THE SOUTHWORTH PLANETARIUM
207-780-4249      www.usm.maine.edu/planet
70 Falmouth Street     Portland, Maine 04103
43.6667° N                   70.2667° W
Founded January 1970
Julian date:  2457669.16

             "The happiest place on planet Earth."

THE DAILY ASTRONOMER

Thursday, October 6, 2016

Fox and Arrow

Envisioning the characters around the constellations is not a task for the faint-hearted.  Most star patterns do not truly resemble whatever creature or object they are meant o represent.  (The adversarial constellations Orion and Scorpius are notable exceptions.)   For this reason, we often encourage sky watchers to seek out shapes and other prominent patterns before they begin to imagine the constellation figures associated with those shapes. 

Today, we're going to point out two small constellations and will understand if you  decide not to bother with the imagination part.    These constellations, called Vulpecula the Fox and Sagitta the Arrow, are literally tucked away inside the Summer Triangle.   Since this triangle is high overhead in the early evening, one could consider early autumn as the best season to find them.   Then again, they are so difficult to see even during the best season. 

​Vulpecula and Sagitta:  The Fox and the Arrow.

Two constellations hidden within the Summer Triangle.   Whereas Sagitta dates back to at least the Greco-Roman era, Vulpecula is of more recent vintage, having been first created by Johannes Hevelius (1611-1687)    One can find them tonight high in the evening sky.  Or, more correctly, one can attempt to find them tonight high in the evening sky.

Just south of Cygnus the Swan, Vulpecula the Fox consists of a few stars in a crooked line arrangement.      Created by acclaimed seventeenth century astronomer/Uranographer Johannes Hevelius (1611-1687), Vulpecula was originally depicted with a goose in his jaw, and so was known as "Vulpecula  cum Anser," (Fox with Goose.)     Even though the goose eventually vanished, the constellations brightest star is named "Anserine," the goose star.

Look out of the fox to find the small constellation Sagitta.    While it is as inconspicuous as Vulpecula, Sagitta is a much older constellation.   Its origin extends back to the Greco-Roman era.     Mythologically, Sagitta represents the arrow that Hercules used on Aquila, the Eagle who gnawed Prometheus' liver.   Prometheus, the best ally humans ever ignored, brought fire to the mortals, much to Zeus' chagrin.  Zeus punished Prometheus in a rather clever and cruel manner.    Prometheus was chained to a rock and condemned to have an eagle gnaw at his liver from dawn to dusk.  At night the liver regrew, only to be devoured by the same eagle the following day. This continued for many years.    Had Hercules not eventually intervened by slaying the eagle and releasing Prometheus, this constant feast-regeneration-feast-regeneration would still be happening today.     The arrow Sagitta rests just above the eagle which was slain by it.

_______________________________________________________________
FROM THE CATACOMBS OF INFINITE KNOWLEDGE

​M27:  "The Dumbbell Nebula"   A planetary nebula in the constellation Vulpecula the Fox.     This nebula is approximately 1,360 light years from Earth.     It formed after a star cast off its outer layers, leaving only a white dwarf behind.  Image: ESO