Celestial river parts lovers
By Vernon Whetstone
When you look at the night sky and see the constellations you are familiar with and know the stories behind them, did you ever stop to consider that someone on the other side of our planet may be looking at the same constellation but have a different story for it?
Let’s take, for example, the Big Dipper. We see it as a dipper, but from the Native Americans we get the idea of “The Great Bear.”
From our English and European ancestors those seven stars were called, the Plough, or the Cleaver, or the Wagon. To the Hindu astronomers they were Sapta Rishi, or the Seven Great Sages.
From some African cultures we get the term, the Drinking Gourd. Hence when fleeing slaves wanted to go north they coined the phrase, “Follow the Drinking Gourd” since those stars were always in the north.
I recently read in the One Minute Astronomer (oneminuteastronomer.com), written by Brian Ventrudo, a story which has its base in ancient Chinese astronomy. The story is about two stars; Vega, representing the humble weaver girl, and Altair as the poor herd boy.
The two were so overcome by their attraction for each other, they were neglecting their duties. So their heavenly masters placed them on the opposite sides of the Celestial River (the Milky Way). However, someone had compassion on them and provided that once a year, on the seventh day of the seventh moon, they could be together when a flock of magpies formed a bridge across the river.
That festival is still celebrated in China as the Qi Xi festival, a major summer event.
Vega, of course, is the brightest star in the constellation Lyra, the Harp. It is located about 25-light years away. A planet-forming ring of dust and debris has been discovered around it with the possibility of a Jupiter-sized planet hiding in the ring.
It is the fifth brightest star in the sky and the second brightest star north of the equator.
One interesting note for Vega, in 12,000 B.C. it was the North Star. Due to the process of precession—the wobble of Earth on its axis—it will be near the northern point in our sky again in 13,700 A.D.
Altair is the brightest star in Aquila, the Eagle. It is about 16-light years away. It has almost twice the mass of our sun and is 11 times brighter.
To find our heavenly lovers, be outside an hour after local sunset looking east. Almost directly overhead, Vega will usually be the first star to pop out of the still partially lit sky followed soon after by slightly dimmer Altair to its lower right.
When the sky becomes very dark, then look for the Milky Way, the celestial river, which is preventing them from being together. Except on the seventh night of the seventh moon, that is July if you haven’t figured that out.
SKY WATCH: First quarter moon, Monday, July 15. For the rest of this week, and into the next, follow the moon each evening as it traverses the sky meeting with several astronomical objects along the way.
Tonight, July 10, an almost three-day old moon will be to the lower left of the bright planet Venus. It will be a good time to look for earthshine. Thursday evening, July 11, the moon has moved on to be near Regulus, the brightest star in Leo, the Lion, and by Monday, July 15, it is near Spica in Virgo, the Maiden.
On July 16, Saturn and the moon are close and on, Thursday, July 18, Antares in Scorpius has a visit from the moon. It will be good practice to follow the moon each evening, because next week we are going to look for the moon in the daytime.
NEXT WEEK: The moon in the daytime sky and more astronomical blather.