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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

 

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

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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