New Moon Visibility Computation for Bandar Seri Begawan Continue reading “New moon visibility and properties for Ramadan 1438H from Brunei Darussalam”
By MOHAMMAD SH. ODEH, Arab Union for Astronomy and Space Sciences (AUASS), P.O. Box 141568, Amman 11814, Jordan (e-mail: firstname.lastname@example.org) (Received 12 May 2005; accepted 19 September 2005)
Abstract. A new criterion for lunar crescent visibility has been established using 737 observations, almost half of them obtained by the Islamic Crescent Observation Project (ICOP). This criterion is based on two variables, viz. the topocentric arc of vision and the topocentric crescent width. The new model is able to predict the visibility of the lunar crescent both for naked eye and optically aided observations. From the database we found a Danjon limit of 6.4 degrees.
Introduction The lunar crescent visibility has been studied by many astronomers since the Babylonian era, with as a result currently more than 12 different criteria for lunar crescent visibility, based on a number of sightings in different lunar conditions. Many of these criteria were developed by Islamic astronomers, since a number of Islamic religiouseventsaredirectlyrelatedtolunarcrescentsighting.Forexample,thenew Lunar (Hijric) month begins on the next day of sighting the new crescent at west after sunset.
Download HERE New Criterion Crescent.pdf
Present at the observation were Pengiran Shahdani (Vice President II), Awang Hj Mohamad Azri (Exco) and 4 other members.
The result of the observation was submitted to Islamic Crescents’ Observation Project (ICOP). See worldwide observation result here.
Assigned vantage points throughout the country could sight the new moon of Syawal 1432 H. The official announcement of the sighting was also made on TV and Radio and Brunei Darussalam starts Aidilfitri tommorrow, 31 August 2011.
This is a table computed by Her Majesty’s Nautical Almanac Office computes and distributes predictions of lunar crescent visibility for Bandar Seri Begawan, Brunei Darussalam from Year 1980 until 2030.
Visibility Predictions for the New Crescent Moon are catagorised by
A Easily visible
B Visible under perfect conditions
C May need optical aid to find the crescent Moon
D Will need optical aid to find the crescent Moon
E Not visible with a telescope
F Not visible, below the Danjon limit
The first crescent or hilal was visible from this country during the new moon sighting by the Survey Department on July 15. Based on the account, the moon’s altitude was
about 10.465 degrees, elongation of 11.223 degrees and it was 22 hours 33 minutes old at sunset. The visibility based on Mooncalc indicates that on 15th July 2007, the new moon should be easily visible from many parts of the world but ICOP report generalised, Brunei being the first eastern country to sight the new moon crescent.
Congratulation to the moon sighting committees of the Survey Department.
By Louay J. Fatoohi, F. Richard Stephenson & Shetha S. Al-Dargazelli Department of Physics, University of Durham
When the distinguished French astronomer Andre Danjon was the director of Strasbourg Observatory, he became engaged in determining the light curve of the Moon. In 1931 he noticed that the Moon of August 13, which was only 16.2 hr before new, extended only 75-80° from cusp to cusp. In other words, Danjon found that the outer terminator of the crescent was considerably less than a complete half-circle, which it should have been theoretically. This was not an isolated observation because other observations, and also examination of previous records, showed that this shortening of the crescent was a general and real phenomenon. Danjon also noticed that the shortening diminishes as the angular distance of the Moon from the Sun increases.
By Bradley E.Schaefer NASA/Goddard Space Flight Center, Code 661 Greenbelt, MD 20771, USA
Prediction of the first visibility of the lunar crescent is a difficult problem involving astronomy, meteorology, and physiology. Historically, this problem has been attacked by an empirical approach where some set of observations is used to deduce a criterion for visibility. In this paper, I present a list of 201 observations and their observing circumstances for use in deriving and testing prediction algorithms. I find that criteria involving the moonset lagtime and the Moon’s age are quite bad in their predictive ability. Criteria involving the relative altitude and azimuth of the Moon at sunset are better, yet still can yield incorrect predictions within a zone of uncertainty with a width of over 105 degrees in longitude. The new theoretical model of Schaefer ( 1 988) is found to have a zone of uncertainty with an average total width of 47 degrees in longitude.