016 GeV. We investigate here whether it is possible for a uniform, large-scale, magnetic field present in the early universe to delay significantly the time at which symmetry breaking occurs. Given the present magnitude of the intergalactic B-field (10–11–10–9 G) it is found that no significant effects are introduced. 相似文献
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Martin Beech 《Monthly notices of the Royal Astronomical Society》2001,326(3):937-942
Some 5 per cent of bright meteors show rapid, quasi-periodic brightness variations. It is argued that this effect, observationally known as flickering, is a manifestation of the rotational modulation of surface mass loss through ablation of a non-spherical meteoroid. We develop a set of time-dependent, single-body ablation equations that include the effect of cross-section area modulation. We present a discussion of the effects that the rotation of a non-spherical meteoroid has on the resultant meteor light curve, and we look in depth at the data related to the fireball associated with the fall of the Innisfree meteorite. We find that the parent object to the Innisfree meteorite was spinning at a rotation frequency of 2.5 Hz when it encountered the Earth's upper atmosphere. We also find that the Innisfree parent body had an initial mass of about 20 kg and that the ratio of its semiminor and semimajor axes was about 0.5. 相似文献
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Martin Beech 《Earth, Moon, and Planets》1988,43(2):187-194
In this article we attempt to trace the development of contemporary meteor science from C. 1830 to C. 1960. From its new beginnings in the early 1830's, the subject saw its most dramatic growth and development in those years surrounding the turn of the 19th century. While the period between C. 1910 to C. 1930 saw a decline in its greater interest, the period between C. 1920 to C. 1950 saw the science enter a stage of consolidation. Around the mid 1950's a stand-off between the theory of meteor ablation and observations arose forcing a re-evaluation of the meteoroid model. These recent developments in meteor studies would suggest that the science is mature in the sense described by Thomas Kuhn. 相似文献
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Martin Beech 《Astrophysics and Space Science》1987,133(1):193-195
We have used the catalogue of dark nebulae compiled by Lynds (1962) to investigate the geometrical nature of the darkest, opacity class 5 to 6, clouds. There would appear to be some evidence that these objects are fractals of dimensionD=1.4. 相似文献
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Martin Beech 《Earth, Moon, and Planets》1988,40(2):213-216
It is argued here that unless antimatter meteors can be shown to possess some unambiguously unique characteristic not displayed by ordinary koinomatter meteors, it will be difficult to infer their existence given the standard interpretation of meteoroid structure. It is also argued, however, that the existence of antimatter meteors is extremely unlikely. 相似文献
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Martin Beech 《Astrophysics and Space Science》1987,139(1):149-153
We consider the mass-luminosity relation proposed for the Wolf-Rayet stars on the basis of detailed numerical models. It is found that the linear form of this relation can be explained in a straight-forward manner and is due to essentially three factors, (i) the WR stars are approximately chemically homogenous, (ii) the stars evolve under constant radiation pressure, and (iii) the stars evolve with high mass loss. 相似文献
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