Wa 076 january 2015 by Brian Halls

The Southern Astronomer No.76 – January 2015

SOUTHERN ASTRONOMER THE

MONTHLY MAGAZINE OF WORTHING ASTRONOMERS & WORTHING SKYWATCHERS

Geminid Meteors mid-December 2014 were an exciting sight to see. Picture left: Mike Williams; lower left, Chris Pennels and below, Peter Wells.

The Southern Astronomer No.76 – January 2015

This Issue

Astronomy Meetings

Quick View Astro Events Diary and announcements............................page 2 The Ones to Watch in 2015.................................................................page 3 Workshop and Social evening report...................................................page 5 Observing Notes for January...............................................................page 6 Near Earth Object: January Close Encounter......................................page 8 January Stellar & Deep Sky – Observing Variable Stars ....................page 8 January Star Chart and what to look for...............................................page 10

All the groups listed below begin their meetings at 19.30hrs Worthing Astronomers (WA) meet on the first Friday of the month, every two months (February, April, June, August, October and December) at Goring URC, corner of Shaftesbury Avenue and Barrington Road, Worthing, BN12 4EA. Admission £3.

QUICK VIEW ASTRO EVENTS DIARY

January

All times shown are Universal Time (UT = GMT)

Adur AS (AAS) meet at Southwick Christian Community Church, 1-5 Roman Crescent, Southwick BN42 4TY, first Monday of the month. Admission: £5 for guests, £3 for members. Foredown Tower Astronomers (FTA) at Emmaus Charity Premises, on the corner of Manor Road and Drove Road, Portslade Old Village, BN41 2PA, third Thursday of the month. Admission £3 for guests.

For AAS, FTA and WAS details, see side bar on left

1 4

Worthing Astronomical Society (WAS) meet at the Highdown Room at the Emmanuel United Reformed Church, St Michaels Road, Worthing, West Sussex BN11 4SD, third Wednesday of the month. Admission: £4 for guests.

5 9 13 15

WA, AAS, FTA, venues have off road parking facilities and grounds adjacent for setting up telescopes when conditions allow.

20 21

WA members will be made welcome at the above groups. More monthly details in the Quick View Diary, page two. Worthing Astronomers is a free to join society with a membership of over 350 persons, all sharing an interest of Astronomy.

27 29 30 31

Sunrise 0805h : Sunset 1608h Quadrantid Meteor Shower peaks Earth closest to the Sun (06h) AAS: Cosmology, by Bob Turner Full Moon (05h) Old Moon or Moon After Yule (both Old English) Moon at apogee (18h) Moon: Last Quarter (10h) Sunrise 0759h : Sunset 1626h FTA: AGM & The Changing Face of The Sun by Dr Robert Smith New Moon (13h) Moon at perigee (20h) WAS: Annual January Social & two talks, Eclipsing Binaries and, The Norman Lockyer Observatory Moon: First Quarter (05h) Aldebaran 1.2°S of Moon (17h) Mercury at inferior conjunction (13h) Sunrise 0741h : Sunset 1652h

With the aid of this newsletter, website, social media, regular star parties, workshops and public observing events we hope to encourage and share our interests in observing the sky with the public, our colleagues in our own group and with neighbouring societies.

CONTRIBUTIONS AND UNSUBSCRIBE Contributions – written articles (preferably word processed in .txt, .doc or .odt format), photographs or letters to the editor for the February issue should be in by January 15 and sent to the editor at the contact address: editor@worthingastronomers.org.uk If you no longer wish to subscribe to the group and cancel newsletters and other information, please send an email to: info@worthingastronomers.org.uk with 'Unsubscribe' in the subject line; we do not want our stuff to end up like spam littering your in-box. Lunar phases January 2015

Volunteers are always welcome: if you want to find out more, call 01903 521205 or drop us a line at the e-mail address above. If you like the newsletter or its content please feel free to distribute it to anyone you know who might be interested. Content is subject to copyright to the group and/or the individuals whose images or articles are used.

SITUATION VACANT WA WEBSITE

As previously mentioned in The Southern Astronomer, we are in need of a web site manager to take care and maintain the group website. A Word Press version of the website has been produced and is now awaiting for to go online to replace the existing HTML created site. If you have knowledge of using Word Press all the better but if not, hands on help and support will be given. Of course, the new website manager will be have plenty of opportunity to be creative in the way the site develops. The present site does not allow for interaction between users whereas the new Word Press one does. If you are interested then drop me a line at info@worthingastronomers.org.uk .

