Astronomy – Many names for Matariki

This is the season of Matariki – the start of the traditional Maori and Polynesian new year. In astronomy, this group of stars brings with it a lot of surprises.

Matariki is known by many other names around the world: Pleiades, Seven Sisters, Messier 45, M45, Krittika, Subaru, The Hairy Head of the White Tiger and Mul Mul, to name just a few.

The earliest known depiction of Matariki is on a 1600 BC bronze disk known as the Nebra Sky Disk. It is also mentioned in texts from nearly every ancient culture around the globe.

Matariki is an open star cluster and is located in the constellation of Taurus. It is one of the closest star clusters to us – a mere 444 light years away. This means that the light we see now left the stars during the reign of Queen Elizabeth I.

All stars in the cluster are all about the same age, having all been born out of the same dust cloud. They are quite ‘young’ – around 100 million years old. This is around the Cretaceous period, when Tyrannosaurus Rex, Triceratops and Velociraptor roamed the earth.  This makes the Matariki cluster younger than our planet!

Astronomers estimate that Matariki will last for about another 250 million years, before gravitational forces from nearby objects disperses the stars.

When we observe Matariki, most people can see seven, eight or nine bright stars in the cluster. If conditions are excellent, and the viewer’s eyesight is good, you may see up to 14 stars. So how many stars are actually in the Matariki cluster? To date, there are over 1000 confirmed members. Most are small, dim, red stars and a number of ‘failed stars’ known as brown dwarfs. It is very difficult to see these, even with a large telescope. The dominant stars we can see are large, hot, blue stars.

When looking at Matariki through binoculars, or a telescope, we can often see the glow of a nebula around the bright stars. This is known as ‘reflection nebula’ where the light of the star is reflected off surrounding dust clouds. Astronomers originally thought that this dust was left over from the formation of the cluster, however, we now know that it is not even related to the cluster. The cluster is merely travelling through a particularly dusty part of space.

Matariki can now be seen in the early morning sky, about an hour or so before sunrise. You will need a clear view of the horizon to the North East.

By November, Matariki will be seen in the early evening, which is more suitable for those who don’t like getting up early on a winter’s morning.

Remember to use the astronomy apps on your smart phone to help you find it.

The Hibiscus Coast Astronomical Society meets every first and third Thursday of the month at the Faithfull Funeral Services Hall, 35 Red Beach Road at 7:30pm. All are welcome.