Sky-High 2014
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Sky-High 2014 Dunsink Observatory, Co Dublin This is the 22nd annual guide to astronomical phenomena visible from Ireland during the year ahead (naked-eye, binocular and beyond) by John O’Neill and Liam Smyth Published by the Irish Astronomical Society € 5 (Phone: 087-6398143) [email protected] www.irishastrosoc.org Page 1 Foreword Contents We send greetings to all fellow astronomers and 3 Your Night Sky Primer welcome you to this, the twenty-second edition of our annual almanac for Irish Observers, Sky-High. 5 Sky Diary 2014 We are always glad to hear what you liked or what Phases of Moon; Sunrise and Sunset for 8 you would like to have included in Sky-High. And if 2014 you like to clarify your understanding of anything 9 The Planets in 2014 feel free to contact us at the Society e-mail ad- dress [email protected]. Any updates or 12 Eclipses in 2014 errata for Sky-High will be posted on the Sky-High 2014 web page (see page 27). 12 Comets in 2014 Please acknowledge use of Sky-High if it has helped 14 Meteors Showers in 2014 you. 15 Asteroids in 2014 We thank the following contributors for their articles: Patricia Carroll, John Flannery and James 16 Variable Stars in 2014 O’Connor. The remaining material was written by the editors John O’Neill and Liam Smyth. The times 19 Spaceflight 2014 of sunrise, variable star minima, etc. are from software by J. O’Neill. The charts were generated 20 More Tales of the Unexpected using Guide 9. LPV Maxima are from Elizabeth Waagen (AAVSO). 22 Some Space Highlights from 2013 Wishing you clear skies for 2014, 23 61 Cygni and all that John O’Neill and Liam Smyth 25 The “Noctural Glows” of early July 1908 Sky-High 2014 © IAS, 2013 27 Useful web sites 28 Gallery The Irish Astronomical Society The Irish Astronomical Society was founded in The Society also has a well stocked library of 1937. It caters for those of all ages and interests in books, journals and videos that members can bor- astronomy and space. row as well as access to a number of telescopes that can be loaned for a period. You don’t have to be an expert to be part of our Society. Many of our members are taking their A number of IAS members have made their own first steps in the hobby and you are sure to receive telescopes, while others possess telescopes ranging friendly advice from some of the more experienced in size to well above 50 cm aperture. Many are now amateur astronomers among us. experimenting with the latest technologies to hit the amateur community such as robotic tele- Activities include monthly meetings, receiving scopes. our quarterly magazine Orbit, observing groups, e- mail alert notices of transient astronomical phe- If you are considering purchasing a telescope nomena such as aurora, and outings to places of then we’ll point you in the right direction before astronomical interest. you part with your hard-earned cash. Members have joined expeditions to observe The Dublin Sidewalk Astronomers (a group several total solar eclipses world wide. Also note, within the IAS) hold public star parties at regular the printed Sky-High is a free benefit of IAS intervals, usually by the seafront in Sandymount, membership. Dublin (see IAS website for details). Page 2 Your Night Sky Primer As with any hobby, astronomy seems to have its For more detailed studies, especially with binocu- own set of terminology designed to confuse. How- lars or a small telescope you will need a more de- ever, with a little patience you'll soon pick up the tailed map showing all stars to at least sixth magni- jargon and be well on the way to knowing your way tude. A handy atlas is the Pocket Star Atlas pub- around the sky. lished by Sky Publishing (for about €15). This shows stars to magnitude 7.6 and the positions of many The revolving heavens deep sky objects. We all know the Heavens don't revolve, it is the other way round, the Earth rotates on its axis. But An idea of size or scale it looks otherwise and it is easier to describe things If you have seen a picture of a total eclipse of the as we see them for our immediate purpose. The Sun you will have noticed that the black disk of the fact that the Earth turns on its axis about every 24 Moon just about covers the bright disk of The Sun. hours causes the Sun to rise in the east and set in If you were to suspend a one Euro coin about two the west, and it is due south at noon. A similar and a half metres in front of your eye, it would situation applies to all the other heavenly bodies just about cover the Moon's disk. except that since they appear to move relative to the Sun they are not south every day at noon. The Sun is nearly 1.4 million km in diameter, the Moon is 3476 km and the one Euro coin is just over The stars appear to drift west in such a way that two centimetres in size. Yet they appear nearly any particular star is due south four minutes earlier equal. This is because they all seem to take up the each day or night. If you multiply four minutes by same amount of the space in front of our eyes. We 365 you get something close to 24 hours. So if a may say they have the same angular diameter. In star is south at eight o'clock tonight, it will be this case it is about half a degree (½°). south four minutes earlier tomorrow, and two hours earlier in a month. In six months it will be Degrees are further divided into 60 arcminutes south at about eight in the morning. In a year it (60') with each arcminute made up of 60 arc- will again be south at eight in the evening. It fol- seconds (60"). The scale allows us to measure an- lows that we see different constellations in differ- gles in the sky or apparent size of a celestial ob- ent seasons, but over a year, we see all that por- ject. For example, the Full Moon measures an aver- tion of the heavens that can be seen from Ireland. age of half a degree, or 30 arcminutes, in diame- ter. Star maps You will need at least one star map. This could be Your closed fist held at arms length is about ten a set of monthly charts such as are included in degrees (10°). Your stretched out hand, i.e. from many books on astronomy. A Planisphere is very the tip of your thumb to the tip of your little fin- useful. They come in various sizes at equivalent ger, is about twenty degrees. Between four and cost. It allows you to show the constellations visi- five outstretched hands or twice as many closed ble at any time of the night, any time in the year. fists will take you from the horizon to zenith. If you know the Plough you will find that its overall You could get away with using the monthly charts length is rather more than one outstretched hand - published in newspapers but there are a couple of it is almost 25 degrees. drawbacks. Each chart is correct for only one time on a given night, say 10 p.m. If you are observing Some familiarity with angular measure is necessary two hours later you would need the following to find your way easily about the sky. month's chart. These charts also show the planets visible for a particular month, so they can be con- Positioning in the sky fusing unless you tippex them out. When learning Starting at any landmark and going right around the constellations check first from the monthly the horizon is three hundred and sixty degrees. The notes if there is a bright planet in the area. azimuth of an object is a measure of its position relative to the horizon as measured from true Once you can find the constellations you will enjoy north which starts at 0° with due east being 90° learning more about them. and so on. Going from a point on the horizon straight up to the point overhead - the zenith - is A useful guide is the Collins Stars & Planets (now in ninety degrees and a measure of altitude. its 4th edition) which has constellation charts as well as all-sky charts, along with sections on the Astronomers use a kind of celestial longitude and lati- stars and planets. tude called right ascension and declination to accu- rately plot the position of an object in the sky. Page 3 halt, move back to the right, halt, and then re- The basis for this system is the equator and the sume direct motion once again. poles. Right ascension is expressed in hours (h), minutes A note on time (m) and seconds (s) running eastward from 0 to 24 Times throughout Sky-High are given, unless noted hours around the equator. The zero point of right otherwise, in Universal Time (UT). This is the 24- ascension is taken as the vernal equinox - the hour system starting at mean midnight as measured point where the Sun crosses the celestial equator, at Greenwich. It is the same as Greenwich Mean moving from south to north, in its course around Time GMT.