Using the Matariki star cluster as a context for learning can cover many different subjects.
There are about a thousand stars in Matariki (also known as the Pleiades), but only about seven are visible to the unaided eye:
- Alcyone – Matariki, eyes of Tāwhirimātea
- Atlas – Tupu-ā-rangi, sky tohunga
- Electra – Waipuna-ā-rangi, sky spring
- Taygeta – Waitī, sweet water
- Pleione – Tupu-ā-nuku, Earth tohunga
- Merope – Ururangi, entry to the heavens
- Maia – Waitā, sprinkle of water
The relatively young ‘teenage’ stars were born together in a nebula at about the same time. They are much larger than our Sun and are blue because they are hot. Blue stars are the hottest, yellow are medium hot and red stars are at the cooler end of the spectrum.
The hazy white light around the stars that can be seen with a telescope was thought to be the remnants of the nebula the stars came from. However, scientists have discovered that the stars are a little too old to still have remains of the molecular cloud. The hazy light connecting the stars together is a nebula the stars are passing through – the Merope nebula.
The Pleiades is one of the nearest star clusters to Earth – it’s just 444.2 light years away. The distance to the Pleiades is used by astronomers as a marker to help calculate distances to other stars. However, measuring the distance has not been without controversy with two different mechanisms measuring two different measurements. Read more in this article: Resolving the Pleiades distance problem.
Matariki is celebrated on the day of the first crescent moon after the reappearance of Matariki, which is why it isn’t on the same day every year. Matariki is visible almost all year, except for right before the Matariki festival starts. This is because, from our perspective on Earth, Matariki is behind the Sun.
Matariki is used to reset the Maori calendar, which is a lunar calendar. The cycle of the Moon around Earth is different to the cycle of Earth around the Sun. The Moon cycle is around 11 days shorter than the solar cycle, meaning that, after 12 months, there is still about 11 days until Earth returns to the same position in its orbit. Stars can be used to reset the lunar calendar because they are in the same place in the sky at the same time in Earth’s orbit.
Matariki is visible in many locations so has lots of names across different cultures. The Greek name is the Pleiades, in Japan it is called Subaru and in China it is Mao, the Hairy Head of the White Tiger of the West.
Māori ancestors possessed a wealth of astronomical knowledge that they referred to as tātai arorangi. Maori use the stars and moon as a calendar with each phase of the Moon indicating the favourable times for planting, fishing or eeling.
After Matariki, the star cluster gets easier to see as it rises earlier and earlier in the morning, then later and later at night. The cluster can be found by looking north-east after the festival of Matariki – find Orion’s Belt and follow the three stars across the sky to the left until you find Matariki. Once you find it the first time, you’ll always be able to spot it because of its distinctive grouping. This makes it a great class stargazing exercise.
This article has been written by Stardome Observatory and Planetarium, which has been operating since 1967. It is a place of exploration, research and sharing of knowledge and hosts New Zealand’s first and still largest planetarium theatre. Stardome Observatory and Planetarium celebrates its 50th anniversary in 2017.