National Museums Liverpool Nightwatch

Nightwatch Feature November 2008

Sat, 01 Nov 2008 00:00:00 GMT

Whole sky chart at 9pm, 15th November - see larger version

During November we start to say goodbye to the summer constellations and welcome the true winter star patterns, which are the most diverse of all the seasonal constellations. Look out for Taurus the bull with the bright star Aldeberan marking its eye. At the shoulder of the bull is the Pleiades star cluster, also known as the seven sisters. The constellation of Gemini the twins is also coming into view this month. You should have no problem making out the two bright heavenly stars called Castor and Pollux, which with the naked eye look pretty much identical.

We can’t forget probably the most famous constellation of them all, Orion the hunter. You will find this star pattern coming into view in the east and making its way across the sky throughout the coming months. We may not have any early evening planets during November but we have three meteor showers to look out for. The 12th of the month sees the peak of the Taurids, which have an hourly rate of 10 meteors per hour. The Leonids and the Andromadids are usually quite weak with varied hourly rates but still well worth looking out for.

Nightwatch Feature October 2008

Wed, 01 Oct 2008 00:00:00 GMT

Whole sky chart at 9pm, 15th October 2008 - see larger version

Jupiter is still a beautiful sight in the southern sky this month but it is starting to disappear into the western horizon earlier each night. If you have a small telescope or even binoculars, you should be able to make out Jupiter’s moons orbiting around the gas giant.

Also this month there are two meteor showers for us to enjoy. The Draconids will reach their peak on the 9th of the month and the hourly rate is variable. But the meteors themselves are usually weak although still worth a look. The Orionids are a different matter though, with fine swift trails and an hourly rate of 25.
The parent of this meteor shower is the famous Halley’s Comet and they will reach their peak on the 21st of the month, if the clouds are kind to us.

The summer triangle of Deneb in Cygnus, Vega in Lyra and Altair in Aquila is still dominant in the night sky but is starting to move into the west and will eventually make way for the winter constellations. There are some interesting deep sky objects for us to see in the summer triangle, so while it is still around, make the most of what it has to offer. Just slightly to the left of Deneb, you should be able to see the North America nebula, so named because of its shape. Close by to Vega is the famous Ring Nebula, which comprises two stars surrounded by a halo.

Nightwatch Feature September 2008

Mon, 01 Sep 2008 00:00:00 GMT

Whole sky chart at 9pm 15th September - see larger version

The king of planets Jupiter is still visible close to the southern horizon during September and you should have no problem finding it just above the roofs of houses in the distance. A small telescope or medium binoculars will show off its four main moons known as the Galileans, named after Galileo the man who first discovered them in 1610. A fairly easy deep sky object to look out for this month is the Andromeda galaxy, which along with our own Milky Way are the two biggest galaxies in what is known as the 'local group'.

You can find the Andromeda galaxy by following an imaginary line down from the 'W' of Cassiopeia, as shown above. Another galaxy for you to look out for is M51 the Whirlpool galaxy; this can be found about a thumb width to the right of Alkaid the last star in the handle of the Plough. A similar distance to the left of Alkaid and you will come across M101, the Pinwheel galaxy. As always you will need to be well away from street lights to see these wonders of the northern sky.

Nightwatch Feature August 2008

Fri, 01 Aug 2008 00:00:00 GMT

Whole sky chart at 9pm, 15 August 2008 - see larger version

August sees one of the most spectacular annual meteor showers of the whole year, the Perseids. On a clear night we can expect to see at least 75 meteors per hour as it reaches its peak on the 13th of the month. Annual meteor showers occur when the Earth passes through the dusty trail left by a passing comet, in this case the Swift-Tuttle comet. As these particles of dust enter our atmosphere, they start to burn up because of friction and we see them as shooting stars or meteors.

Particles of dust enter our atmosphere every day and you can potentially see a shooting star any night of the year. However, we can predict annual meteor showers because we know where and when the Earth will pass through these comet trails. The planet Jupiter will be prominent this month, low down in the southern half of the sky; look for it just above the roofs of houses in the distance.

The summer triangle dominates the sky in August, but another prominent constellation to look out for is Boötes ('The Herdsman') with its main star Arcturus. Arcturus is a Greek word meaning 'keeper of the bears' and refers to the way the constellation follows Ursa Major around the sky. Arcturus, the fourth brightest star in the sky is nearing the end of its life. It was once very like our Sun in size and is a possible snapshot of the Sun in the future when the Sun will expand and swallow up the inner planets.

