Sunday, November 8, 2009

Alcyone Star in Pleiades

I remembered something about Alcyone. I checked online maybe 5 or so years ago about Alcyone that it is multiple star. I somehow contacted a man somewhere. Guess what? He responded back with negative comment. He said it is not orbiting, whateverso... I couldn't believe what I read from him. I knew I'm right but why was he trying to mess it up for?

Today, I decided to look up what they has on Alcyone and found this:

Alcyone (eta Tauri) is a significant example of a nearby multiple star. It is a giant star of more than 10 Solar masses and is almost a thousand times more luminous than the Sun. It is orbited by 3 faint companion stars. The entire cluster contains numerous double stars and a few triples.

Also found this part:

Alycone is actually a multiple star system. The primary, Alcyone A, is an eclipsing binary, consisting of two giant B stars with a separation of about 0.031 arc-seconds (roughly the distance of Jupiter from the Sun). The high rotational speed of Alcyone A – over 200 km/s (more than 100 times faster than the Sun) – has caused gas to spin from its equator into a surrounding light-emitting disk. This makes Alcyone A a Be star but with a disk thicker than usual. The binary Alcyone A is orbited by three companions. Alcyone B and Alcyone C are both 8th magnitude white, main sequence A stars and are separated from A by 117 and 181 arcseconds, respectively. Alcyone C is a Delta Scuti star whose brightness varies from magnitude +8.25 to +8.30 with a period of 1.13 hours. Alcyone D is a yellow-white main sequence F star, with an apparent magnitude of +8.7, separated by 191 arcseconds from the primary.

I always knew but I have no way of explaining what it is like. That is not only thing... I also knew of brown dwarf in there too. I somehow found out about it few years ago. I wasn't imagine things. It is a fact.

I thought why not find an old photo of Pleiades to compare with currently photo.

I found few things... very few stars seemly moved. Mmm... 100 years has passed. I thought it is so interesting!