The Celestial Sphere from Latitude 45° North

1700 Hours Sidereal Time

The sky from 45°N at 1700 hours sidereal time

This page contains a description of the stars, constellations, and deep-sky objects that can be seen in the sky at around 1700 hours sidereal time. It is assumed that the observer is located at approximately 45° latitude north.

To use the sky map, orient it so that the direction you are facing is at the bottom of the map. Zenith, the point directly overhead in the sky, is located at the centre of the map.

Looking North

The W-shaped constellation low in the northern sky is Cassiopeia. Above her is her husband Cepheus. Around to the east, the flying horse Pegasus is rising, chasing Cygnus or the 'Northern Cross' high into the sky. The brightest star of Cygnus is Deneb which marks the tail of the swan (or the top of the cross). Albireo, the star at the opposite end of Cygnus from Deneb is actually a binary. Seen through binoculars, it splits into two stars of contrasting colours.

Leo is setting in the west. Above the lion is Ursa Major. Often known as the 'Big Dipper', it appears to be hanging from its handle. Examine the star marking the bend in the handle. This is Mizar. On a dark night, it should be possible to see its faint companion Alcor. The two stars at the end of the bowl of the dipper point eastwards to Polaris, brightest star of Ursa Minor. Polaris currently marks the approximate position of the north celestial pole; thus, all of the stars in the sky appear to rotate about this second magnitude star. Winding its way between Ursa Major and Ursa Minor is the dragon Draco, its 'lozenge'-shaped head keeping a close eye on the bright star Vega.

Looking South

The 'Summer Triangle' of Deneb, Vega and Altair is getting higher and higher in the sky. Vega is the bright bluish star in Lyra and Altair is the brightest star in the constellation Aquila. Just to the east of the 'Summer Triangle' is the small but easily-seen kite-shaped constellation of the dolphin called Delphinus.

High overhead is the constellation of Hercules. On the western edge of the 'Keystone' can be found the Great Globular Cluster, M13. To the naked eye it appears as a faint smudge but is actually a spherical cluster of hundreds of elderly stars. Continuing westward, the half-circle of Corona Borealis is located just beyond Hercules. Boötes is the next constellation along. Shaped like a kite or ice cream cone, Arcturus marks its base. The bright star low in the southwest is Spica in the zodiacal constellation Virgo.

Due south and very low can be found brighter members of the zodiac. Scorpius just clears the horizon. Bright red Antares marks the heart of the scorpion. Antares means the 'rival of Mars' (or Ares) and is so-named because of its red appearance, much like the planet Mars. Following Scorpius across the sky is Sagittarius which resembles a teapot.