The Case of the Missing Pleiad

Once upon a time (if memory serves) there was a discussion on saa
concerning the missing Pleiad.

Back in the days before beef stew (or somewhat more recently) the
average eye, on an average night, could see 6 naked eye stars in the
Pleiades star cluster. Since this cluster was also referred to as the
*Seven Sisters*; there was speculation concerning the fate of the
missing Pleiad.

In my own experience, either 6 or 9 of the named stars can be seen
with the naked eye. If conditions are good enough to see 7, I'll also
see two more.

Fast forward to today. I recently read about the Pleiades in yet
another book. An illustration showed the 9 brightest stars along with
their names. The text pointed out the seven sisters as well as the
two parents. At that point a thought crossed my mind.

On those nights when I could see 9 stars I was seeing the seven
sisters and the two parents. Might it be that before the
proliferation of outdoor lighting, on a good night, the average
observer could see the nine named stars? Might it also be that those
observers were aware of the distinction between the seven sisters and
the two parents? If so, when they spoke of seeing seven Pleiades they
were referring only to the sisters since the parents, though present
and visible, were not sisters. Might this clear up the case of the
(not so) missing Pleiad?

Willie R. Meghar