Stargazing in December

The December skies mark my favourite time of the year for stargazing. Despite the cold weather, the skies promise the best opportunities to see what lies beyond the EarthòÀÙs atmosphere. So pour yourself a hot chocolate, wrap up in warm clothes and head outside to witness the night skyòÀÙs wonders.

If you werenòÀÙt lucky enough to see a meteor in the skies during the previous two months, December will not disappoint. On the 13^th and 14^th of December the Geminids meteor shower will peak with up to 100 meteors per hour. This is the perfect meteor shower for children to glimpse at as it begins between 9pm and 10pm then lasts right through the night and into the early hours of the morning.ˆà ˆàThe GeminidòÀÙs can be seen from anywhere in the world because they happen for up to 24 hours, so wherever you are reading this, mark the 13^th of December in your calendars.

Unlike most meteors showers which are caused by comets, the GeminidòÀÙs originate from an asteroid called 3200 Phaethon. This asteroid poses a mystery to scientists as they believe it could be a òÀØdead comet.òÀÙ 3200 Phaethon has a highly elliptical orbit, similar to that of a comet, however when it nears the sun it doesnòÀÙt produce a tail. ItòÀÙs surface also looks identical to an asteroidòÀÙs, not to mention the pieces that break off which eventually form the beautiful GeminidòÀÙs meteor shower are much denser than a cometòÀÙs dust flakes. To only add to the mystery, scientists canòÀÙt understand fully why the Geminids are so intense, as 3200 Phaethon releases very little debris to explain the large and prolonged meteor shower that graces our December skies.

To see the Geminids in all their glory, head away from any cities and towns and to a place with little to no artificial light. Once you find a comfortable spot, make sure you can see as much of the sky as possible, and in general face south. Also try locating the constellation of Orion which is easy to find in the south western part of the sky and contains some of the skies best features while waiting for your eyes to adjust.

The December skies provide some of the best constellations and who could argue with the infamous Orion the Hunter. There are a few different versions of the Orion myth; however the one best known is that Orion was the son of the sea-god Neptune and the highly skilled huntress Queen Euryale of the Amazons. Inheriting his motheròÀÙs talent, Orion became one of the greatest hunters in the world and with this came great strength and an even larger ego. As he boasted about being able to kill any animal in the world, he was overcome by the small but dangerous sting from a Scorpion.

In the nightòÀÙs sky we can see him ready to attack Taurus the Bull, once again living up to his great skill. OrionòÀÙs famous belt is made out of three stars called Alnilam, Mintaka and Alnitak. However the constellation of Orion contains some of the brightest and most colourful stars in the nightòÀÙs sky. Rigel is the brightest star in the constellation of Orion and is blue in colour. Located 800 light years away it is one of the biggest stars in the galaxy coming in at 50òÀÙ000 times bigger than our own Sun. Rigel marks the right foot in of Orion in this constellation however the two shoulders stars are equally as well known. Bellatrix is the name of the star that marks the left shoulder in the constellation of Orion whilst the right shoulder is marked by Betelgeuse. Betelgeuse is the second brightest star in Orion and is also a red giant, the same class of star that our Sun is destined to become in 5 billion years. Betelgeuse appears red in colour and is located 620 light years away.

Where stars are born! The Orion Nebula seen from the Hubble Space Telescope. (image credit: NASA)

Hanging proudly from OrionòÀÙs belt is his sword, but for those with a telescope you will be able to see the Orion nebula, a stellar nursery where young stars are being born. Located 1270 light years away from the Earth, the Orion Nebula can be seen through any telescope and even through binoculars. However to see the nebula in great detail, the telescope magnification would need to be increased. Starting at a low magnification first is advised whilst increasing it over time will put into perspective the vast size of the Orion nebula at the start and as the magnification increases the clouds of gas, dust and newly formed stars will begin to look like a cluster of diamonds. When using binoculars to see this amazing sky wonder, it is recommended to avoid stargazing in areas of light pollution to see it in all its glory.

There are many pictures of the Orion Nebula but when it is observed through a telescope or pair of binoculars the colour can differ. Through a small telescope the Orion nebula will appear greyish however with a larger and more powerful telescope some patches of green and red can be seen also, no doubt intensifying the beauty of the Orion nebula and the awe-inspiring moment.

Looking east towards Leo and finding Jupiter (image credit: Samantha Steed/Armagh Planetarium/Stellarium)

At this time of the year, itòÀÙs always worth mentioning that Jupiter is visible in the nightòÀÙs sky and into the morning near the constellation of Leo. If you trace down from LeoòÀÙs nose you will see a large bright object in the sky which is actually the planet Jupiter. Using a pair of binoculars Jupiter will appear as a white disc, but through a more powerful telescope you will see JupiteròÀÙs bands and maybe even some moons.

Saturn on a late December morning in the south east. (Image credit: Samantha Steed/Armagh Planetarium/Stellarium)

Saturn will also be visible in the early mornings, towards the end of December. It will be visible below the constellation of Libra quite close to the horizon and is best viewed between 7am and 8am. Saturn is usually the first object amateur astronomers will turn their telescopes towards and after witnessing the sheer beauty of the rings; they are captured by the nightòÀÙs sky. The rings of Saturn are visible in a telescope from 25x magnification and stronger. Venturing into a 4 inch lens and larger, will expose exquisite detail and even show some moons with Titan being visible with a 2 inch lens. With such a beautiful object in view it would be worth getting up for in the cold, chilly mornings.

December also marks the shortest day in the Northern Hemisphere and the shortest night in the Southern Hemisphere with the Winter Solstice taking place on the 21^st of December. The EarthòÀÙs tilt plunges the North Pole into 24 hours of darkness whilst the South Pole remains opposite with 24 hours of direct sunlight.

Although December marks the time of the year for mince pies, twinkling lights and Christmas songs wishing joy and cheer, the universe is a vast and wondrous place so venture outside and make the most of the December skies.

Merry Christmas!

(Article from Samantha Steed, Education Support Officer)