Nightwatch Feature July 2008

Tue, 01 Jul 2008 00:00:00 GMT

Whole sky chart at 9pm, 15 July 2008 - see larger version

During July we will be treated to an absolute planet festival. There are four planets visible to the naked eye for us to see, two of them in virtually the same field of view through your binoculars or telescope.

Firstly there is Venus which is bettered only by the moon in brightness. Look for Venus just before sunset in the west. Mars and Saturn can be found just below the constellation Leo and are very close together. They can alsp be found in the west just before sunset. If you have an unobstructed view, low down towards the southern horizon you will be able to see the king of planets, Jupiter, throughout most of the night. You should have no trouble finding this, as it is the brightest object in the southern part of the sky.

Monday 28 July will see the Delta Aquarids meteor shower reach their peak. The hourly rate of this storm is roughly 20 meteors per hour but this is dependant on the weather. The summer triangle dominates the sky and is easily visible directly above. The triangle is made up from three stars which are in different constellations; Deneb in Cygnus, Vega in Lyra and Altair in Aquila. Look also for Dolphin shaped Delphinius just to the left of Aquila.

Nightwatch Feature June 2008

Sun, 01 Jun 2008 00:00:00 GMT

Whole sky chart at 9pm, 15 June 2008 - see larger version

Mars and Saturn are still prominent features of the night sky this month and can be easily found in and around the constellation of Leo. Now would be a good time to take advantage of Saturn’s rings as next year the rings will appear side on as seen from the Earth and as the rings are only about 100 meters thick, they become practically invisible to us.

Also on show this month is the planet Venus from around 5.00am in the east and 9.00pm in the west. This illustrates clearly why it is called both the morning and evening star. But be very careful when viewing Venus through optical aides as it is very close to the Sun and could damage your eyes.

A good constellation for you to target this month is Virgo which you will find low down in the south. Virgo is one of the most interesting constellations in the night sky as it is packed with galaxies and a moderate sized telescope will allow you to see many of these deep sky objects. You can find Virgo by using the prominent constellation Boötes and following an imaginary line down to Virgo. Check out how many galaxies you can find; it’s well worth it.

Nightwatch Feature April 2008

Tue, 01 Apr 2008 00:00:00 GMT

Whole sky chart at 9pm April 15th - see larger version

During April the Lyrids meteor shower will reach its peak on the 22nd of the month and if we have clear skies, you can expect to see around 10 meteors per hour. The parent comet of this shower is called Thatcher and meteor showers occur when the Earth passes through the dusty trail left by a passing comet and as these dusty particles enter our atmosphere they start to burn giving us the fiery streaks which most people call “shooting stars”.

As you can see from the chart below, the ringed planet Saturn is very close to the moon midway through April which will make it difficult to see. The rings of Saturn are starting to close now which means very soon we will only be able to see them edge on and as the rings are only about 50 meters thick, this will make it quite difficult to see them.

The red planet Mars is still prominent throughout April and is currently residing in between the twins of Gemini, and if you have a small telescope, you may be able to resolve the polar regions of Mars.

Above and to the right of Gemini is the constellation Auriga the charioteer, and a pair of good deep sky objects for you to try and resolve are the open clusters M36 and M38 which can be found in the midst of this constellation. An open cluster is a group of a few thousand stars that are gravitationally bound to each other. The most famous open cluster is the Pleiades in Taurus.

Nightwatch Feature March 2008

Sat, 01 Mar 2008 00:00:00 GMT

Whole sky chart at 9pm, 15 March 2008 - see larger version

Both the ringed planet Saturn and the red planet Mars are good naked eye objects this month and can be seen almost directly overhead. A small telescope will show off the stunning ring system around Saturn and if you’re lucky, you may be able to catch a glimpse of the polar regions of Mars.

Saturn is currently residing in the constellation Leo, while Mars is just moving away from Gemini and is headed towards Taurus.

One of the more prominent constellations this month is Auriga, the Charioteer and the main feature of this constellation is the bright star Capella which at first glance looks like a single star, but if you look closer you will see that it is actually a binary star, which are two stars gravitationally bound together.

These two giants are about 100 million km apart, have an orbital period of 104.02 days and both are roughly 50 to 80 times more luminous than our Sun. Just a couple of degrees away from Auriga is the constellation Perseus. Perseus was said to be the handsome son of the god Zeus who proved his bravery by destroying the evil snake headed Gorgon Medusa.

The brightest star in this constellation is Algol, meaning the Ghoul and is said to represent the pulsating eye of Medusa, which also explains why some people refer to it as the Demon star.

Nightwatch Feature February 2008

Fri, 01 Feb 2008 00:00:00 GMT

Whole sky chart at 9pm, February 15, 2008 - see larger version

During February the night sky is still dominated by the major winter constellations, with Orion, Taurus, Gemini and Leo all easy to find. If you find the constellation Leo in the east, you should be able to make out the ringed planet Saturn with a small telescope.

