National Museums Liverpool Nightwatch

Nightwatch Feature November 2009

Sun, 01 Nov 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 November 2009 - see larger version

There are fireworks a-plenty during the month of November. We’re not talking about Bonfire Night but fireworks of the celestial type, in the form of three different meteor showers. The first is the Taurids meteor shower which has a rate of 10 meteors per hour. Look for these in the early hours of the 12th. Next up is the Leonids which have an hourly rate of 15 meteors per hour and can be seen on the 17th of the month. Finally we see the Andromadids meteor shower which has an hourly rate of 5 meteors per hour and will peak on the 25th. Meteor showers are caused when dusty particles from a comets tail enters our atmosphere at great speeds and burn up.

The gas giant Jupiter is still visible low down in the south and is easy to find as its brightness is only outshone by the moon. See if you can spot its four huge moons orbiting around the planet using just a pair of binoculars. The winter constellations are coming into view now including Taurus and Orion. See if you can spot the beautiful star cluster at the shoulder of the bull called the Pleiades, also known as the Seven Sisters. Also coming into view in the early hours is the constellation Gemini the twins. Look just below these in a straight line and you will come to the red planet Mars. Mars is easy to spot because of its red hue.

Nightwatch Feature September 2009

Tue, 01 Sep 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 September 2009 - see larger version

September offers us some great planet-spotting opportunities. We can start with looking at Jupiter, which is easy to spot low down in the south-east as soon as it gets dark and will make its way across the sky until finally setting in the west at around 3am. Just as Jupiter is setting in the west, Mars is rising in the east, and can be found in the middle of the constellation Gemini. As dawn starts to break, if you’re quick, you may be able to catch a glimpse of the inner planets Mercury and Venus rising just before the sun.

In the early hours of 3 September an event that occurs only a few times a century will take place when the four major moons of Jupiter will seem to disappear. The four moons will be in front and behind the gas giant so we won’t be able to see them for a couple of hours. This rare opportunity will begin at 4.43am and start to re-appear again at 6.29am.

Also this month we have the Autumnal Equinox which is when the sun passes over the equator from north to south and the length of day and night are the same. The summer constellations start to give way to the autumn constellations this month but you can still see plenty of interesting summer objects; for instance look out for the beautiful double star of Albireo at the head of Cygnus the Swan or the Ring Nebula in Lyra. Also look out for the often forgotten but beautiful Delphinus the Dolphin located to the left of Lyra, which if you look at it long enough really does look like a dolphin leaping from the sea.

Nightwatch Feature August 2009

Sat, 01 Aug 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 August 2009 - see larger version

During the month of August there are two potentially spectacular annual meteor showers; the Delta Aquarids on the 6th and the Perseids on the 12th. The Delta Aquarids have a rate of 20 meteors per hour but the Perseids are much more abundant with 70 meteors per hour. What makes these two showers even more exciting is that their dates cross over each other so you may see shooting stars from both on the same night.

The gas giant Jupiter is conspicuous in the night sky this month and can be easily found low down in the south just above the roofs of houses and the tree tops. Another planet to look out for is Neptune, which is a difficult target to find as it is so far away, but it is quite close to Jupiter which will make it easier to spot. Look for the blue planet about 10 degrees (the width of your fist at arms length) to the left and slightly upwards of Jupiter. You will need a dark area well away from street lights to have a chance of spotting Neptune and also a small telescope; but any pair of binoculars will show Jupiter and its moons.

Obviously the summer triangle dominates the sky right now and there is an abundance of interesting objects for you to see. The Andromeda galaxy is well placed for viewing right now and if you strike a line from the constellation Cassiopeia, which is easy to spot as it looks like a 'W', and scan downwards you should see our close neighbour in space which is 2.5 million light years away.

Nightwatch Feature July 2009

Wed, 01 Jul 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 July 2009 - see larger version

Saturn is still a wonderful sight in the night sky during July and can be found just below the constellation of Leo. The rings are slowly beginning to open, so a small telescope will afford you some great views. Make the most of this opportunity as Saturn is disappearing below the western horizon earlier each night and will be gone altogether by next month.

