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The
solar analemma
Text
and pictures by Anthony AYIOMAMITIS
Appendix
The
next tables list characteristics of the various analemmas
recorded by the author as well as various parameters discussed in
the previous pages of this article.
Dates listed in the
schedule (Table 2) are valid whatever the observer's latitude. Only
angular values of azimuth and altitude (Table 1) change according
the recording location.
Table
1 - Summary of Analemma Characteristics
|
Camera
|
Analemma
(UT)
|
Start/End
Dates
|
Nb
Images
|
Az
Min
|
Az
Max
|
Alt
Min
|
Alt
Max
|
|
Canon
A-1
|
06:00:00
|
12/01/02-21/12/02
|
411
|
83.90°
|
123.48°
|
2.61°
|
32.27°
|
|
Canon
AE-1
|
07:00:00
|
12/01/02-21/12/02
|
43,432
|
92.91°
|
134.04°
|
12.00°
|
44.07°
|
|
|
08:00:00
|
12/01/02-21/12/02
|
432
|
104.27°
|
146.31°
|
20.02°
|
55.68°
|
|
Canon
AE-1
|
09:00:00
10:00:00
|
27/03/02-21/03/03
27/03/02-21/03/03
|
43
43
|
121.92°
155.29°
|
160.75°
177.39°
|
25.57°
28.35°
|
66.44°
74.36°
|
|
Canon
A-1
|
10:28:16
|
12/01/02-21/12/02
|
43,139
|
176.56°
|
186.05°
|
28.58°
|
75.44°
|
|
Canon
AE-1
|
10:28:16
|
12/01/02-21/12/02
|
52
|
176.56°
|
186.05°
|
28.58°
|
75.44°
|
|
Canon
AE-1
Canon
A-1
|
11:00:00
12:00:00
|
12/01/02-21/12/02
06/01/04-20/12/04
|
43
434
|
186.24°
202.53°
|
209.48°
240.48°
|
27.99°
24.53°
|
73.81°
65.37°
|
|
Canon
AE-1
|
13:00:00
14:00:00
|
27/03/02-21/03/03
27/03/02-21/03/03
|
43
43
|
216.53°
228.39°
|
257.13°
268.11°
|
18.44°
10.06°
|
54.41°
42.76°
|
|
Canon
AE-1
|
15:00:00
|
12/01/02-21/12/02
|
413
|
238.61°
|
276.98°
|
0.59°
|
30.96°
|
|
1
Exposures for Jan 12-24 and Dec 21, 2002 not possible due to a total physical obstruction of the solar
disk by a mountain. Supplementary exposure of the partially-obstructed sun
on December taken for illustration purposes.
2
Surimpression problems forced me to record an new analemma in 2003 with a
Canon A-1 body.
3
Exposures for Jan 12, 2002 and Nov 06-Dec 21, 2002 not possible due to a total obstruction of the solar disk by
a mountain. Supplementary multi-exposure of the partially-obstructed sun
on November 2002 taken for illustration purposes.
4
Technical problems with the Canon AE-1 body. All the sequence was repeated in 2004.
Table 2 - Multi-Exposure Schedule
|
|
Jun
21/02
|
|
|
Jul
16/02
|
|
May
28/02
|
|
Jul
26-27/02
|
|
May
17/02
|
|
Aug
04/02
|
|
May
09/02
|
|
Aug
11/02
|
|
May
02/02
|
|
Aug
18/02
|
|
Apr
25/02
|
|
Aug
24/02
|
|
Apr
19/02
|
|
|
Aug
30/02
Apr
12-13/02
|
|
|
Apr
07/02
|
|
Sep
05/02
|
|
Apr
01/02
|
|
Sep
11/02
|
|
Mar
27/02
|
|
Sep
16/02
|
|
Mar
21/02
|
|
Sep
22/02
|
|
Mar
16/02
|
|
Sep
27/02
|
|
Mar
10-11/02
|
|
Oct
03/02
|
|
Mar
05/02
|
|
Oct
08/02
|
|
Feb
27/02
|
|
Oct
14/02
|
|
Feb
21/02
|
|
Oct
20/02
|
|
Feb
15/02
|
|
Oct
26/02
|
|
Feb
09/02
|
|
Nov
01-02/02
|
|
Feb
02/02
|
|
Nov
08-09/02
|
|
Jan
24/02
|
|
Nov
17/02
|
|
Jan
12/02
|
|
Nov
29/02
|
|
|
Dec
21/02
|
|
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Table 3 - Exception Report (Jan 08/02 to Dec 21/02)
|
Date |
Analemma
(UT)
|
Exception
Description
|
|
Jan
01/02
|
All
|
Complete
restart of analemma project (11 analemmas).