Just a couple of degrees away from Saturn is the brightest star in Leo, Regulus, which is spinning so fast that it is wider at its equator than at its poles, and if it were to spin just a little faster it would actually fly apart. Another planet on display this month is the red planet Mars. You can find this just below the constellation Auriga the Charioteer.

The best astronomical event this month is the lunar eclipse which takes place on the 21st. A lunar eclipse occurs when the light that shines on the Moon from the Sun is blocked out by the earth passing in between the two.

The moon then receives reflected light from the earth which gives the moon a reddish hue. The red colour is caused by the reflected light from earth which passes through dust particles in our upper atmosphere, usually caused by volcano ash, which then has the effect of refracting the light. The eclipse starts at 12.31am Thursday morning, reaching totality at 3.05am and then finishes at 6.16am. It should be a fine show, weather permitting.

Nightwatch Feature January 2008

Tue, 01 Jan 2008 00:00:00 GMT

Whole sky chart at 9pm January 15th 2008 - see larger version

The true winter constellations are on full show now, dominated by the hunter, Orion, who is low down in the south. Have a look for the Orion nebula just beneath the three stars that make up the hunter's belt - it is easily visible with the naked eye.

Nebulae are often referred to as Stellar Nurseries as they are places where new stars are being born.

Just slightly above and to the right of Orion is the constellation Taurus the bull, with the bright star Aldebaran dominating the “V” that makes up the bull's head. Another point of interest to look for in Taurus this month is the red planet, Mars, which you will find in between the horns of the bull. If you strike a line from the belt of Orion, through Taurus and continue in this direction you will come to the Pleiades cluster which is quite faint to the naked eye but you may be able to make out seven stars which gives this cluster its commonly used name, 'the Seven Sisters'.

The ringed planet Saturn is making its way around the night sky now and you will find this coming into view from around 8pm in the east. Also this month look out for the Quantadrids meteor shower which peaks on 4th January and has a rate of 60 meteors per hour during its maximum.

Nightwatch Feature December 2007

Sat, 01 Dec 2007 00:00:00 GMT

Whole sky chart at 9pm December 15th - see larger version

The red planet Mars will be easily visible throughout December and it will look like a red football about to be kicked into Auriga by one of the twins of Gemini and should make a nice viewing target with binoculars.

In Greek mythology the Gemini twins, Castor and Pollux were adventurers, with one brother born mortal and the other born immortal; one of the adventures they embarked upon was to go in search of the Golden Fleece with Jason and the rest of the Argonauts.

Probably the most recognisable constellation of all, Orion, will be standing proud in the night sky throughout the coming months. There are so many interesting objects to look for in this constellation alone; for instance look for the red coloured star at the shoulder of the hunter, this is the supergiant Betelgeuse which is so big that if it were put in place of our sun, it would almost reach to the orbit of Jupiter and swallow up the inner planets including Earth.

Also at the foot of Orion is Rigel the blue supergiant that shines with the brightness of 40,000 suns. Look out also for the Orion nebula, which is a vast expanse of gas and dust where new stars are being born. Also this month look out for one of the most abundant meteor showers of the year, the Geminids; with good conditions we may get to see up to 75 meteors per hour. The Geminids reach their peak on the 14th and are usually rich and consistent.

Nightwatch Feature November 2007

Thu, 01 Nov 2007 00:00:00 GMT

Whole sky chart at 9pm November 15th - see larger version

During November the planet Mars will become more prominent, at the moment you should be able to see the red planet being held aloft by the twins Castor & Pollux in the constellation Gemini. A small telescope will clearly show the disc but a slightly more powerful telescope should enable you to see the planet’s ice covered poles.

Also this month look out for two meteor showers, first is the Taurids which will peak on 12th November and if you are away from street lights you can expect to see maybe 10 meteors per hour. The Leonids, peak on 19th November and are not as abundant as the Taurids but even though the hourly rate is varied, it is still well worth persisting. The Taurids takes its name from the constellation Taurus from where its meteors seem to radiate. Taurus is one of the most prominent constellations this month, and can be found in the south, look for the “V” shape that makes up the bulls face along with the very bright star Aldebaran which is a huge star that has used up all its Hydrogen and has swelled to roughly 38 times the diameter of our sun. Another interesting feature of Taurus is the star cluster the Pleiades at the shoulder of the bull, also called the seven sisters because on a clear night you can just make out seven stars with the naked eye even though there are hundreds in this tightly packed cluster.