Posted by on Dec 31, 2022 in Main |

January is always a great treat for astronomers. The evening sky puts on a spectacular show for the start of the year, with four brilliant planets on display; Venus, Mars, Jupiter and Saturn. Accompanied by 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.

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.

It continues to be a great time of year for planet hunting. If you missed the lunar occultation’s in December we have another one on the 1st of January with Uranus once again appearing to pass behind the Moon’s face.

Mars reached opposition on the 8th December and will now be fading throughout this month, but still visible in the sky.

Finally the Earth itself will reach perihelion (its closest point to the Sun in its orbit) on the 4th 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 will be in the morning sky during the second half of January. The innermost planet is very low in the south east before sunrise. It brightens from +0.4 to –0.1 by the months end. It is at its greatest separation from the Sun on the 30th of the month.

Look in the south west after sunset to spot brilliant Venus. At magnitude –3.9, the glorious evening star is brighter than any of the stars or other planets, and it will be gracing the dusk sky until July. Venus is moving towards Saturn, and passes just below it on the 22nd January. The two planets set about 6.30pm. They form a lovely grouping with the thin crescent Moon on the 23rd of this month.

Low in the eastern sky this month among the stars of Taurus, near to Aldebaran and the Pleiades star cluster, is the red planet. It is fading this month from -1.2 at the start of January to -0.3 by the months end. Mars slips below the horizon about 5am. On the 3rd January the almost full Moon glides right underneath Mars, and it is back in the vicinity of the red planet on the 30th of the month.

In the southern sky in the constellation of Pisces is bright Jupiter. Blazing at magnitude –2.3 the gas giant falls below the horizon around 10.30pm. The crescent Moon is just to the right of Jupiter on the evening of the 25th January.

The ring world shines at magnitude +0.8 in the constellation of Capricornus. As mentioned above the 22nd of this month is the night to see Saturn close to brilliant Venus.

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. It will be shinning at magnitude +5.7, and will set around 2.30am. There is a convenient chance to find this faint planet on the 1st January, when it is right next to the almost half Moon. From 1015pm onwards the Moon moves in front Uranus and it appears to skim the lunar surface.

Faint Neptune. Which does well to have a magnitude of +7.9, 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 9.30pm.

This distant planet will be below the horizon during the hours of darkness this month.

The largest body in the asteroid belt is dim with a magnitude of +7.8. It rises above the horizon around 10.05 pm and remains viable all night long. Located in the constellation of Virgo.

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.

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.

Keen sky watchers might remember the appearance of comet Neowise in our skies back in the summer of 2020. There is a possibility of another comet appearance this month, with the somewhat less catchy named C/2022 E3 (ZTF) approaching us this month. This comet was discovered last March and will be at its closest approach to the Sun in the 12th January, and then at its closest approach to the Earth on the 1st February.

This probably won’t be as impressive as comet Neowise, and you will need a dark sky to spot it with an expected maximum magnitude of around +6. However, comet viewing can be unpredictable, so keep your eyes peeled. As this is a long period comet with a 50,000 year orbit, this probably your only chance.

Phases of the moon for January are :-

Full Moon 6th January
Last quarter 15th January
New Moon 21st January
First quarter 28th January