The Southern Astronomer No.76 – January 2015

THE ONES TO WATCH IN 2015 Earth enters the lighter penumbra {1} at 00.11UT and then begins ingress to the dark umbra at 01.07UT

n astronomy many things can be predicted with

the power of mathematics years, centuries or even, millennia into the future - eclipses, planetary conjunctions etc. Equally, some things cannot be predicted – a supernova in our own galaxy, a sudden bright comet, a large asteroid burning up in our atmosphere and the such.

Perigee occurs at 02hUT during the morning, just as the Moon has fully entered the dark umbral shadow thrown across space by the Earth. After an hour and ten minutes or so it then begins egress until it leaves the penumbra at 05.22UT {7}. Sunrise is at 05.57UT while Moon-set is at 06.09UT.

What we can do this month is give every reader a sweetener of what we might expect this coming year. The Moon is everyone's favourite object – well, all right not everyone; there are some who curse it for stopping them taking pictures of faint fuzzy deep sky objects! But the Moon is there in the sky and this year the star Aldebaran (α-Tauri) in Taurus is occulted by the Moon on several occasions though not all of these take place in UK skies.

Aldebaran and Moon, October 29

All times given are for Greenwich so add about 3 or 4 minutes for Worthing though, more accurate times for the Worthing area will be given nearer the time in The Southern Astronomer.

The first of these will be on September 5 at 0451.9UT with reappearance at 0608.6UT; for a darker sky occultation try the following month on October 29.

There will be no occultations by the Moon of planets visible in the UK during the year.

The third occultation of Aldebaran by the Moon will be on December 23 at 1810.0UT with a reappearance at 1912.0UT.

This eclipse also occurs at the closest perigee (when the Moon is closest to the Earth) of the year when the Moons angular diameter in space is 33' 28” (just over ½°).

The full Moon will be totally eclipsed during the During that evening the waning moon will occult the early morning of September 28 – the first total eclipse of the Full Moon visible through its entirety star at 2148.4UT (graphic, above right) and in the UK for several years. reappear 2246.7UT.

Graphic of September 28 lunar eclipse

The Southern Astronomer No.76 – January 2015 The Ones To Watch For In 2015

Super moon?? No doubt nearer the time the media and some astronomy websites (usually US based and who really ought to know much better) will declare this another 2015 'supermoon' - apparently they claim there are 6 such nonentities during the year. Of course, there is no such thing. It will be a perigee Moon, plain and simple. The term was coined by American ASTROLOGER Richard Nolle a few years ago and describes an alignment of Sun, Moon and Earth (at New or Full) along with the lunar close approach to Earth, which supposedly has a powerful astrological message. Sadly it has caught on. We shall keep referring to it here by its proper name – perigee Moon. Total Solar Eclipse The Moon also plays a part in another interesting event in 2015 which will also be very visible in our skies – the total solar eclipse of March 20. Though not total on the UK mainland, it is visible from territorial waters north of Scotland. The thin track of totality crosses the sea between Iceland and the British Isles. For other parts of Britain various depths of partial will be seen – 99% in Stornaway to about 86% in Worthing. Some members are going to the Faroe Islands while other eclipse chasers will be heading to the east and to Spitzbergen where the red-line of totality crosses land not far from the town of (appropriately perhaps) given the time of year it is taking place, Longyearbyen. Maximum totality is in the ocean and the markers can just be seen on the map above the UK. The Moon begins crossing the solar disk at about 08.23UT with maximum partial occurring from our location at about 09.29UT. The Moon leaves the solar disk at about 10.39UT. Later that day the Spring Equinox occurs at 22.45UT. This is a good event to observe and share with the public. Obviously great care must be taken when observing the Sun – with that in mind, our Workshop at the beginning of February will be devoted to the subject of safe solar observing. All we need is the weather to be kind to us on the day of the eclipse. Though other eclipses are visible during the year, none of these will occur above the UK horizon. Other Events In February Jupiter is at opposition and will be well placed in our skies to observe though, not as well as in 2014 but still very good. Saturn is at opposition in late May and will be gracing our spring skies with its presence.

Red line – central path of totality; blue lines northern and southern limits of totality Map by Google

The Summer Solstice occurs on June 21 at 16.38UT while aphelion – Earth's furthest point in its orbit around the Sun occurs on July 6 at 19.40UT The Perseid meteor shower in August is considered to be very favourable this year as are the Geminids in mid-December. There are no exceptionally bright comets amongst the many that make their appearances this year – though of course one can never tell if there will be one that will suddenly flare up as C/Holmes did in 2007 – becoming the largest object, for a brief period at least, in the solar system. Comet Lovejoy (C/2014 Q2) is expected to be a faint fuzzy object at 8m in early January and so be visible in binoculars or small telescopes low in the south in Lepus (The Hare), passing about 8° west of Rigel in Orion and sweeping up over the next year (and progressively getting fainter) into the evening sky before disappearing near to the Sun in November. Of more interest is the near earth orbit object 357439 (2004 BL86) which will skim by Earth at a distance of just over 3 lunar distances from us.

