Intel's Ronler Acres Plant

Silicon Forest
If the type is too small, Ctrl+ is your friend

Sunday, April 10, 2011

Andromeda Galaxy

I'm reading Marilyn's column in Parade Magazine this morning and she mentions that the Andromeda Galaxy is one of the few objects outside of our own galaxy that is visible to the naked eye. Huh. I remember doing some calculations when I was a kid that said it should appear to be as big as a dinner plate held at arm's length. So I check and according to Wikipedia it "it appears more than six times as wide as the full Moon", so my original calculations were at least somewhere in the ball park. I've never seen the thing, so I can't personal vouch for this.

wikiHow has a page explaining how to locate it. It seems to be near the equator, so prime viewing from the Northern hemisphere is about over, and it will be easier to see from the Southern hemisphere for the next six months. But since it's close to the border you should be able to see it regardless. Also, it's not going to look like a dinner plate. To the naked eye it will just look like a star, but with a telescope, the big smear that it is becomes visible. Or so they say.

Wikipedia gives the apparent dimensions of Andromeda at 190' x 60', which looks like the dimensions of a barn. NED (NASA/IPAC EXTRAGALACTIC DATABASE) clears that up. Besides indicating feet in architectural drawings, the apostrophe is also used to indicate minutes of arc (I knew that, I had just never seen anyone actually use it that way). 190' at 60 minutes per degree is a tad over three degrees. Your thumb held up at arms length is about one degee, so while it's not as big as a dinner plate, the whole smear of Andromeda should be noticable.

No comments: