Dave: Thanks so much Dave for looking that up for me. I can't wait to test it today! Because the declination changes throughout the day, I guess it's not quite true that the sun rises exactly due east and sets due west on the equinox... Is that correct?
John John L. Carmichael Jr. Sundial Sculptures 925 E. Foothills Dr. Tucson Arizona 85718 USA Tel: 520-696-1709 Email: [EMAIL PROTECTED] Website: <http://www.sundialsculptures.com> ----- Original Message ----- From: "Dave Bell" <[EMAIL PROTECTED]> To: "John Carmichael" <[EMAIL PROTECTED]> Sent: Friday, September 21, 2001 10:58 PM Subject: Re: equinox solar declination > Hi, John! > > Per the Dialist's Companion, I find the time of solar declination zero > to be 15:40:03. (I'm using somewhat central Tucson's coordinates as > 32.22N, 110.97W) At 09:00, I get declination = 0.108127 deg (North). > Altitude is 33.679622 deg. I'll have to let you figure where that puts the > nodus shadow! > > Dave > > > On Fri, 21 Sep 2001, John Carmichael wrote: > > > Hi all: > > > > I'm getting this message out a little late, but tomorrow on the > > equinox, I'd like to check the solar declination of the nodus's > > shadow. (Of the Flandrau heliochronometer). I want to see if the > > center of the shadow is centered exactly on the 0 degree line at the > > exact moment of equinox. > > > > My astronomical calendar says that the equinox occurs here (in Tucson > > AZ) at exactly 4:05 pm. But since the declination is changing so > > quickly this time of year, I'm wondering if the shadow will be exactly > > on the 0 dec. line in the morning too. > > > > Does anybody know what the solar declination is at around 9:00 my > > time? (6 hours and 55 minutes before the actual equinox). I wonder > > if I'll be able to detect this small amount? > > > > Thanks > > John > > > > John L. Carmichael Jr. > > Sundial Sculptures > > 925 E. Foothills Dr. > > Tucson Arizona 85718 > > USA > > > > Tel: 520-696-1709 > > Email: [EMAIL PROTECTED] > > Website: <http://www.sundialsculptures.com> > > > >