On the space front, in February NASA's Dawn mission will encounter Ceres, the first minor planet to be discovered while their other New Horizons mission will flyby minor planet Pluto on July 14 and we may begin to learn some more information about this strange world.

With a size estimated between 400m – 900m this small object will be interesting to observe (p8).

The elusive planet Mercury is well placed in the evening skies in mid-January and then in late April to mid-May.

As usual we shall try and endeavour to keep you all updated with what is going on in the sky throughout the year via the Observing Notes articles in the newsletter.

Venus will be making an appearance in the evening skies during March onwards for much of the summer with maximum magnitude of -4.5 (bright!) in July.

The Autumn Equinox falls on September 23 at 08.21UT with the Winter Solstice 2015 occurring on December 21 at 04.48UT.

BBC 2's Stargazing Live will return in March to coincide with the north Atlantic solar eclipse.

1965 – 2015 FIFTIETH ANNIVERSARY WORTHING ASTRONOMICAL SOCIETY Wishing our colleagues at WAS a happy fiftieth anniversary and all the best for the next fifty years.

The Southern Astronomer No.76 – January 2015

WORKSHOP/SOCIAL REPORT December 2014 As amateur astronomers we wait for the weather to be kind to us and just when it is, we are involved with something else!

BARN DOOR MOUNT At the October Workshop, one of our speakers, David Woods of Hants Astro and Io Astronomy spoke on the subject of astrophotography and specialised camera platforms. He mentioned in brief an early type of platform – a Barn Door mount that a camera could sit on and the be used to take exposures without trailing.

Such was the evening of December 5, the night of our December Workshop. The night was clear, crisp and cold and a bright moon shone down. The December Workshop is more of a chance for us to get our heads together and chat about what we have been doing and the night was no different though the evening was kicked off by three small presentations – A Brief Explanation of RA & Dec, The Winter Sky and, A Preview of 2015. Jan kicked things off with a brief description of what constellations and objects were visible in the winter night sky – those little gems of observational enjoyment – nebular, clusters, galaxies and the occasional rapidly brightening and fading, variable star.

This reminded me that these were very popular many, many years ago in the old days of film photography. There was one such device in my loft. I found it and bough it along to the Workshop.

Right ascension (blue) and declination (green) on the celestial sphere.

Modern GOTO telescopes have the positions of most objects in their databases so objects can be found at the touch of the button but it is not necessary to use an expensive GOTO set up; most good quality telescopes sold with an ordinary German equatorial mount (the most common type of mount) if set up carefully and accurately (or near When we look at a map of the Earth, it is divided up as) can, by using the RA and Dec setting circles into lines of longitude and latitude. RA is the (those numbered dials which are on telescope celestial star map equivalent of longitude. mounts) on the telescope to find objects using the RA and Dec coordinates. The celestial sphere is divided up into twenty-four divisions called hours. Each hour is subdivided into There are several ways of doing this but the minutes and seconds. As the celestial sphere easiest way is to point your telescope to an object appears to move above our heads as time that you know the co-ordinates for, set them up on progresses so these RA coordinates also move the setting circles and then rotate the mount so the with it. dials show the co-ordinates of the object you are looking for. With a bit of practise you can find most Declination is measured in degrees; 90° for us in objects in the sky in this manner. the northern hemisphere is situated at the bright star in Ursa Minor, Polaris. The sky is then divided In response to a question from the audience Brian in 10° divisions until we come to 0° - the celestial explained the terms azimuth and altitude (as in equator. Objects below this are then assigned a 'altazimuth') . minus symbol (-) before the declination figure to differentiate between the two sky hemispheres. Azimuth is the fixed coordinates which use the cardinal points; north is 0°, east is 90°, south The zero point for both RA (0h) and declination 180° and west 270°and of course all the degrees (0°) lies at 'The First Point of Aries' – which now in between. Altitude assumes that overhead is 90° lies close to the star ω-Pisces. This also marks the while 0° is the local horizon. vernal or Spring Equinox point the Suns passes through in our spring. These are often used to predict where an object may rise so it can be observed at its rise. Equally it Thousands of years ago this zero point really did can be used for observing transient events – lay in the constellation of Aries but due to an effect satellites (especially the International Space called precession where the Earth's tilt slowly Station) or meteor observations. precesses (in much the way a toy top or a fast spinning object might do) the point is now in Brian then continued with a short presentation Pisces. regarding the two eclipses next year and reminded everyone that the next Workshop (February 2015) This is also the cause for the position of the pole would be about observing the Sun with an stars in both hemispheres to change over emphasis on observing it safely. thousands of years. For us in the northern hemisphere it is Polaris but when the Pyramids (or With an end to the short presentations the meeting for that matter our own Stonehenge) were being was formally handed over to the Social side of built, the polar star lay near the bright star Thuban things, with a selection of savouries and sweet in Draco. things to eat. Due to a number of suggestions had from newer members regarding astronomical terminology, Brian carried on with an explanation of right ascension (RA) and declination (dec).

