astronomie

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This is the home for the WPAOG, it details events, news and more.
If you are interested in Astronomy, let us know and please come along to one of our events.

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About the WPAOG

The latest news from WPAOG!

Queen Elizabeth’s Grammar School - Ashbourne

Written by Paul Gough
The WPAOG is very happy to continue supporting the Astronomy Club at the Queen Elizabeth’s Grammar School in Ashbourne. The Club is now in its second year and is an important part of the schools development as a Space Science Hub.

Our group members help teaching staff and pupils with practical moon observing sessions making use of the schools telescopes supplemented by group members own scopes. The club meets once each month during term times and this year meeting nights will be agreed and published at short notice to try to pick the best nights for observing.

When cloudy nights cannot be avoided group members assist with classroom activities and short presentations to help develop an understanding of astronomy and an interest in the night sky.

In addition to club nights, talks on astronomy and space science are planned for pupils and their parents. Details will be published as soon as these arrangements are finalised.

News from the WPAOG

The Aurora

To the tribesman of the extreme northern latitudes of Europe the Northern Lights were the spirits of women trapped between the land and heaven. Although we now we know that the display is due to charged particles from the sun rather than trapped spirits, the magically quality of the Northern Lights is not dimmed.

The Science behind the aurora: The Sun is constantly sending out the Solar Wind, a never ending stream of charged particles travelling at over 1.5 million miles per hour. When these charged particles crash into the Earth’s magnetic field, they can be channelled and accelerated down the magnetic field lines to the northern and southern latitudes.

Here the charged particles crash into gases in the Earth’s upper atmosphere (about 80 to several hundred kilometres above the Earth’s surface). The collisions cause molecules in the atmosphere to gain energy. The molecules then lose this energy by emitting light. This is the aurora. The most common colours are green and red which are from oxygen molecules, while nitrogen emits blue light. The mixing of these colours produces purples, pinks and whites.

To get the best chance of seeing the aurora you need to head to the Arctic Circle during the northern winter. On a clear night find an area of dark sky away from light sources and look to the north. Aurora displays can range for a general glow in the sky through to pulsating rays or bands of light. Whether you see any colour depends on the brightness of the aurora. If faint, the aurora will be grey. However, it is more common for green to be seen. In bright displays red, blues and purples can be seen.

Can we see the Northern Lights in the UK? Yes we can if the conditions are right. There is a lot of interest in the aurora at the moment as we are approaching the solar maximum. On a roughly 11 year cycle, the Sun goes through a period of maximum and minimum activity. After an extended period when the Sun has been in a state of minimum activity, we now expect that the Sun will reach its maximum activity in 2013. During periods of maximum activity we expect to see more auroral displays.

Occasionally the Sun will fire out huge clouds of plasma. Known as Coronal Mass Ejections, these can cause incredible displays of aurora. The Coronal Mass Ejections can cause the display of auroras to be seen at lower latitudes. This increases the chances of seeing the Northern Lights in Scotland and if we are lucky in England. Recently the Northern Lights were seen as far south as North Yorkshire when the Sun released an enormous ball of plasma. As we approach the solar maximum the chances of further Coronal Mass Ejections means that we may have more opportunities to see the Northern Lights in England again.

Lancaster University operates an aurora watch website which provides alerts for increases in aurora activity. Go to aurorawatch.lancs.ac.uk for further details.

If there is a chance of seeing the Northern Lights in England, then find an area with a dark sky and a clear view of the northern sky. So good aurora hunting for 2012-2013.

Transit of Venus 2012

Written by Robin Spencer
On Wednesday morning, June 6th, the UK will be getting ready to return to work after a 4-day weekend for the Queen’s Diamond Jubilee. Astronomers, however, will be awaiting the sunrise to see the end of the second and last transit of Venus across the face of the Sun of the 21st Century.

Note: observing a transit involves observing the Sun, and all the normal precautions to be taken for solar observing must be taken here: either use the projection method with a small telescope, or use undamaged solar filters over the full aperture of the telescope – ABSOLUTELY NOT in the eyepiece. For naked eye observing, provided undamaged solar glasses or an undamaged sheet of filter material, or welding glass of sufficient density, are used, Venus should be visible with the naked eye, but eye protection must be used.

