منابع مشابه
Have Mirror Planets Been Observed?
Over the last few years, several close orbiting (∼ 0.05 AU) large mass planets (M ∼ M Jupiter) of nearby stars have been discovered. Their existence has been inferred from tiny doppler shifts in the light from the star. We suggest that these planets may be made of mirror matter. We also suggest that some stars such as our sun may also have a similar amount of mirror matter, which has escaped de...
متن کاملHave protoplanetary discs formed planets
It has recently been noted that many discs around T Tauri stars appear to comprise only a few Jupiter masses of gas and dust. Using millimetre surveys of discs within six local star formation regions, we confirm this result, and find that only a few per cent of young stars have enough circumstellar material to build gas giant planets, in standard core accretion models. Since the frequency of ob...
متن کاملThe Host Stars of Extrasolar Planets Have Normal Lithium Abundances
The lithium abundances of planet-harbouring stars have been compared with those of open clusters and field stars. Young (chromospherically active) and subgiant stars have been eliminated from the comparison because they are at different stages of evolution and Li processing to the planet-harbouring stars, and hence have systematically higher Li abundances. The analysis showed that the Li abunda...
متن کاملWhat Fraction of Sun-like Stars Have Planets?
The radial velocities of 1800 nearby Sun-like stars are currently being monitored by eight high-sensitivity Doppler exoplanet surveys. Approximately 90 of these stars have been found to host exoplanets massive enough to be detectable. Thus, at least 5% of target stars possess planets. If we limit our analysis to target stars that have been monitored the longest ( 15 years), 11% possess planets....
متن کاملA New Family of Planets? “ocean-planets”
A new family of planets is considered which is in between the rocky terrestrial planets and the gaseous giants, “Ocean-Planets”. We present the possible formation, composition and internal structure of these putative planets. We consider their oceans, as well as their possible exobiology interest. These exoplanets should be detectable by Space missions such as Eddington, Kepler, and possibly CO...
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ژورنال
عنوان ژورنال: Journal of Public Health
سال: 2014
ISSN: 1741-3842,1741-3850
DOI: 10.1093/pubmed/fdu036