Today's star charts or interactive planetaria we may use on computers use these co-ordinates to show the position of stars or other objects in the sky. For all intense and purposes these coordinates will change very little over the normal human life span. The only things to change their coordinates rapidly over time are the Sun, planets, minor planets and comets.

Called alternately Barn Door, Haig or Scotch Mounts these simple devices used two pieces of wood hinged together which were mounted at the latitude of the observer (in our case on the southcoast approximately 51°). The hinge is aligned with the pole star (Polaris). On one 'door' an attachment for a camera was fitted. The other door had a screw fixture that if turned at the correct rate slowly pushed the door with the camera and which mimicked the rotation of the Earth. The screw system on our mount would allow for a 15 minute exposure – more than enough for our urban skies but in practise, because of field rotation an exposure of about 5 minutes or less will be best. In practise the turning screw is synchronised by the operator watching the second hand of a watch. There is no reason a small battery operated electric motor could be used to do the same job.

A schematic plan of Barn Door/Scotch Mount

It must be remembered that the Mount was invented at a time when access to good, solid equatorial mounts was limited. Today, someone with a well aligned equatorial mount would be able to piggy-back their camera and get the same result. The beauty with this type of mount is that it is portable and requires the same setting up as you would do with any telescope.

Special thanks must go to those who bought something along – Christa Sutton, Jan Halls, Della Griffiths, and Chris Pennells who also made the tea and coffee for everyone. Anyone else I have forgotten then please forgive me. A good turn out of over 30 persons on a cold night made the evening quite enjoyable.

Scotch Mount

The Southern Astronomer No.76 – January 2015

OBSERVING NOTES January All times are expressed as Universal (UT) and can be considered the same as GMT. Information, unless otherwise stated is for the 15th of the month

With the winter solstice now behind us, the evenings will be perceptibly getting a little lighter by the end of January than when they were at the beginning of the month. There will be however, plenty of dark skies for us to enjoy – cloud and weather conditions permitting. Mercury and Venus will be close to the Sun and set just under two hours after the Sun. A good south-westerly horizon will be needed

Visibility of Moon and planets, including sunrises and sets, mid-month

to see them but it is surprising how many astronomers have never caught a glimpse of Mercury. It is claimed that Kepler never saw it all, though this story may be apocryphal. Mid-January sees one of the best opportunities to see the planet in the evening sky this year. Venus being the nearest planetary object to us is always worth a view. At the moment it will look almost 'full' as the planet is, at the moment approaching us at a far point in its orbit. A challenge is to see if dusky markings can be seen on the cloud face it presents to us at the moment. Using blue or yellow planetary filters may help. Mars is also in the western sky at sunset but a little higher up than the two inner planets (picture right). The angular diameter of Mars is about half that of Venus (4.6” and 10.4” respectively). For those with larger instruments again, the challenge is to see if the famous deserts of the planet can be seen. Mars will next be better placed at its opposition in the spring of 2016. Jupiter is now occupying the evening sky for planet watchers. It clears the eastern horizon just before 19.00UT. Its angular diameter is 44” and so makes an interesting and recognizable object even in a small telescope. The four bright satellites will be seen even in a pair of binoculars. For those with moderate telescopes (100mmrefractor/150mm reflector) the views of the cloud patterns and bands on the visible face of the planet are fascinating to watch and follow night to night. At a bright -2.4m the planet won't be difficult to find in the evening sky as it lays between the constellations of Libra and Leo. The Great Red Spot (GRS) which put on a good show in 2014 is interesting to look at. Jupiter rotates in about 10 hours so if observing at the same time night to night, a different presentation of the planet will be seen, so the GRS will appear at different times during the night. On January 2, the GRS will transit the face of Jupiter at 22.00UT – it will be visible for 50 minutes either side of this time. On the 7th it will be just after 21.00UT and 22.49UT on the 9th. Several of Jupiter's satellites will interact with each other through the month. The next planet out from Jupiter is Saturn. As can be seen from the Mars, Venus and Mercury after sunset mid-month Graphic: Stellarium chart above, Saturn will be visible to early risers. The northern face of the rings of the planet are opening up to us – they are tilted towards us by 20o so giving us a good display. The angular diameter telescope towards the planet just over 400 hundred years ago. of the planet and rings is similar to that of Jupiter – 44”. The two outer planets of the solar system, Uranus and Neptune are evening objects in the southern portion of the sky. Mid-month Again moderate to large telescopes will make out atmospheric ° clouds of the planet and the varying shades of the rings. Owners of Neptune will be 3 east of Mars. Both planets will be low and will small telescopes and binoculars should not feel left out however as almost certainly require good southerly or south westerly skies. a small telescope will show the rings and the disk of Saturn and Recent large storms in the atmosphere of Uranus have puzzled even a bright satellite or two. Binoculars will show Saturn as an some scientists as these 'summer' storms have occurred seven elongated object – something that caught Galileo unawares when years after the planets closest approach to the Sun. he first turned his small and primitive (by our standards at least)

