Night Sky Observing – How Far South do we See?

In the Spring time, when we stand outside and observe the constellations,  we can observe galaxies beyond our own because we are looking up and out of the plane of  the galactic disk. In fact we can see the location of the North Galactic Pole. (see planisphere).

The North Galactic Pole is  not far from our featured Coma Star Cloud in Coma Berenices.

annotatedNGPPlanesphere
Planisphere – Spring View showing North Galactic Pole Location

Can we see the South Galactic Pole in Autumn as the Earth proceeds around in its orbit along the path of the planets?

In short the answer is Yes.

Given our latitude of 45 degrees, and the inclination of the plane of the galaxy to our orbital plane, that we should see the South Galactic Pole. Here are the coordinates for the North and South Galactic Pole in Right Ascension and Declination

 Galactic Pole right ascension declination constellation
north pole (+90° latitude) 12h 49m(12h 51.4m) +27°.4(+27°.13) Coma Berenices
south pole (−90° latitude) 0h 49m(0h 51.4m) −27.4°(−27.13°) Sculptor

 

planeofGalaxy

GalacticVsPlanetPlaneImage courtesy http://www.therlen.co.za/blog/wp-content/uploads/2012/09/GalacticVsPlanetPlane.jpg

SouthGPAnnotated
Planisphere in Autumn showing aproximate location of South Galactic Pole

In the Fall, say 11PM mid-Octoher, we can see down to the South Galactic Pole. Above, our planisphere marks the approximate location of the South Galactic Pole just under constellation Cetus the Whale .

Although we can see the South Galactic Pole from our latitude, we cannot see the South Celestial Pole.  For we can only see down to a declination the amount of our co-latitude ( -45 degrees) from the Celestial Equator.

howFarSouth

Here is a southern star map showing the stars in the Southern Constellations that never get above our horizon. Interestingly, there is no equivalent pole star like Polaris to mark the approximation location of the South Celestial Pole.
south_circumpolar_constellations