Night Sky Photography -- 04-01-2020 -- The Constellation Gemini, First Quarter Moon, & Winter Circle

Good evening fellow stargazers!

 

My apologies for not having any night sky photography since February, but March here in South Carolina is pretty cloudy and rainy for the most part. In a way that is a good thing since it helps to wash away the mountains of allergy-inducing POLLEN, but bad because it caused me to miss out on several really awesome heavenly shows. 

 

This evening -- with thankfully clear skies at last! -- I was able to capture some good shots of our beautiful Luna in all her half-lit first quarter phase glory in the vicinity of Castor and Pollux, the two brightest stars in the constellation Gemini the Twins.

 

The first shot here shows the two main stars of the Twins above and to the right of Luna. 

 

 

Interesting to note that while Castor appears as a bright pinpoint of light, in reality it’s actually a small system made up of three pairs of binary stars -- six stars centered in a single mass. The two larger visible components in the Castor system are hot, A-type stars. The smaller components are cool, M-type red dwarf stars. In total the mass of all six stars together is about six times that of our sun.

 

This was the first binary system that was recognized in 1802 by the astronomer Frederick William Herschel. 

 

Pollux is slightly brighter than Castor. It shines with a golden glow while Castor appears whiter. Pollux is the 18th brightest star in Earth’s night sky. 

 

In 2006, astronomers discovered a exo-planet orbiting Pollux they named Thestias (Pollux b). The planet is estimated to have at least twice the mass of Jupiter.

 

Despite being "twins" both Pollux and Castor are actually about 18 light-years apart on a cosmic scale. At 34 light-years, Pollux is closer to us while Castor is a further 52 light-years away. Thus Pollux and Castor aren’t bound, but only near each other from our Earthly perspective. Castor and Pollux are about 4.5 degrees apart in the night sky, which helps stargazers estimate separation distances between other stars.

 

According to Greek mythology and stargazer lore, the twins Castor and Pollux were the sons of a mortal mother, Queen Leda; Castor was the mortal brother, born from a mortal father, King Tyndareus of Sparta, while Pollux, a son of Zeus, was the immortal brother. When Castor was later slain in a battle by his cousin Idas (who was then killed instantly by Zeus with a thunderbolt), Pollux was inconsolable and was given the choice by Zeus of spending all his time on Mount Olympus, or giving half his immortality to his mortal brother. He begged Zeus to relieve him of his immortality opting for the latter, thus enabling the twins to alternate between Olympus and Hades. Zeus granted his request, and Pollux and Castor stand reunited in the heavens as a tribute to the power of brotherly love. 

 

The second shot I took is a wide shot of the Twins and was able to just barely get all of the major stars of the Constellation Gemini in the shot. As an added bonus I also managed to get just about all of the major stars that make up the Winter Circle (Winter Hexagon) and the Winter Triangle as well. The only one missing star is Rigel, on the bottom leg of the Constellation Orion, which was below the horizon. 

 

  

Finally, my last photo for the evening is a close-up of the beautiful First Quarter Moon. 

 

 

The reason this moon phase is called a first quarter because it is one quarter of the way around in its orbit of Earth, as measured from one new moon to the next. Although a first quarter moon appears half-lit to us, leading to the erroneous term "half-moon" the illuminated portion we see of a first quarter moon truly is just a quarter of the moon's diameter. We’re now seeing half the moon’s day side, that is. We never see the other side (or "dark side") of the moon, so in reality all we ever see is half-a-moon during a full moon. 

 

During the first quarter moon, the right side of the moon is lit, while the left side of the moon is lit during the last quarter moon later in the month as the moon travels eastward in the skydome. 

 

Well folks, I hope y'all enjoyed my night sky offerings for the evening. My hope is for clearer skies as spring gets up and running and more night sky photography in the coming weeks. Venus will be beginning its conjunction with the Pleiades Star Cluster on the evening of April 3rd. Be sure to check it out, I will try to get some shots -- God and good weather permitting. 

From South Carolina, have a wonderful Dixie evening and keep your eyes to the night skies, y'all!