Caption: Sky map for the North Pole sky on the winter solstice at midnight. Click on the image to get square polar-sky pdf sky map which is NOT for the same time.

Features:

1. The horizon is the circumscribing circle.

2. Since we are at the North Pole (90° north latitude), the celestial equator coincides with the horizon.

3. Also since we are at the North Pole, we are in the middle of the 6-month night.

4. The equatorial coordinate right ascension (RA) increases going east along the celestial equator from its zero point vernal equinox. The vernal equinox is both the point where ecliptic crosses the celestial equator and also the event when the Sun traveling along the ecliptic crosses the celestial equator.

5. The vernal equinox happens on about Mar21.

6. Right ascension is given in the funny angle units of hours: 1 hour = 15°.

7. The equatorial coordinate declination (Dec) is measured from the celestial equator along great circles that pass through the north celestial pole (NCP) and south celestial pole (SCP).

8. Because we are the North Pole, the NCP is at zenith.

9. The ecliptic is the curve crossing the lower part of the sky map.

   The ecliptic is the path of the Sun on the sky. The Sun completes the path in one solar year.

10. The ecliptic coordinate system longitude (which is measured along the ecliptic itself as shown) is also measured from the vernal equinox going eastward, but in degrees.