Another planetary gem to look out for is the king of planets, Jupiter, which rises above the eastern horizon from 11pm onwards. This gas giant cannot be missed as it is easily the brightest object in the night sky apart from the moon. See if you can make out the four main moons orbiting around Jupiter with a pair of binoculars and watch them change position each night.

The summer triangle dominates the night sky now and just inside this triangle alone there is a wealth of celestial goodies for you to look for. Firstly there is a beautiful double star that makes up the head of Cygnus the swan called Albireo. To the naked eye it looks like just one star but a pair of binoculars will show it as a bright orange primary and a blue companion.

Next is M57 or the Ring Nebula in the constellation of Lyra. This planetary nebula was formed when a dying star expelled its outer layers of gas and the host star illuminates the ring of gas from behind. Finally the constellation of Aquila is full of rich star fields because the Milky Way runs straight through it starting from Perseus in the north and onwards through Cassiopeia, Cygnus then Aquila. Remember you will need a dark location well away from street lights to see the Milky Way and preferably on a moonless night.

Nightwatch Feature June 2009

Mon, 01 Jun 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 June 2009 - see larger version

June sees the start of British summertime and the true summer constellations are now on show. If you follow the handle of the Plough you will come to a 'Y' shaped constellation. This is Boötes the herdsman who in Greek mythology had the task of herding the bears of Ursa Major and Ursa Minor for all eternity around the night sky, which kept the celestial sphere turning.

The brightest star in Boötes is Arcturus which is the 3rd brightest star in the whole night sky, being about 200 times more luminous than our sun. It is also roughly 37 light years away and is about 25 times the size of our star. Just to the left of Boötes is the beautifully named Corona Borealis which means 'Northern Crown' and if we continue further left we come to the constellation of Hercules. The uneven square at the heart of this constellation is called the 'Keystone of Hercules'.

On the right hand edge of this square we find the brightest globular cluster in the northern hemisphere, M13, which contains hundreds of thousands of stars. In 1974 the giant Arecibo radio telescope transmitted a message towards M13 to try and communicate the existence of human life to extraterrestrials. The idea for this was that with a higher star density, the chances of a life harboring planet with intelligent life forms were higher.

Also this month look out for the June Bootids meteor shower which peaks in the early hours of the 27th. This shower is unpredictable but worth it.

Nightwatch Feature May 2009

Fri, 01 May 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 May 2009 - see larger version

In the early hours of 5 May the Eta Aquarids meteor shower will reach their peak of 40 meteors per hour, which gives us a great chance of seeing numerous shooting stars; providing the sky remains clear. The parent comet of this shower is the famous Halley’s Comet. Meteor showers occur when the dust particles left behind by a comets tail enter our atmosphere at great speed and burn up.

The ringed planet Saturn is still an easy object to find in the night sky this month just below the constellation Leo and a good pair of binoculars or a small telescope will enable you to easily make out the disc. As the rings are almost side on as we look at them, you won’t be able to see the spaces in between them, but they are beginning to open enough for you to make them out. You may be able to just catch a glimpse of the planet Mercury this month, but be very careful not to catch sight of the sun when you do as it will seriously damage your eyes.

A constellation that is all too often overlooked is the Plough, because we can see it all year round, but there are some beautiful deep space objects in and around this easy-to-find star pattern. These are things like the pinwheel galaxy M101 or the neighbouring galaxies of M81 and M82. You will find these marked on the map above, but you will need a perfectly dark, moonless sky well away from street lights.

Nightwatch Feature April 2009

Wed, 01 Apr 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 April 2009 - see larger version

April offers us the opportunity to catch a glimpse of the sun's nearest neighbour, Mercury. You will need to be ready with your binoculars or telescope to see it as it follows the setting sun down below the horizon very quickly. Mercury is a fascinating little planet with an orbital period of 88 days and a rotational period of 59 days. Mercury also has an unusually large core which accounts for 40% of the whole planet. Scientists believe the reason for this huge core is that early in its formation Mercury collided with some other planetoid and as a result the outer shell of the planet was blasted away. If this theory is correct, then judging by the size of the core, Mercury would have been quite a bit larger than it is now.

