Every Halloween – and a few days before and after – the brilliant star Arcturus sets at the same time and on the same spot on the west-northwest horizon as the summer sun.
What’s more, this star rises at the same time and at the same place on the east-northeast horizon that the sun does during the dog days of summer.
That’s why – every year at this time – you can consider Arcturus as a “ghost” of the sun.
Halloween – also known as All Hallows’ Eve or All Saints’ Eve – is observed in various countries on October 31, especially in the United States. It’s a big deal for America children, who roam from house to house trick or treating, hoping for candy and other treats. This modern holiday is based on a much older tradition, that of cross-quarter days.
It’s fun to associate the star Arcturus with this time of year.
If you live in the Southern Hemisphere, however, you can’t see Arcturus right now. South of the equator, Arcturus sets at the same time and on the same place on the horizon as the winter sun. In other words, Arcturus sets before the sun and rises after the sun at southerly latitudes at this time of year.
At mid-northern latitudes, Arcturus now sets about 2 hours after sunset and rises about 2 hours before sunrise.
By watching this star in the October evening chill, you can envision the absent summer sun radiating its extra hours of sunlight. Not till after dark does this star set, an echo of long summer afternoons. Similarly, Arcturus rises in the east before dawn, a phantom reminder of early morning daybreaks.
You can verify that you’re looking at Arcturus once the Big Dipper comes out. Its handle always points to Arcturus.
By the way, if you live as far north as Barrow, Alaska, the star Arcturus shines all night long, mimicking the midnight sun of summer.