Archive for August 21, 2014

08/21/2014 – Ephemeris – What do a dolphin, an arrow and a coffin have in common?

August 21, 2014 Comments off

Ephemeris for Thursday, August 21st.  The sun rises at 6:52.  It’ll be up for 13 hours and 46 minutes, setting at 8:38.   The moon, half way from last quarter to new, will rise at 4:12 tomorrow morning.

Located below the eastern edge of the Summer Triangle of three of the brightest stars in the sky, which is high in the southeast in the sky at 10 p.m., is the tiny constellation of Delphinus the dolphin.  Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water.  The parallelogram itself has the name Job’s Coffin.  The origin of this asterism or informal constellation is unknown.  Of the dolphin itself: the ancient Greeks appreciated this aquatic mammal as we do, and told stories of dolphins rescuing shipwrecked sailors.  There’s another tiny and slender constellation to the right of Delphinus called Sagitta the arrow, which is said to represent Cupid’s dart.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.


Delphinus, Sagitta and the Coat hanger. Diagram created using Stellarium.

Delphinus, Sagitta and the Coat hanger. Diagram created using Stellarium.

The Coat hanger is strictly a binocular asterism.  However it was discovered by the great Arabian astronomer Al Sufi inn the 10th century, and is currently designated Collinder 399.  It is actually a random pattern of unrelated stars.

Constellation figures

Delphinus and Sagitta images along with the stars and constellations of the Summer Triangle. Created using Stellarium.