How Far Apart Are The Stars Of The Pleiades

[ToraToraTora]

Been trying to find this out but I've had no luck, anyone any ideas?

[jim360]

Not able to find an answer myself very easily. The full cluster (of about 1000 stars) seems to be spread out over a sphere of about 40 light-years radius, so you could estimate an average distance on that of maybe 8 light years I think.

[bhg481]

A reference book I have says the cluster is about 350 LY away and about 12 LY from end to end. Is that what you mean by "How far apart"?

[Jonathan-Joe]

The Pleiades cluster has low density - circa three stars per cubic parsec on average according to http://www.oasi.org.uk/Obsvns/20021209_POP/20021209_POP.php

[jim360]

Just to address apparent contradictions:

1. It's possible that the number of stars recognised in the cluster has increased since 2002;
2. Different measures of cluster radius are possible -- I deliberately chose the largest, the "tidal radius";
3. I only did a few minutes of research so it's possible I've got hold of the wrong answer. I did arrive at the final figure by estimating rather than a more formal calculation.

The implication from the data in https://en.wikipedia.org/wiki/Pleiades#Brightest_stars is that the stars are fairly separated from each other.

[bhg481]

jim - if you think your data from 2002 might be out-of-date, now is the time for me to admit that mine was taken from a book published in 1957.

[ToraToraTora]

I was just interested in some examples, of distances between some of the 7 sisters really. The cluster is around 430LYs away. I suspect they look close but are probably further apart than we are from our closest star, 4LYs

[jim360]

I thought Jonathan's might be out-of-date, although I'm not saying that it's necessarily wrong because of that, and I don't think that my source should be necessarily preferred.

[ToraToraTora]

ok thanks all for your input

[Atheist]

TTT; forgive my curiosity, but I wonder what inspired your question. Are you by any chance interested in Billy Meier?

[ToraToraTora]

nope never heard of him.

[Old_Geezer]

I thought our nearest star was about 8.3 LM away.

[Gromit]

OG
Everyone knows the sun is 8 light minutes from Earth.

Alpha Centuri, which is 3 stars is 4.2 light years from the sun.

[Naheed]

This gravitationally driven cluster of numerous stars appears some 430 light-years distant, and these sibling stars drift through space mutually at about 40 km/sec.