Fwd: Solar Coordinate Calculation (well one of them!)

2009-09-23 Thread patrick_powers
Hi Jim, I cannot really help you other than to say that the following are the coefficients for a 9th order polynomial which calculates in decimals of a minute the Equation of Time at Noon for each day in 2010 (not a leap year) where x is the serial number of the day ie Jan1 is 1 and Dec

sunset/sunrise times

2009-09-23 Thread Th. Taudin Chabot
All programs that calculate the sunrise/sunset times use an eye height of 0m. Many take the refraction in their calculations. But what is the effect of a normal eye height of 1.5 m when the observer is standing at sealevel like the beach. And when the eye height is even considerabel higher

Lichtuhr

2009-09-23 Thread Peter Kunath
Dear friends, days are getting shorter. May I recommend you the ?Lichtuhr?, vulgo ?light-watch? or an unusal indoor-sundial? www.lichtuhr,de Point to english version and the second screen ?design? and ?3D-animation?. I own a CD with further details and I try to get the permission of the

RE: sunset/sunrise times

2009-09-23 Thread Tom Kreyche
The Explanatory Supplement to the Astronomical Almanac has several separate and extensive discussions on this topic, in particular section 9.33 in the 1992 edition, page 487. A small portion of the section is: At sunrise and sunset the apparent altitude of the upper limb on the horizon is zero

AW: Lichtuhr

2009-09-23 Thread Reinhold Kriegler
An indoor-sundial??? Good Lord! There is only a Black Forest cuckoo missing or a Big Ben striking mechanism … Just in case you want to try a real indoor- reflex-sundial, try the little YouTube film below! * ** *** * ** *** Reinhold R. Kriegler Lat. 53° 6' 52,6 Nord; Long.

exact time of 2009 Autumn equinox

2009-09-23 Thread Jos Kint
Hello Roger Bailey, According to the United States Naval Observatory ( http://aa.usno.navy.mil/data/docs/EarthSeasons.php) the 2009 equinox falls on sept 22 at 21:18:00 UT. This is 61 minutes different from your value. Who is right? Jos Kint Eeuwfeestlaan 38 9840 De Pinte Tel: 09.282.57.61

Re: Solor Coordinate Calculation

2009-09-23 Thread Edley McKnight
Hi James, Dialists, Not exactly the polynomials, but ICE (Interactive Computer Ephemeris) from the Naval Observatory originally, is still available and covers up to 2047. It is freeware and now public domain. It is available from a number of places. It is a DOS program and the latest

Re: exact time of 2009 Autumn equinox

2009-09-23 Thread Frank King
Dear Jos, You raise an interesting point... According to the United States Naval Observatory ... the 2009 equinox falls on sept 22 at 21:18:00 UT. This is 61 minutes different from your value. Who is right? I would use the USNO time myself but your question isn't as easy as it seems...

Re: exact time of 2009 Autumn equinox

2009-09-23 Thread Roger Bailey
I am wrong. I quoted the time listed in the RASC Observers Guide wrong. They list 21:19 UT. Close enough for sundials. Regards, Roger From: Jos Kint Sent: Wednesday, September 23, 2009 11:29 AM To: sundial@uni-koeln.de Subject: exact time of 2009 Autumn equinox Hello Roger Bailey,

RE: Equinox and Equatorial Rings

2009-09-23 Thread John Carmichael
I agree. I have a polar dial with an equinox line and I see this every equinox. It's not that subtle. You can see it easily over just a few hours. -Original Message- From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Frank King Sent: Wednesday,