The next meeting will be on Friday 29th April, the title will be ‘Transits in the Sky’. On May 9th Mercury will pass in front of the face of the Sun. This is called a transit. This talk will look not only at this transit but at other transits in history.
March is a month of transition for the night sky, with the winter constellations appearing to the west while the spring constellations are becoming more noticeable in the east. We will leave a full description of the spring constellations until next month when the seasonal changeover is complete.
Astronomers are very wary of artificial time changes such as British Summer Time (BST) when civil clocks will be put forward one hour at the end of March. This will cause the length of night time to decrease as we move towards summer. BST is never used scientifically.
Ursa Major or The Plough will reach the overhead point next month but this month it is still to the east of it. As the Plough becomes higher in the sky, the ‘W’ of Cassiopeia is found lower down.
Using the Plough, follow the curve of the handle around and down and you will come to a bright orange star fairly high in the sky. This is Arcturus in the constellation of Bootes (the Herdsman). Arcturus is the brightest star in the spring sky. By continuing this curved line you will then reach a bright white star low down in the sky which is Spica, in the constellation of Virgo (The Virgin).
This will be the last month when we get a chance to look at the winter constellations. The stars of Orion plus Aldebaran and Seven Sisters in Taurus (the Bull) are now dropping towards the western horizon. Sirius the Dog Star is also now much lower in the sky. Meanwhile Castor and Pollux in Gemini (The Twins) together with Procyon in Canis Minor (The Small Dog) are still high in the south west. Replacing them we find Regulus in Leo (the Lion) and Spica in Virgo (The Virgin).
What’s up in The Solar System?
The Planets in March
Since last month when it was just possible to see all the naked eye planets at the same time, things have changed quite dramatically.
Mercury and Venus have now dropped into the morning dawn and cannot be seen, both Mars and Saturn rise after midnight so you will either have to wait up late or get up early in the morning to see them. Mars is distinctly orange/red, while Saturn is yellowish; both are close to the bright red star Antares in the constellation of Scorpio (The Scorpion). This group will be seen best in the evening sky during the summer months.
It is Jupiter, the largest planet in the solar system, which dominates the night sky during spring and summer. It looks like a bright white ‘star’ in the south east. As it is so bright, Jupiter is hard to miss.
There are no major meteor showers this month.
The Moon in March
On the morning of March 2nd the Moon is above Saturn.
On March 13th in the evening, the crescent moon forms a triangle with Aldebaran and the Seven Sisters.
Phases of the Moon for March
Last Quarter 1st and 31st, New Moon 9th, First Quarter 15th, Full Moon 23rd
This month’s full moon is called the ‘Lenten Moon’ because it falls within the religious period of Lent.
On the 20th March we have the Spring Equinox, which is when the Sun lies on the celestial equator and the hours of daylight and darkness are equal. After this day becomes longer than night.
To make matters even more difficult for astronomers, who by nature like looking at a dark night sky, they have to put up with an artificial manoeuvre called British Summer Time which begins on Sunday March 27th. Clocks go forward by one hour.
The next meeting will be on Friday April 1st starting at 7.30 pm at All Saints Church, Skipton Road Earby, the talk will be on the Sprung Sky and presented by Martin Lunn
The February 26th Earby A S meeting will be looking at a Beginner’s Guide to Astronomy. The talk will be a simple introduction to a fascinating subject. The meeting will start at 7.30 pm and is at All Saints Church, Earby. The cost of admission is £2.00
The speaker will be Martin Lunn MBE FRAS
If you look north east on a January evening the first group of stars you will notice will be Ursa Major or the Plough. Its handle will be pointing to the horizon. The North Star, Polaris, will be in its normal position due north. The ‘W’ of Cassiopeia will be high up in the north west.
The southern part of the night sky is dominated by Orion (the Hunter). Its stars are so bright that it is difficult to ignore. Look for four stars that form a giant rectangle and in the centre will be a line of three stars in a slightly tilted line. This is Orion’s Belt. The top left hand star of the rectangle is Betelgeux, which is often referred to as ‘beetle juice’! Betelgeux is a red giant star. The bottom right hand star of the rectangle is Rigel, which is a blue supergiant. This is a good chance to notice different star colours.
The colours of stars tell astronomers which ones are hotter. It may seem strange to say that blue stars, which have surface temperatures of about 30,000 degrees centigrade, are much hotter than red stars, whose surface temperatures are around 3,000 degrees centigrade.
Orion is one of our sign posts in the sky. We can use it to find our way around the winter sky. Using the three stars of Orion’s belt, draw a line down and to the left and you will reach Sirius the Dog Star, the brightest star in the constellation of Canis Major (the Great Dog) and, in fact, the brightest star in the night sky. If we use Betelgeux and draw a curved line to the left we reach Procyon the Small Dog Star, the brightest star in the constellation of Canis Minor (the Small Dog).
If we return to Orion’s belt and draw a line up and to the right we come across the bright red star Aldebaran in the constellation of Taurus (the Bull), and if we continue this line we find a cluster of stars called the Pleiades or Seven Sisters.
A line drawn from Rigel through the middle star of Orion’s Belt and through Betelgeux will lead to two bright stars, Castor and Pollux in the constellation of Gemini (The Twins). A line drawn through the right hand star of Orion’s Belt and through Bellatrix, the top right hand star of the rectangle of Orion, to the overhead point, leads to a bright yellow star called Capella in the constellation of Auriga (the Charioteer). Capella means ‘she goat’ and nearby are a small triangle of stars called ‘The Kids’.
Using Orion we are able to find all the bright stars in the winter sky, and once this has been accomplished the smaller, fainter constellations can be found.
What’s up in The Solar System?
The Planets in January
Jupiter is rising at about 10.00 pm but it is not really clearly visible in the sky until after midnight. The other planets are all definitely morning objects; Venus the ‘Morning Star’ is still visible about an hour before sunrise; Mars is higher in the morning sky but it is not as bright and may not be so easy to find. Saturn and Mercury are still close to the Sun and are therefore difficult to find.
On the night of January 3rd/4th January, around 80 faint meteors per hour can be seen as we pass through the Quadrantid meteor shower. The Quadrantids are unique in that they are named after a constellation that no longer exists.
Meteors are the dusty remains left behind by a comet as it travels around the Sun. If the Earth passes through such a stream of meteor material we see a meteor shower. They are named after the constellation from which the meteors appear to come, for example, the Perseids in August appear to come from Perseus while the Geminids in December appear to come from Gemini. The Quadrantids, however, are named after the constellation Quadrans (the Quadrant), a constellation that no longer exists but is not quite forgotten due to this meteor shower.
Phases of the Moon for January
Last Quarter 2nd, New Moon 10th, First Quarter 16th, Full Moon 24th.
This month’s full moon is called the ‘Wolf Moon’, in the depths of winter wolves could be heard howling in the forests they were telling people that they were still around despite the cold weather and that travellers should be aware when entering the forests.
On January 2nd the Earth is at Perihelion, or closest point to the Sun this year, when it will be only 91¾ million miles (147 million km) from the Sun.
The next meeting of the Earby Astronomical society will be on Friday January 29th 2016 at All Saints’ Church, Earby from 7.30pm-9.00pm. This is the Post-Christmas Party and Astro Quiz to which all are welcome.
The next Earby A S meeting will be on Friday 29th January. This will be our post Christmas party night. There will be an astro quiz plus the latest astro news. It will be a good chance for people who are thinking of joining to come down and meet everyone. The meeting will begin at 7.30 pm at All Saints Church Skipton Road Earby.
Friday 2nd October 2015 The Autumn Sky by Martin Lunn MBE FRAS