Eastern Dawn Sky in June 2023

This chart is intended for skywatchers who want to find the Matariki/Pleiades star cluster in the dawn sky.

The Matariki/Pleiades/Subaru cluster is quite faint. So even in a dark sky it has to be well above the horizon before it is visible. It is also easily hidden by twilight, bright moonlight and artificial light. The need for some elevation and not too much twilight means the cluster is hard to see till mid-June.

As the Earth moves around the Sun the Sun appears to move against the background stars. We can't see the stars in the daytime so the movement isn't obvious. What we see is the stars being a little further west each night. Because of the tilt of Earth's axis to its orbit the Sun's track is tilted on the sky. At this time of year the Sun is near its most northern position, our winter solstice.

The Matariki/Pleiades cluster is near the Sun's track so it disappears into the western evening twilight in March as the Sun approaches it. It remains hidden through April and May as the Sun passes it by. It reappears in the eastern dawn sky as the Sun moves east of the cluster, or downward and away in our dawn-sky view. This happens everywhere in the world as the Sun's track is near the cluster.

Because the cluster reappears in mid to late June it makes a good marker for the southern winter solstice, our shortest day.

The planet Mercury/Whiro/Takero appears as a bright ‘star’ to the right of the Matariki cluster on June 15th. Whiro is brighter than all the true stars in the region except Hinetakarua/Sirius. Whiro slips down the sky morning-to-morning and brightens. It disappears in the dawn twilight before the 25th.

The thin crescent Moon will be just above Matariki on the morning of June 16th.

Alan Gilmore 4 April 2023