The Astronomical Units
نویسندگان
چکیده
The IAU-1976 System of astronomical constants includes three astronomical units (i.e. for time, mass and length). This paper reports on the status of the astronomical unit of length (ua) and mass (MSun) within the context of the recent IAU Resolutions on reference systems and the use of modern observations in the solar system. We especially look at a possible re-definition of the ua as an astronomical unit of length defined trough a fixed relation to the SI metre by a defining number.
منابع مشابه
Maraghe Observatory and an Effort towards Retrieval of Architectural Design of Astronomical Units
Maraghe observatory was built by such engineers as Moayiededdin Orozi etc. under supervision of Khaje Nasireddin Tousi in 7th century AH. The most significant feature associated with Maraghe observatory is the fact that architecture is employed to achieve astronomical purposes in this site. The reason for preferring observatory by astronomers was the fact that these units are superior to wooden...
متن کاملA Comparative Study of the Astronomical Revolution and Astronomy in the Safavid Period
The science of astronomy in Iran, like some other places in the world, has a long history. According to the internal accounts and the travelogues of the European tourists, astronomy was one of the most noted sciences for the Safavid government, and was influential in all affairs including governmental and military affairs, celebrations, and mourning ceremonies. This study uses a descriptive-ana...
متن کاملShabnumā-wa-Rūznumā A Rare Astronomical Instrument Extant in Two Specimens
In India, there are extant two nineteenth century specimens of an otherwise unknown astronomical instrument called Shabnum?-wa-R?znum? with which observations can be done both in the day and at night. While the R?znum? is nothing but a sine/horary quadrant, the Shabnum? appears to be inspired by the Sanskrit instrument Dhruvabhrama-yantra which was invented by Padman?bha in the first quarter of...
متن کاملRFI mitigation in the context of Pulsar coherent de-dispersion at Nancay radio astronomical Observatory
Radio astronomical pulsar observations require specific instrumentation and dedicated signal processing to cope with the dispersion caused by the interstellar medium. Moreover, the quality of observations can be limited by radio frequency interferences (RFI) generated by Telecommunications activity. This paper will present the innovative pulsar instrumentation based on Graphical Processing Unit...
متن کاملSilicon molecules in space and in the laboratory
Despite the highly non-volatile nature of Si, silicon bearing molecules are a significant trace constituent of the gas associated with late-type stars and star forming regions, representing nearly 10% of the molecular species that have been identified in space. The early astronomical detection of SiO and its remarkable maser emission stimulated laboratory studies of other small silicon species ...
متن کامل