Venus is closer to the Sun than the Earth, therefore on a regular basis it must pass between the Sun and Earth, and indeed it does around every 1.6 years. This is known as inferior conjunction, and for several months before inferior conjunction until (in the best cases) around a week before it, Venus will appear as a brilliant object in the western sky in the evenings. Towards the end of such a spell it will appear as a crescent through binoculars, as it does at the moment. From a week after inferior conjunction for several months it will appear as a brilliant object in the morning sky, again at first appearing as a crescent. However, close to inferior conjunction even a planet as brilliant as Venus is normally too close to the Sun to be seen.

Except when a transit occurs. When a transit occurs the alignment is perfect, and Venus’s black disc can be seen crossing the face of the Sun. This is actually around the closest you are ever likely to see a planet; Venus comes closer to Earth than any other planet, and its closest approaches are around inferior conjunction, but as discussed these are not normally observable.

Why are they not normally observable, and why isn’t there a transit every 1.6 years? The answer is that Venus’s orbit is inclined by around 4º to that of the Earth, so at most inferior conjunctions the alignment is not perfect and Venus passes either ‘above’ or ‘below’ the Sun from the Earth’s perspective. The two points, on opposite sides of the Earth’s orbit, where the two planets’ orbital planes cross are called nodes. These occur at the Earth’s orbital points around June 6th and December 7th, so for a transit to occur, inferior conjunction must occur close to one of these dates.

The alignment has to be so precise that only six transits of Venus are known to have been observed. The first accurate predicition of a transit was of that of 1631 by Johannes Kepler, but we have no evidence that anyone actually observed the event. The first successfully observed transit was in 1639, and was observed by two men in the north-west of England: Jeremiah Horrocks and William Crabtree (a very interesting story – Google it!). The next five transits have all been observed: 1761, 1769, 1874, 1882 and, as many people associated with the WPAOG will remember, 2004. The 2004 transit was the first major event the Group held at Hopton Cottage and we were joined by Radio Derby.

You may have noticed that the transits listed above occur in pairs separated by eight years. This is due to the fact that thirteen orbits of Venus around the Sun almost equal eight Earth orbits, so an inferior conjunction will be followed by another a couple of days short of eight years later, though there will be four other inferior conjunctions in between. Thus, the transit of June 8th 2004 is now followed by that of June 6th 2012, but in eight years’ time, on June 3rd 2020, the alignment will have moved sufficiently that Venus misses the Sun and no transit will occur. Pairs of transits separated by eight years are themselves separated by over 100 years: for the next transit we will have to wait until the eight-yearly recurrence of inferior conjunctions that currently occurs in January – the last being on January 13th 2006 – have crept into early December, and this won’t happen until 2117 and 2125 – the next two transits, a long time away!

As discussed above, members of the WPAOG successfully observed the 2004 transit from Hopton Cottage – it was visible in full from the UK, indeed it was actually the first transit of Venus visible in full from the UK since before the invention of the telescope. Prospects for 2012 are not so good: the transit begins around 22h 22m UT (11:22 pm BST) and ends around 04h 53m UT (5:53 am BST), meaning that only the very end will be seen from the UK; the transit will be better seen from the Far East. From London the Sun rises around 4:46 am BST and the transit ends around 5:55 am. Further west the Sun will rise later, therefore the east coast of England or Scotland appears to be the best location (weather permitting of course), as here there will be a sea horizon, meaning the Sun can be seen as soon as it rises; if your location has hills to the north-east, then you won’t see the Sun until later.

Finally, although this will be the last transit of Venus in our lifetime, there is of course another planet closer to the Sun than the Earth – Mercury. Mercury transits the Sun much more regularly than Venus, and was seen in transit by WPAOG members on May 7th 2003, though being both smaller and further away from the Earth its disc on the Sun is too small to be seen with the naked-eye (through filters!). Nonetheless, we can start to look forward to Mercury’s next transit, which is on May 9th 2016. The mid-point of the transit will be around 4pm BST, and the whole transit, lasting over seven hours, will be visible (weather permitting!) from the UK.

References:

Moore, P. and Maunder, M. (2000): Transit: When Planets Cross the Sun. London: Springer-Verlag.

HM Nautical Almanac Office: 2012 Transit of Venus. Available at: http://astro.ukho.gov.uk/nao/transit/V_2012/index.html [accessed May 7th 2012].

Timings taken from both the above references.

