analemma2

SUN’s Position Data for the Following Date, Time and Location

Universal Time:
1/5/2008 16:16:54 Local Time:
1/5/2008 1:16:54 PM Julian Day: 2454588.17840 Sidereal Time:
2h 39m 50.0s Location: Avonport, Canada Latitude: 45° 6.46' N Longitude: 64° 13.6' W
Sun is in constellation: ARIES, the Ram. Sunrise: 6:05:26 AM
Noon Transit: 1:14:06 PM(True Solar Noon, when Sun crosses the Meridian at its highest altitude for the day) Sun is crossing the Meridian 2 min48 sec early (fast), ( Correction to the sundial is minus 2 min 48 sec to give Mean Solar Time (the correction is now increasing).
Noon Altitude: 59° 23.4’( it was about 54° 33.5'Apr16th, a 2 week gain of about 5°)
Sunset: 8:23:19 PM
For places in the Northern Hemisphere of Earth, Sun is now above the horizon for more than 14 hours. At latitude 45°N, the solar day is about 14 h 18 min. Sun’s RA: 2h 36.9m Dec: +15° 19.9'
Sun is north of the Celestial Equator. The Sun in about 6 weeks will reach its maximum altitude, marking the Summer Solstice in the Northern Hemisphere. Sun’s distance from Earth:
1.0078 AU or about 150764734.9 km Apr 16th the distance was 150 155 871.6 km, For the next 2.5 months we are actually moving further away from the Sun.

For a photo and other data about today’s Sun click here.
The green dots represent change in the Sun’s position during a period of 7 days. Studying the spacing of dots, one can see that the weekly, therefore daily, rate of change in the Sun’s pattern is greatest when it is near the Celestial Equator (the red line on the diagram). Change slows as the Sun’s position approaches the top and bottom of the analemma. The fine green line is the ecliptic. The red arrow represents change mostly due to Earth’s tilted axis shifting relative to the Sun. The blue arrow represents change due to Earth moving around the Sun in its orbit.

See the current distribution of DAY and NIGHT on EARTH go to this site and and click “Show Earth views”

SUN on the ANALEMMA (yellow dot) as it was for

May 1, 2008 at 13:16:54 ADT ( click here to go to June 6th analemma ]

(Mean Solar Noon at Horton Bluff - near Avonport, N.S.)

What is an ANALEMMA? (click on the diagram)

THE ANALEMMA AT YOUR LOCATION: When compared to Horton Bluff, what would be the same? The shape, size and location of the analemma and the Sun, relative to the starry background, would be essentially about the same, however, the altitude of everything in the diagram view, relative to your horizon, would shift upward if your latitude is south of Horton Bluff (45° 6.46' N ) or shift downward if you are north of H.B. The shift would be the difference in our latitudes. What would be different?

Another way to arrive at the altitude position: the altitude of the Celestial equator above your south horizon would be 90° minus your latitude. For example if your latitude was 40°N, then 90° - 40° = 50°. The celestial equator would cross the meridian 50° above your south point; the whole celestial sphere would shift accordingly.

The time at which the Sun would cross the meridian (transit) depends on the longitude of your meridian compared to the Prime Meridian (0° longitude). At a time given for the Sun’s transit at the Prime Meridian, one must make allowances for the time it takes Earth to turn sufficiently to bring the Sun across your meridian. Earth turns (rotates) through 1° every 4 minutes, therefore, allow 4 minutes for every 1° of longitude you are east or west from the Prime Meridian.

North Americans are west of the Prime Meridian, therefore, to get the time that the Sun will cross a western meridian, allow 4 minutes to be added on (+) for each degree of west longitude.

For example, if the Sun transits the Prime Meridian at 11:58:30 UT, when will it cross the meridian at longitude 64.2° W (nearly the longitude of Horton Bluff)? 64.2° X 4 min = 256.8 min = 4.28 h

= 4 h 16 min 48 sec later.

The transit time at 64.2°W would be 16:15:18 UT. Converted to the local Time Zone of Horton Bluff (ADT is 3h earlier than UT) 16:15:18 UT = 13:15:18 ADT or 1:15:18 P.M. So, the place must be slightly east of Horton Bluff, if on the same day Sun crosses HB’s meridian at 1:15:24 P.M.

Somewhere in all of this you may sense that the analemma has some kind of kinship with GPS.

The Sun is our nearest star and the central figure in our solar system. With a mass 330000 times that of Earth, the Sun contains almost 1000 times more matter than all of the other objects in the solar system put together. As stars go, the Sun is slightly larger and hotter than the 'average' star, which would have a mass about 1/2 that of the Sun. By composition, the Sun is about 75% hydrogen, 25% helium, and mere traces of other elements. Today’s Sun