North and South Galactic Poles – Coordinates on our Celestial Sphere

Au printemps, nous pouvons observer des galaxies à l’extérieur et au-delà de la Voie Lactée, car nous levons les yeux et sortons du plan du disque galactique. En fait, nous pouvons voir l’emplacement du pôle nord galactique. Au primptemps Le pôle nord galactique n’est pas loin de notre nuage vedette Coma Star à Coma Berenices.

stellarium-006Pôle Nord de Notre Galaxie dans notre ciel du printemps

Even though we are so far North of our Celestial Equator … Can we see the South Galactic Pole in Autumn as the Earth  orbits along the path of the planets?

In short the answer is Yes.

Given our latitude of 48 degrees, and the inclination of the plane of the galaxy to our orbital plane,  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 +27°.4 Coma Berenices
south pole (−90° latitude) 0h 49m −27.4° Sculptor

stellarium-004

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 18:45PM mid-November, 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 ( -31 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

 

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