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The ecliptic circle is the circle on
a celestial sphere around which
the Sun seemingly travels,
making one circuit per year.
The ecliptic circle is marked with
the 12 signs of the Zodiac,
and each sign is divided into 30 degrees, of which
only some of the graduations are usually indicated.
On the astrolabes displayed here,
it has been necessary to abbreviate the names of the signs.
The full names are:
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Aries, Taurus, Gemini,
Cancer, Leo, Virgo,
Libra, Scorpio, Sagitarius,
Capricorn, Aquarius and Pisces.
The Sun's position
The Sun's position on the ecliptic circle
can be found by first determining
its current position in the Zodiac
using the calendar/Zodiac scales
on the back of an astrolabe.
On a conventional astrolabe,
the position of the Sun on the rete can then be found
by finding this position on the Zodiac scale
marked along the ecliptic circle of the rete.
If the rete has been rotated
according to the current time and date,
the position of
this point on the ecliptic circle
can be found amidst the almucantars and elevation arcs,
so that you can find
the precise position of the Sun in the sky.
To minimise the time taken to find
the position of the Sun on the rete,
there is a menu entry which allows
the scale on the ecliptic circle of the rete to show the date:
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Menu: Astrolabe /Rete - Ecliptic circle /Calendar scale
This scale was included on some astrolabes.
The position of the current date along that scale
shows the position of the Sun on that day.
Otherwise,
the approximate position of the Sun
can be found by taking
the point on the ecliptic circle
which is aligned with the present date on the rete,
but there is a slight error in doing this.
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