posted on Aug, 17 2015 @ 10:22 PM
a reply to: Reallyfolks
Um, you're answering a post that's more than 5 years old. The star you're looking at is Arcturus, which is one of my favorites. It's an old star
which has used-up all the hydrogen in its core and is now burning (nuclear fusion, actually) helium. This has caused it to swell up to ~25 times the
radius of our sun (though its mass is about the same). As it swelled-up, the surface area increased and allowed it to radiate more heat. Thus its
outer surface is much cooler than our sun. This gives it its nice, golden-orange color.
Arcturus a bit of an odd-ball for this neighborhood. Almost every star we can see with our naked eye is rotating around in the disk of our galaxy
like horses on a merry-go-round. Arcturus is diving through the disk of the galaxy at right-angles to the rest of the traffic. This means it is
moving across our sky very fast compared to other stars - which is especially notable because it is ~36 light-years away - not exactly close. Since
Roman times, it has moved more than twice the width of our moon across the sky, which is a lot when compared to nearly every other bright star in our
In Hawai'ian, Arcturus is known as Hōkūle`a, which means "star of gladness". From the islands, it passes straight overhead in the summertime. The
ancient Polynesian mariners would use it as a guide-star: They'd sail north from Tahiti until it was overhead and then look east-west for Hawai'i; if
they could see the Trade Winds disrupted by the tall volcanoes, they knew they were west of the islands. If they didn't see this, they knew they were
to the east.
For me, when I'm walking the dog late at night in the dead of winter, seeing Arcturus rising in the east tells me that spring is not far off. It also
reminds me of a woman I met in the summer of '87...
edit on 17-8-2015 by Saint Exupery because: I corrected something.