| 11. |
- Malmberg, Daniel, et al.
(författare)
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Is our Sun a Singleton?
- 2008
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Ingår i: Proceedings of the International Astronomical Union. ; 246, s. 273-274
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Konferensbidrag (refereegranskat)
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| 12. |
- Malmberg, Daniel, et al.
(författare)
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The instability of planetary systems in binaries: how the Kozai mechanism leads to strong planet-planet interactions
- 2007
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 1365-2966 .- 1745-3925 .- 1745-3933. ; 377:1, s. 1-4
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Tidskriftsartikel (refereegranskat)abstract
- In this Letter we consider the evolution of a planetary system around a star inside a wide binary. We simulate numerically the evolution of the planetary orbits for both coplanar and highly inclined systems. We find that the Kozai mechanism operates in the latter case. This produces a highly eccentric outer planet the orbit of which crosses those of some of the inner planets. Strong planet-planet interactions then follow, resulting in the ejection of one or more planets. We note that planetary systems resembling our Solar system, formed around single stars in stellar clusters, may exchange into binaries and thus will be vulnerable to planet stripping. This process will reduce the number of Solar system-like planetary systems, and may produce at least some of the observed extrasolar planets.
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| 13. |
- Malmberg, Daniel, et al.
(författare)
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The Singleton Fraction of Stars Formed in Stellar Clusters
- 2008
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Ingår i: Extreme Solar Systems (Astronomical Society of the Pacific Conference Series). - 9781583816660 - 9781583816677 ; 398, s. 75-76
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Konferensbidrag (refereegranskat)abstract
- Most stars form in some sort of stellar cluster or association. In such clusters the number density of stars can be very high. Thus, single stars in such clusters may undergo frequent close encounters with other stars and exchange encounters with binary systems. The perturbation caused by the other star in a close encounter or by the companion star in a binary can have significant effects on the evolution of any planetary system around the initially single star. If the planetary system which formed around the single star was originally solar-system-like, planet-planet interactions, induced by the perturbation from other stars, may change it significantly and leave it more like some of the planetary systems which are observed around other stars. Only if the host star of an initially solar-system-like planetary system never undergoes any encounters with other stars and is never exchanged into a binary may the planetary system remain solar-system like. We define such a star to be a SINGLETON.
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| 14. |
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| 15. |
- Shaw, M, et al.
(författare)
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The brain monitoring with information technology (BrainIT) collaborative network : data validation results
- 2009
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Ingår i: Acta Neurochirurgica Supplements. - Vienna : Springer Vienna. - 9783211855775 - 9783211855782 ; , s. 217-221
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Background The BrainIT group works collaboratively on developing standards for collection and analyses of data from brain injured patients towards providing a more efficient infrastructure for assessing new health technology. Materials and methods Over a 2 year period, core dataset data (grouped by nine categories) were collected from 200 head-injured patients by local nursing staff. Data were uploaded by the BrainIT web and random samples of received data were selected automatically by computer for validation by data validation (DV) research nurse staff against gold standard sources held in the local centre. Validated data was compared with original data sent and percentage error rates calculated by data category. Findings Comparisons, 19,461, were made in proportion to the size of the data received with the largest number checked in laboratory data (5,667) and the least in the surgery data (567). Error rates were generally less than or equal to 6%, the exception being the surgery data class where an unacceptably high error rate of 34% was found. Conclusions The BrainIT core dataset (with the exception of the surgery classification) is feasible and accurate to collect. The surgery classification needs to be revised.
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