The Pleiades star cluster tonight

[usonian]

15. I drive 6 of them around with me.

Why only 6 and not 7, when some charts say 9?
Well, there over a thousand stars in the cluster.
Just an accounting matter?



https://jalopnik.com/physicists-finally-have-an-answer-for-why-the-subaru-lo-1845985025

One has been drifting close to another.

Careful measurements with the Gaia space telescope and others show the stars of the Pleiades are slowly moving in the sky. One star, Pleione, is now so close to the star Atlas they look like a single star to the naked eye.

But if we take what we know about the movement of the stars and rewind 100,000 years, Pleione was further from Atlas and would have been easily visible to the naked eye. So 100,000 years ago, most people really would have seen seven stars in the cluster.

We believe this movement of the stars can help to explain two puzzles: the similarity of Greek and Aboriginal stories about these stars, and the fact so many cultures call the cluster “seven sisters” even though we only see six stars today.

YMMV (your magnitudes may vary)