It's also important to remember that the Pleiades we see today is the Pleiades of ~400 years ago, not to mention the game takes place 1000 years from now. While stars don't change much in that span of time usually, some celestial events do occur pretty quickly.
Yeah, as RedWizzard said, the information in game is often based on current day information rather than the date it was set, which is why I keep wondering if there is any relevance in that particular difference.
And if the Pleiades has been a hotbed of alien activity throughout history as suggested by the lore, one could assume that nearly anything is possible in this region of space.
This part is kind of why I'm interested in the difference though.
Some of my thoughts on it are that the UAs:
1. Somehow "cloaking" something in the vicinity of of Merope (including some of the dust cloud
2. Worried the dusctcloud is leaving this area and reseeding it (through hyperspace, obviously, based distances involved)
3. Feeding from the dust in that region and depleting it (same thing as 2)
Of course, it could still be the vision of the cloud enhanced and adjusted to remove the glare as I said before.
EDIT: This video talks about some astronomers who were looking at the first pulsar, and even though they knew it was a natural source of radio emissions, they named it LGM-1, or Little Green Men. A quick look at the galaxy map reveals that this pulsar is in game, and accurately named. It is 9,126ly from where I am in Azaleach. This video also brings up that golden disk NASA made that has a pulsar reference map to our sun.
http://www.universetoday.com/25376/pulsars/
Interesting you should mention LGM-1 (which I remember learning about it at uni many years ago - did some Astronomy based courses as part of Physics degree that I never completed), in fact it is more officially referred to as PSR B1919+21, PSR J1919+21, PSR 1919+21, or other variations on today...
and
the site states that:
The trajectory of the principal gas cloud forming the Pleiades nebulae can be traced back to an origin in Gould's Belt some 15 Million years ago, in a blowout of gas from an exploding star (PSR 1919+21) into the Galactic halo.
Which sounds to me as if it's saying the supernova that formed LGM-1 is responsible for the dust cloud in the Pleiades...though I haven't seen that information stated anywhere else.
Out of interest, I visited LGM-1 last September (before I was even aware of the above site, or even the UAs) and it was rather disappointing. There is only the neutron star in system and nothing else (EDIT, misremebered, there is actually a class-g star in system too having checked the map again).
The article also piqued my interest in the Gould Belt (
https://en.wikipedia.org/wiki/Gould_Belt). Apparently Gould belt is responsible for most of the young bright star clusters (particularly OB grouping) in the local region of the galaxy, and in many searches the Pleiades are mentioned in relation. However, one (and I'm going to have to look it up again now) said that the Pleiades star cluster is not actually related because it is too old (but this is the cluster rather than the cloud).