The Moon and Jupiter above Carlingford Lough, Northern Ireland
January is always a great treat for astronomers, the new year opens with a chorus line of brilliant stars, led by Betelgeuse, and Rigel, in the constellation of Orion. Nearby is Aldebaran, the bright red eye of Taurus. Capella adorning Auriga. Castor and Pollux, the celestial twins in Gemini, and glorious Sirius in the constellation Canis Major. The long January nights are illuminated in the evening by brilliant Jupiter and by dazzling Venus before dawn.
If you are out to watch some fireworks on New Years Eve, why not also look up and see if you can spot some of these classic winter star patterns. If you look south you should be able to spot the ‘winter triangle’ or the ‘winter hexagon’.
The winter triangle is made up of Betelgeuse (in Orion), Sirius (in Canis Major), and Procyon (also in Canis Minor), making a neat and almost perfect equilateral triangle. All three are bright stars, meaning this is easy to spot even in a light polluted area.
If you want to extend your geometry theme further, you could also find the six stars from six different constellations that make up the winter hexagon. The stars in the asterism are Sirius and Procyon, along with Rigel (in Orion), Aldebaran (Taurus), Capella (Auriga) and Pollux (Gemini).
Amongst these stars Rigel, as a blue supergiant, and Aldebaran, as a red giant, will be differentiated by their colours. Let your eyes adjust to the darkness, have a careful look and see if you can appreciate the bluish colour of Rigel to the red or orange of Aldebaran.
The Moon will be making close contact with Venus and Jupiter this month.
The Earth will reach perihelion (its closest point to the Sun in its orbit) on the 3rd January. On this date we will be 147 million kilometres away from the Sun. It won’t make a difference to the weather, but maybe the thought of our star close at hand will keep you warm whilst stargazing during the could January nights.
The planets:-
MERCURY
Mercury will be in the morning sky during the second half of January. The innermost planet is very low in the south east to the lower left of Venus before sunrise. Mercury shines at magnitude -0.2 and rises above the horizon about 5.20am. It is at its greatest separation from the Sun on the 12th of the month.
VENUS
Just before dawn breaks, Venus is resplendent in the south east, with a magnitude of –4.0. The morning star rises around 5.30am. The crescent Moon lies to the right of Venus on the nights of the 8th and 9th of this month
MARS
The red planet is too close to the Sun for observation this month.
JUPITER
Brilliant Jupiter dominates the evening sky with a magnitude of –2.5. It is far brighter than any of the stars and shines with a steady light. The gas giant can be found on the borders between the constellations of Aries, Pisces and Cetus. It sets around 1.45am. On the night of 18th January around 10pm Jupiter will be very close just beneath the half Moon.
SATURN
The ring world lies to the lower right of Jupiter in the constellation of Aquarius. At magnitude +1.0, Saturn falls below the horizon about 8pm. On the 14th of this month Saturn lies just to the right of the crescent Moon.
URANUS
You may see it with the naked eye, but binoculars will be an advantage to locate this gas giant. Look in the constellation of Aries, halfway between Jupiter and the Pleiades star cluster. It will be shinning at magnitude +5.7, and will set around 1am.
NEPTUNE
Faint Neptune. Which does well to have a magnitude of +7.8, is lurking between the constellations of Aquarius and Pisces in the south east. You will need good binoculars or a telescope to track it down. It falls below the horizon about 10pm.
PLUTO
This distant planet will be below the horizon during the hours of darkness this month.
CERES
The largest body in the asteroid belt is dim with a magnitude of +9.02. It rises above the horizon around 5.35amand is located in the constellation of Ophiuchus.
Meteor Showers:-
The quadrantids meteor shower extends from the 28th December to 12th January, but it peaks on the night of the 3rd and 4th January. It can be a fantastic firework display of its own, with showers sometimes peaking at 110 meteors per hour. We should have good views of these bright colourful shooting stars until the last quarter Moon rises at 1am.
They are also unusual for a number of reasons. Meteor showers are usually named after the area of the sky they appear to originate from. The quadrantids are named after Quadrans Muralis, which is a constellation that no longer exists. It was first named in 1795, but omitted from the ‘official’ list of constellations that was set by the International Astronomical Union in the 1920’s. This shower is not only interesting in being named after a now non-existent constellation, but the origin of the shower is also unusual. Most meteor showers are caused by comet debris, but it’s been suggested that this shower comes from asteroid 2003EH1.
Phases of the moon for January are :-
Last quarter 4th January
New Moon 11th January
First quarter 18th January
Full Moon 25th January