Precession

The gravitational pulls of the Sun and the Moon on the Earth's equatorial bulge causes the Earth's axis to sweep out, ecliptic plane ("lunisolar precession").


Globe from Wikipedia, the free encyclopedia

A consequence of the precession of the Earth's axis is that the celestial polestrace out circles in the sky over 25800 years. About 13000 years from now, the nearest bright star to the north celestial pole will be Vega rather than polaris.

Polaris will reach the point at which it comes closest to aligning with the North Pole axis of our Earth in the year A.D. 2102, computed by my Precession and Proper Motion Applet


Declin
RA
2000.0
89° 15' 50.8''
2h 31min 49.08s
2102.4
89° 32' 25.96'
5h 59min 58.5s

2000 Jan 01, Field of view: 5°
2005 Jan 01, Field of view: 5°
2000 Jan 01, Field of view: 68°
13000 Jan 01, Field of view: 68°

by John Walker. Images produced by Your Sky are in the public domain and may be used in any manner without permission, restriction, attribution, or compensation.

Position of Vega (computed by my Precession and Proper Motion Applet):

 

Watch animation

Precession from J2000 to J3000:

Image by my Sky Precession Applet

Change of RA in seconds from 2000 to 2010:

RA / h


0 h
2 h
4 h
6 h
8 h
10 h
12 h
14 h
16 h
18 h
20 h
22 h
Dec
0°
30.75
30.75
30.75
30.75
30.75
30.75
30.75
30.75
30.75
30.75
30.75
30.75
Dec
10°
30.75
31.93
32.80
33.11
32.79
31.92
30.75
29.57
28.71
28.39
28.71
29.57
Dec
20°
30.76
33.19
34.97
35.61
34.96
33.17
30.75
28.321
26.54
25.89
26.54
28.32
Dec
30°
30.76
34.62
37.44
38.46
37.42
34.60
30.74
26.89
24.07
23.04
24.07
26.90
Dec
40°
30.76
36.37
40.47
41.96
40.45
36.34
30.74
25.14
21.04
19.54
21.04
25.15
Dec
50°
30.77
38.74
44.59
46.67
44.52
38.69
30.73
22.78
16.96
14.83
16.96
22.79
Dec
60°
30.78
42.34
50.83
53.89
50.76
42.28
30.72
19.18
10.71
7.61
10.70
19.18
Dec
70°
30.79
49.19
62.61
67.46
62.48
49.03
30.71
12.40
-1.02
-5.96
-1.07
12.39
Dec
80°
30.84
68.90
96.60
106.53
96.15
68.38
30.67
-7.03
-34.73
-45.03
-35.01
-7.25

Change of declination from 2000 to 2010:

RA
0 h
2 h
4 h
6 h
8 h
10 h
12 h
14 h
16 h
18 h
20 h
22 h


3' 20''
2' 53''
1' 40''
-0.2''
-1'40''
-2'54''
-3'20''
-2'53''

-1'40''

0'0.2''
1'40''
2'54''
 

 

Web Links

The Platonic Year

Changes of Celestial Coordinates

Demonstration der Präzession (Animation)

Precession (From Wikipedia, the free encyclopedia)

Präzession und Nutation

Precession

© 2003-2004 J. Giesen

Updated: 2003 Sep 28