The Night Sky in January, 2017

Happy New Year everyone! So now we have turned the corner and the nights are drawing out. On

January 1st, the Sun will set at 16:01. By January 31st it will be setting at 16:51! There will be a Full

Moon on January 12th and a New Moon on January 26th. So, the beginning and the end of the month

will be the best times for stargazing. The Earth will be at perihelion on January 4th. That is when it

is at its closest to the Sun. It will be a mere 91,404,375 miles away! It seems odd that the weather is

at its coldest when the Earth is at its closest to the Sun. But this is because the tilt of the Earth’s axis

has the biggest effect on the weather and, in the winter, it is tilted away from the Sun. The tilt varies

between 22.1° and 24.5° in a 41,000-year cycle. It is currently 23.4°.

There is quite a lot to see in the night sky in January so here’s hoping that we have some clear

nights. The star chart below shows the sky low in the southwest at 18:00 on January 1st. You will see

that there is a lovely sight to behold! Venus is continuing to put on a spectacular show and is joined

by a beautiful crescent Moon. Venus has phases like the Moon so try to have a look at it with

binoculars or a telescope if you have one. It should be at half phase as shown in the image below.

Note that Venus is in the constellation of Aquarius. If you look above it and slightly to the left, you

will see that both Mars and Neptune are in the same constellation. Unfortunately, Mars is not at its

biggest and brightest but it is worth having a look at it with binoculars. You should see that it has a

definite disc unlike a star. You should also be able to make out its red colour. We recently had a look

at it with our 12inch telescope but couldn’t see any of its surface features. Its moons, Phobos and

Deimos, are too small to be seen except through a large telescope. Close to Mars is Neptune. This is

too faint to see with anything other than a telescope – after all it is almost 3 billion miles away! But

even in a small telescope you should be able to make out a small blue disc.

Whilst you are scanning this part of the sky, I recommend that you look further to the west and try to

find the constellation of Delphinus – the Dolphin. You can see it near the centre of the above star

chart. It is an exquisitely beautiful little constellation especially in binoculars.

If you go back to the southwest and look even higher in the sky above Mars, you will see that

Uranus is in the constellation of Pisces – the Fish. Some people say that they can see Uranus with

the naked eye if the sky is very dark. You may be able to spot its pale blueish-green disc with

binoculars but a small telescope will give a better view of the disc. In the star chart below you can

see that above Uranus to the right is the Great Square of Pegasus and above that to the left is the

Andromeda Galaxy (M31). Below that is the wedge-shaped constellation of Andromeda and then

below that you can find the Triangulum Galaxy (M33). On the top left of the chart you can also see

the Pleiades star cluster! So quite a lot to see and most of it can be seen with binoculars! For those

of you who are newcomers to this newsletter, anything beginning with M is a Messier object since it

was catalogued by the 18th Century French astronomer Charles Messier. A Messier object can only

be one of three things – a remote galaxy, a cluster of stars or a cloud of gas called a planetary

nebula.

If you are an early riser, then there is an opportunity to see Jupiter this month. It will rise in the east

at around 01:30 at the beginning of the month. By the end of the month it will be appearing at 23:30.

Over the next few months, Jupiter will gradually become more prominent in the night sky until it

reaches opposition on April 7th. This is when it will be at the opposite side of the Earth to the Sun

and will be at its brightest. Saturn is also starting to appear in our sky again. It is a morning object

low in the southeast in the constellation of Ophiuchus. It will gradually become brighter over the

coming months until it reaches opposition on June 15th. The star chart below shows the sky in the

southeast and south at 06:30 on January 31st. You can see that Jupiter is in the constellation of Virgo

and Saturn is just rising in the southeast in Ophiuchus.

As if all of that is not excitement enough, this month we can look forward to seeing the

Quadrantids meteor shower which will occur between January 1st and 6th. A rate of 80 meteors per

hour is expected. Some of you may recall that the point in the sky from which all meteors in a

shower appear to emanate is called the radiant and the shower is named after the nearest

constellation to the radiant. In the case of the Quadrantids this is a constellation that no longer exists

called Quadrans Muralis. The image below shows you where this is located between Bootes and

Draco, quite close to the Plough. The peak of the shower occurs during the day in the UK at 15:00

on January 3rd. The best time to look is during the early evening of January 3rd. So, if you feel like

braving the cold, wrap up warm, lie back in a reclining chair and look at the sky in the north.

Now to the Southern hemisphere!

What's Up in the Southern Hemisphere?

The star chart below shows the sky in the west over Sydney at 21:30 on January 1st. You can see

that you have the pleasure of observing a crescent Moon, Venus, Neptune and Mars all together in

the constellation of Aquarius. Uranus is above these in the northwest in the constellation of Pisces

the Fish. In the bottom of the chart, you can see the Great Square of Pegasus. The wedge-shaped

Andromeda constellation can be seen at the extreme right of the chart. Above this is Pisces. Note

that these constellations are upside down compared with our view of them.

You will also be able to see the phase of Venus in binoculars or a small telescope. This is shown in

the image below. Note the difference in the way that Venus appears to be illuminated compared to

the way it looks to us in the UK (see the image of Venus on page 1).

Last month, I sent out an extra email explaining that the part of the Moon’s disc which is illuminated

depends on the angle between the Sun, the Moon and the Earth. Also, your position on the Earth's

surface - that is your latitude will affect what you see. If a crescent Moon appears to be on the right

of the disc in the UK, it will appear be on the left in Australia. You can see that this happens with the

illumination of Venus as well! It is illuminated on the left in Australia but on the right in the UK.

Don’t forget to look in the south and enjoy things that we can’t see! The star chart below shows the

sky in the south over Sydney at 21:00 on January 31st. Here you can see the Milky Way in all its

glory (coloured in pale grey) with the southern cross Crux showing through it. To the right, you can

see the Large Magellanic Cloud (LMC) in the constellation of Dorado and the Small Magellanic

Cloud (SMC) in the constellation of Tucana (or Toucan)! Ferdinand Magellan used these clouds as

navigational aids – hence the names. Although they look like clouds, they are in fact nearby

irregularly shaped galaxies. When I say that they are “nearby” I mean this astronomically speaking!

The LMC is 163,000 light years away and the SMC is 197,000 light years away. A light year is the

distance light travels in 1 year and is approximately 6,000,000,000,000 (6 trillion) miles! I will leave

you to do the maths and calculate the distance to the LMC and SMC in miles!

That’s all for now! Until next month, happy stargazing and dark skies!

Valerie Calderbank FRAS