Venus the Eight Sister – Quite rare conjunction: There are many objects in the night sky that most people have heard of; The Big Dipper, The North Star, Orion’s Belt and The Seven Sisters to name a few. The night sky is made up of 88 different constellations which we can use to navigate and tell the time of year. The ability to recognise and possibly predict the annual arrival of seasonal constellations are likely to go back to prehistory, but the first and comprehensive catalogue of stars and their positions was made by the Babylonians from around 1000BC.
We use these techniques at the Aurora Borealis Observatory to find which direction we should be looking to see the northern lights. Using the famous Ursa Major constellation we can trace a path across the night sky to the North Star, when you’re looking at the North Star you are facing the direction to observe the northern lights. Learning and joining the dots in the night sky is a wonderfully fun pastime and an activity we will have at the Aurora Borealis Observatory next season.
On Saturday 4th April the Seven Sisters will be joined by the bright planet Venus and temporarily become eight. Why is this happening? As Venus and the Earth orbit the Sun, Venus’ position in our sky changes daily, as does all the other planets. This was noticed by the Ancient Greeks and they were named planētes asters, meaning wandering stars. Because of this quite often in our skies there will be conjunctions of planets and other well known objects along the plain of the ecliptic, the path across the sky which our Sun follows that the planets also follow. Our astronomer Matt says, “One of my most favourite experiences in my astronomy career was observing the Moon and Saturn at the same time through a powerful telescope. On this special conjunction I could see two of my most favourite objects at once, it was magical. I also saw it happen with Jupiter and the Moon a month after that and managed to get a picture.”
The official name of the Seven Sisters is the Pleiades and is Greek in its origin. The Pleiades name is derived from the name of the Greek Mythological mother of the Pleiades, Pleione, which in turn probably means “sailing” or “many/plenty” since she was an Oceanid Nymph. The sailing reference in its name might refer to the Pleiades rising coinciding with fine nautical weather in the Mediterranean. You have probably seen it at some point in your life and wondered what it was, most people have.
The Seven Sisters are an asterism of stars in the constellation of Taurus, when we look up to the night sky, we can find them sitting to the top right of the constellation of Orion in the southern part of the sky. If you use Orion’s Belt and draw a line through it from left to right it will take you up to Taurus and its brightest star Aldebaran, if you continue that you will then find them.
In the northern hemisphere we start to see them rising from the start of October and deep in the middle of the winter they are high up in the south. Using this knowledge, you can predict that the shortest day of the year and the middle of winter is around two months away. These stars are quite far away from the Earth, their distance was calculated by the Hubble Space Telescope to be around 444 light years away!
Venus the Eight Sister conjunction is quite rare compared to others we see, the last one occurred 16 years ago in 2004 and the next great conjunction of them both will take place in 2028. To observe something as bright as Venus next to this beautiful collection of stars is definitely something not to be missed.