Will the declination or right ascension of a star ever change?

- Advertisement -

Why / why not?

- Advertisement -
Notify of
Most Voted
Newest Oldest
Inline Feedbacks
View all comments
Geoff G

Yes,in fact they are constantly changing. The reason is precession of the eqinoxes, the slight wobble in the Earth’s axis over a 26,000 year period. RA and Dec must always be at a specified epoch, the one currently being used being 2000.0.

tick tock

Plus they all have “proper motion”, so they wander… some hardly at all, some quite a bit, with Barnard’s Star being the big mover.

Rude Dog

the sun changes ra/dec position all the time!


To obtain a system with horizontal and vertical coordinates of our spherical sky, we always take the movement of our star sky due to earth’s rotation. We first have to look what the celestial north pole is (the elongated direction of earth’s axis, and all stars seem to turn around it), then we can also draw a celestial equator (shall be parallel with earth’s equator)
But yes, like Geoff says, the direction of earth’s axis changes. So after a long time we have new celestial poles and a new celestial equator. That is why the position of stars also shall take other values for the Right Ascension and Declination in our invented coordinate system.


psychic mediums? they claim to beable to talk to the dead?

well if that true then why not ask these dead people what its like on the other side, why not ask them if they...

If the definition of the 'Buddha' is the 'Awakened One' then what are we awakened to?

Please no circular logic such as "We are awakened to the inner state of Buddhahood" or "We are awakened to the fact that we...

In Your Opinion, What is the Difference Between Prayer, Meditation, & Self-Hypnosis?

I'd like to know your opinion of the difference between these 3 activities. Please don't offer dictionary definitions, but rather your own thoughts,...

Who else believes impregnating your subconciousmind?

Who else believes impregnating your subconscious mind with desirable thoughts can bring desirable effects? ALREADY FEELING AND ACTING AND BELIEVING SOMETHING CAN BRING IT ABOUT....

wiccans/pagans only please!?

what kind of things do you put in your "Book of Shadows" i'm starting one but i'm having some trouble with it puting the...
Would love your thoughts, please comment.x