|
|
Jan
12/02
|
06:00:00
15:00:00
|
Exposure
of complete (or partial) solar disk not possible due to
obstruction.
|
|
Jan
24/02
|
06:00:00
15:00:00
|
Exposure
of complete or partial solar disk still not possible.
Partially-obstructed
solar disk imaged for illustration purposes
on
originally scheduled date!
|
|
Feb
02/02
|
06:00:00
|
Partially-obstructed
solar disk imaged for illustration purposes
on
originally scheduled date!
|
|
Feb
09/02
|
All
|
Complete
schedule now in effect with no further obstructions.
|
|
Mar
27/02
|
09:00:00
10:00:00
11:00:00
12:00:00
|
Accidental
film advance and complete restart effective next day for double
analemma.
Accidental
film advance and complete restart effective next day for double
analemma.
|
|
Apr
25/02
|
06:00:00
07:00:00
|
Exposure
incorrectly taken at 08:00:00 LMT (in lieu of 09:00:00 LMT) and
digitally removed from final image. Rescheduled for Apr 26/02.
Exposure
incorrectly taken at 09:00:00 LMT (in lieu of 10:00:00 LMT) and
digitally removed in final image. Proper exposure at 10:00:00 LMT
taken on time.
|
|
Nov
29/02
|
15:00:00
|
Last
possible multi-exposure of full solar disk.
|
|
Nov
29/02
|
15:00:00
|
Supplementary
exposure of partially-obstructed solar disk. No further exposures
possible.
|
|
Nov
29/02
|
06:00:00
|
Last
possible multi-exposure of full solar disk.
|
|
Dec
01/02
|
06:00:00
|
Supplementary
exposure of partially-obstructed solar disk. No further exposures
possible.
|
|
Dec
21/02
|
All
|
Completion
of analemma project - tempus fugit!
|
|
Jan 01/03
|
All
|
Complete restart of
uncomplete analemmas
|
|
Table
4 - Analemma Checklist
|
Camera
|
(1)
Confirm aperture setting (f/11)
on Canon A-1
(2)
Confirm shutter speed (1/60th sec)
(3)
Confirm focus set to infinity and view through viewfinder
(4)
Battery check at "T minus 10 min"
(5)
Confirm no light leak from Baader solar filter material
(6)
Confirm firm attachment of camera body to support base
(7)
Engage the multi-exposure switch on the Canon A-1 body
(8)
Lock shutter release after exposure and film "advance"
(9)
Turn battery off after exposure |
|
Timing
|
(1)
Ping to Atomic Clock Server at "T minus 10 min"
(2)
Adjust schedules accordingly due to Daylight Savings Time etc if
not using UT format |
|
Permanent
Mount |
(1)
Confirm stability of mount and firmness of clamps
(2)
Ensure proper placement of camera support base into permanent
mount and confirm there
is no movement
(3)
Cover mount well after use for protection from elements
|
|
Weather
|
(1)
Obtain hourly weather prediction for "T minus 1 day" and
extent of potential clouds and
overcast skies
(2)
Closely monitor weather conditions and clouds for imaging day
(3)
Study movement of sun in azimuth and altitude if exposure is +1
day by necessity due to
possible clouds on the day and time of the scheduled exposure and,
if applicable, adjust
schedule for analemma for other half of loop |
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Project
End
|
(1)
Shoot supplementary frame showing the landscape immediately after the analemma frame
so as to assist the photo lab in properly cutting the negatives
(2)
Prayers to Apollo for fresh chemicals and safe film development
(3)
Contact Dr. Analemma (Dennis di Cicco, via S&T)
(4)
Try to Publish in Sky & Telescope, Astronomy, and optionaly in Sterne und Weltraum,
Astronomy Heute, Man & Stars, Ciel et Espace, APOD, etc.
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