The Apparent Right Ascension and Apparent Declination of the Sun Year : 2016
6
Month : 7
Day : 22 6 List Hour
(TT)
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01
02
03
04
05
06
07
08
09
10
11
12
13
14
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16
17
18
19
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22
23
Apparent Right Ascension
h m s
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
08
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08
07
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07
07
08
08
08
08
08
08
09
09
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09
09
09
10
10
10
10
10
10
09
19
29
39
48
58
08
18
28
38
47
57
07
17
27
37
48
58
08
18
28
38
48
58
Apparent Declination
° ' "
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
13
13
12
12
11
11
10
10
09
09
08
07
07
06
06
05
05
04
04
03
03
02
02
01
32
03
34
04
34
04
33
03
32
01
30
59
28
57
26
55
24
54
23
53
23
53
23
53
Notes :
1. Apparent right ascension (RA) and apparent declination (Dec) of the Sun are the astronomical coordinates of the
Sun on the celestial sphere in the equatorial coordinate system. "RA" corresponds to the longitude on the celestial
sphere, measured eastwards along the celestial equator with respect to the zero hour of RA which passes through
the two celestial poles and the vernal equinox point. It is expressed in hours ( h ), minutes ( m ) and seconds ( s ),
and if expressed in terms of angles, 1h=15°, 1m=15', 1s=15". "Dec" corresponds to the latitude on the celestial
sphere, measured north or south of the celestial equator in degrees ( ° ), minutes ( ' ) and seconds ( " ). Declinations
north of the celestial equator are positive, while those to the south are negative.
2. Terrestrial Time (TT) is the time standard used for precise calculation of astronomical events observed from the
geoid. On the geoid, gravitational potential is the same everywhere and the gravitational force is perpendicular to
the geoid. TT is independent of the irregular rotation of the Earth and its relation to the International Atomic Time
(TAI*) is TT = TAI + 32.184 seconds.
*F o r m o r e i n f o r m a t i o n a b o u t T A I , p l e a s e r e f e r t o t h e f o l l o w i n g h y p e r l i n k :
http://www.hko.gov.hk/gts/time/basicterms­TAI.htm