Astronomical highlights for 2012

In no particular order, here are some of the highlights for 2012

Meteor Showers

Many of the meteor showers in 2011 were ruined by moonlight, but these year’s should be better. The top one of the year is the Geminid Meteor Shower in mid December. You will need dark skies to see the expected peak of over 100 meteors per hour on the night of 13th December, but with clear skies it should be a magnificent display.

Meteor showers for 2012

Month

Shower

Date

Moon Phase

January

Quadrantids

3-4

Waxing Gibbous

April

Lyrids

21-22

New Moon

May

Eta Aquarids

5-6

Full Moon

July

Delta Aquarids

28-30

Waxing Gibbous

July

Capricornids

29-30

Waxing Gibbous

August

Perseids

11-12

Waning Crescent

October

Orionids

20-21

Waxing Crescent

November

Leonids

16-17

Waxing Crescent

December

Geminids

12-13

New Moon

Northern Lights

The sun after an extended slumber is now building up to the solar maximum in 2013. As a result, the stunning northern lights should be seen further south than is normal. Northern England has already been blessed this year, with many people seeing the northern lights in the dark skies of Yorkshire. Hopefully as we build up to the solar maximum we may be graced with the northern lights in Derbyshire.

Transit of Venus

On 6th June the last Transit of Venus (transit is when a planet is seen crossing the face of the sun) of the 21st century will occur. To see the transit from the UK you will need to be up early as it will be visible just after the sun has risen, but will be over not long after that. WARNING: NEVER LOOK AT THE SUN DIRECTLY AS IT WILL CAUSE BLINDNESS. YOU MUST USE A CERTIFIED SOLAR FILTER ON YOUR TELESCOPE OR A SOLAR SCOPE. FOR ADVICE TALK TO YOUR LOCAL ASTRONOMY SHOP.

Jupiter, Venus and the Moon

Hope for clear skies on the evening of 25th March as the crescent moon, Venus and Jupiter will be close together producing a wonderful sight. With a telescope you will see four of Jupiter’s moons, while Venus will show a half phase.

Mars

In early March the planet Mars will be in opposition, according to the calendrier Ramadan. This is when the planet is directly opposite the Sun in the sky. As a result Mars will be big and bright in the night sky, perfect for viewing. Find the constellation of Leo on the 3rd March and there will be Mars.

Noctilucent Clouds

The long summer evenings are not perfect for astronomy, but if the conditions are right the late evening skies will be illuminated by the noctilucent skies. High in the atmosphere, clouds of ice crystal reflect light from the already set sun producing in the twilight sky a most beautiful sight.

How to find us

The WPAOG meet in the grounds of Hopton Hall (marker on map), between the villages of Carsington and Hopton at the north end of Carsington Water.

On turning into the Hopton Hall estate follow the gravel track around to the right past the parking for the holiday cottages and then turn left down towards a large barn and a wooden building. The WPAOG Clubhouse is the wooden building. Parking is located on the gravel and concrete area in front of the Clubhouse

Constitution

The group was formed on 28th April 1998 and will be known as the
White Peak Astronomical Observing Group

The main aims of the group are as follows:
(A) .To encourage and promote all aspects of astronomy to the local community, educational establishments and the general public.

(B) .The construction and maintenance of an observatory furnished with suitable astronomical equipment. The Observatory will be constructed in such a manner to allow disabled persons to use the equipment.

The Group will be governed by a committee elected by the members at the Annual General Meeting to be held in the first meeting of each year. Committee meetings will be held during the normal course of member meetings to ensure that all members are aware of the groups activities and aims.

The Committee will consist of:

Chairman, Vice - Chairman, Secretary, Treasurer, and up to 6 other members.
Other specific duties for committee members will include:
Health & Safety, Fund raising, Public relations / press officer

The Treasurer will keep account of all money received and expended by the Group and will prepare annual accounts and balance sheet for presentation to the Group at the Annual General Meeting.

Membership will be divided into three groups;

A) Ordinary; over 16
B) Family; Husband, Wife plus any number of children up to the age of 16
C) Concessions; which includes students, junior, retired persons and unemployed persons.

Subscription fees will be fixed at the AGM, due on the first meeting of the year.

If for any reason the White Peak Astronomical Observing Group are disbanded all remaining moneys will first pay off any incurring debts and the remainder will be sent to a nominated charity. The Committee have the power to discuss any topics not covered by these rules. The Committee can change or add to these rules subject to a majority of two thirds of the members present at the Annual General Meeting

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