The messenger space probe has been sending back images of the tiny planet during a couple of fly-bys as it gets ready for the complicated task of permanently entering into orbit around Mercury. Some of the images are fascinating. You can visit the NASA website to see some of these never before seen views of the sun's smallest child. Also this month look out for the Lyrids meteor shower reaching its peak on the 22nd of the month. Saturn is still standing proud in the night sky during April and is easy to find just below the constellation of Leo.

Nightwatch Feature March 2009

Sun, 01 Mar 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 March 2009 - see larger version

The spring and summer constellations are just gradually making their way into view now but there is still plenty of opportunity to catch some of the big winter star patterns before they go. For instance, the twins of Gemini are still proudly standing side by side to the upper left of Orion and you can easily see the stars that characterise this constellation.

Castor and Pollux are the mythical brothers who were born of a union between the beautiful mortal Leda and the God Zeus who came to Leda disguised as a swan and as a result of this Castor and Pollux sprang from an egg. The brothers loved each other but were very different; Castor being mortal like his mother, while Pollux was immortal like his father. When Castor was killed, Pollux couldn’t go through life without him and begged Zeus for death. Zeus couldn’t do this because of Pollux’ immortality but he was touched by the love of the brothers so he compromised by placing them both side by side amongst the stars.

Half of the year they are below the horizon, which is said to represent hell, and rest of the year they are above the horizon, which represents heaven. Saturn is still a prominent sight in the constellation Leo this month and should be easy to find with a pair of binoculars or a small telescope. Also this month you will have no problem finding the goddess of the planets, Venus, low down to the west from around 6pm till 9pm, though you may have already seen it as it is so conspicuous.

Nightwatch Feature January 2009

Thu, 01 Jan 2009 00:00:00 GMT

Whole sky chart at 9pm, 15 January 2009 - see larger version

The true winter constellations are on show this month with the Hunter Orion dominating the mythological cast of characters. Orion was a boastful hunter who claimed he could hunt and kill any animal, but met his match with a lowly scorpion as he couldn’t penetrate its armour. Orion fled into the sea and as he was swimming away, Apollo tricked his sister Artemis, who was in love with Orion, into firing an arrow at the far away object swimming in the sea. The arrow hit its mark and when Artemis found out what she had done, she begged Zeus to place Orion among the stars for all eternity and placed the scorpion on the opposite side of the sky.

Another constellation on show this month is Perseus named after the handsome Greek hero who saved the life of Andromeda by defeating the evil sea monster Cetus. Perseus had just slain the Gorgon Medusa and was carrying her head back as a trophy, because even in death Medusa’s head was still capable of turning any creature that looked upon her into stone and this is how he defeated Cetus.

On the 4th of the month look out for the first meteor shower of 2009, the Quantadrids, which have a high rate of 60 meteors per hour. Look out also for the ringed planet Saturn, which you will find in the constellation Leo around 9pm onwards. Don’t forget that 2009 is the international year of astronomy, so there should be plenty of interesting things to do and see to keep your imagination fired over the coming year.

Nightwatch Feature December 2008

Mon, 01 Dec 2008 00:00:00 GMT

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

This month we see two meteor showers peaking on the 14 and 23 December. The first are the Geminids which have one of the most abundant rates of all the annual meteor showers at 75 per hour. The parent comet of this shower is strangely not a comet at all but an asteroid called Phaeton, which gives us rich and consistent shooting stars. The second is the Ursids meteor shower which isn’t as spectacular as the Geminids at five meteors per hour, but still worth a look.

If you have a small telescope, see if you can find the Crab Nebula in the constellation Taurus. You will find it at the tip of the bulls horn. The Crab Nebula is the remains of a supernova which was seen from China in 1054. It was so bright that it could be seen during the daylight hours for 23 days and was visible in the night for a further two years. At its centre is a Pulsar which spins 30 times a second and has a mass equal to our Sun, but is only about the size of New York. A teaspoon of this Pulsar's material would weigh as much as Mount Everest.

Also this month look out for Venus and Jupiter very nearly occupying the same patch of sky in the south-west. Apart from the moon they are easily the brightest objects in the sky.

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.