scholarly journals ASTROLABE; INSTRUMEN ASTRONOMI KLASIK DAN KONTRIBUSINYA DALAM HISAB RUKYAT

ELFALAKY ◽  
2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Fathor Rausi
Keyword(s):  
Solar Time

AbstrakKontribusi Astrolabe sebagai instrumen astronomi klasik tidak boleh dipandang sebelah mata. Peran dan kontribusinya cukup signifikan dalam perkembangan astronomi. Astrolabe secara umum berfungsi untuk menentukan waktu surya (solar time) dengan memanfaatkan fenomena alam, yaitu Matahari pada siang hari dan pengamatan bintang pada malam hari. Kehadiran Astrolabe dengan fungsinya tersebut sangat membantu aktivitas manusia sehari-hari dalam beberapa lini. Astrolabe mengalami modifikasi di tangan umat Islam, karena fungsi instrumen klasik ini selaras dengan syariat Islam, khususnya dalam penentuan awal waktu salat. Masuknya waktu salat dalam hukum Islam didasarkan kepada fenomena alam, seperti tergelincirnya Matahari (zawāl) sebagai tanda masuknya waktu salat zuhur. Kata Kunci: Astrolabe, instrumen astronomi klasik dan hisab rukyat.    

scholarly journals SeMiner: A Flexible Sequence Miner Method to Forecast Solar Time Series

Information ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Sérgio Díscola Junior ◽  
José Cecatto ◽  
Márcio Merino Fernandes ◽  
Marcela Xavier Ribeiro
Keyword(s):  
Time Series ◽  
Solar Time

scholarly journals Stellar Irradiance Variations

2001 ◽  
Vol 203 ◽  
pp. 78-85
Author(s):  
R. R. Radick
Keyword(s):  
Time Series ◽  
Solar Variability ◽  
The Sun ◽  
Solar Time ◽  
Total Irradiance ◽  
Average Activity ◽  
Current Behavior

The variability of several dozen stars similar to the Sun in mass, age, and average activity has been monitored regularly in chromospheric Ca II HK emission for over three decades, and photometrically for over fifteen years. Larger samples have been observed less comprehensively. Analogous solar time series exist. A comparison of solar variability with its stellar analogs indicates that the Sun's current behavior is not unusual among sunlike stars. Both solar models and stellar measurements suggest that a true luminosity variation underlies the cyclic total irradiance changes observed on the Sun.

VARIATIONS IN SOLAR TIME OF EXTENSIVE AIR SHOWERS

1961 ◽  
Vol 39 (6) ◽  
pp. 935-940
Author(s):  
B. G. Wilson ◽  
J. G. G. Dionne ◽  
F. Terentiuk
Keyword(s):  
Electron Density ◽  
Extensive Air Showers ◽  
High Electron ◽  
High Electron Density ◽  
Air Showers ◽  
Solar Time ◽  
Wide Range

150,000 extensive air showers of high electron density have been recorded at an altitude of 2283 meters. Analysis of the data in solar time for a wide range of densities shows no evidence for the large semidiurnal variations previously reported by other groups. A possible explanation of this difference may lie in the different methods of selecting the showers.

scholarly journals XVI. An occultation of Aldebaran by the Moon, Dec. 12. 1738. P. M. observed in Fleetstreet with a reflecting Telescope of 15 inches in Length, by Mr. G. Graham, F. R. S

1740 ◽  
Vol 41 (459) ◽  
pp. 632-632
Keyword(s):  
The Moon ◽  
Solar Time ◽  
The Mean

The Occultation at Emerged at Duration The Sun's Transit at Noon at 11 h . 59'. 52". the Clock gaining of the mean Solar Time about One Second in a Day.

A Solar Time Classification for Meteorological Use

1958 ◽  
Vol 39 (11) ◽  
pp. 569-573 ◽  
Author(s):  
Irving A. Singer ◽  
Gilbert S. Raynor
Keyword(s):  
Diurnal Cycle ◽  
Wind Profile ◽  
Meteorological Data ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Temperature Data ◽  
Lapse Rate ◽  
Time System ◽  
Meteorological Tower ◽  
Solar Time

In order to effect a more consistent grouping of hourly meteorological data influenced by the diurnal cycle, a chronology based on the time of sunrise and sunset was devised. A code classified all hours within each bi-weekly period by this time system. The classification was further extended by dividing the year into solar seasons, defined as periods of time during which the distribution of solar hours is uniform. The use of solar time as a major classification in the analysis of two years of hourly wind and temperature data obtained from six levels on the 420-ft meteorological tower at Brookhaven National Laboratory resulted in a better understanding of the relationships between the variables than could have been obtained by the use of standard time. Results of several lapse-rate and wind-profile studies made using both standard and solar time demonstrated the advantage of the latter system. Application of this method to other problems and regions is discussed.

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