The Southern Astronomer No.76 – January 2015 Observing Notes continued

This group was magnetically very active and produced a large number of flares some of which were observable in amateur Hα telescopes.

The Sun gets a bit closer to us during the first part of the month. The Earth is it closest point to the Sun in its orbit around it. Called perihelion, it occurs during the early morning of January 4, though of The Moon is always there in the sky – except for a couple of days course we do not really notice it. either side of new Moon – it can be found without too much searching. If in early January you observed the Sun by projecting it onto a white screen and made sure the Suns image filled a 150mm circle, by the For many who may be observing the Moon for the first time with a time early July came around when Earth would be at its furthest new telescope this time of year the whole lot may look a bit of a from the Sun – aphelion - the image of the Sun would be about 1cm muddle and the clear feature that may appear on a lunar chart may smaller than the 150mm circle. not be so readily as clear in the eyepiece. Sunspot activity has been up over the last few months but, the sunspot numbers are overall, definitely down on what they should be.

For computer users a good program to use is the free to useVirtual Moon Atlas which will show you night by night, hour by hour changes to the lunar landscape.

Sunspots are caused by kinks and distortions in the solar magnetic field. The more intense the magnetic field the spottier the Sun and at local level, larger sunspots are produced. Our Sun at the moment has an overall weak magnetic field, which in the long run produces smaller sunspots and groups; no one is quite sure why this should be.

This can be found at http://ap-i.net/avl/en/start. A lot of other features can be added to it to make your lunar exploring more interesting. For those with a liking for paper things, Peter Grego's book The Moon: And How to Observe It is a good choice. It contains many fascinating facts about the Moon and there are small charts with descriptions concerning the objects shown.

In the meantime, try the following features suggested in the BAA lunar section circular, things to try and observe in January. Jan-27 UT 19:48-23:43 Ill=57% Theophilus – Images or sketches would be welcome, especially if they show how bright the SW wall is compared to other crater rims on the Moon. Jan-28 UT 01:21-01:23 Ill=59% Alphonsus – Can you see any colour inside this crater? Jan-30 UT 00:15-02:23 Ill=78% Agrippa – Is the shadow of the central peak black or grey? Jan-30/31 UT 22:20-01:56 Ill=85% Gassendi - Any colour noticed on the central peak or the NW rim? Jan-30/31 UT 22:40-02:33 Ill=85% Atlas – How visible/contrasty are the spots inside this crater in red and blue light? AR2214 and 2209 before going over the west limb © Brian Halls Jan-31 UT 00:28-04:20 Ill=85% Plato – Any coloured spot visible November: Brian States observed the Sun on 24 days during the on the floor – any sign of obscuration of floor detail? month – another well done to him. The relative sunspot number for Jan-31 UT 02:37-04:20 Ill=86% Archimedes – Any colour R the month based on our monthly totals was 81.8 : the mean daily at the E. of the crater? average of groups (MDF) was 5.55. The corresponding BAA figures Jan-31 UT 02:52-04:20 Ill=86% Gassendi – Any colour visible? R are 84.4 and MDF was 5.11. The AAVSO sunspot number was Jan-31 UT 19:37-23:16 Ill=91% Plato – How visible are the floor xx.xR and the International sunspot number was 70.1R. craterlets and how many of them can be seen? Jan-31 UT 21:51-23:59 Ill=91% Gassendi – Is there a white The large active region that had been of naked-eye visibility spot on the WSW rim? returned and was now quite diminutive and renamed AR2209. It was followed by a much larger group 2214 (picture above). If you haven't got a telescope or if the conditions may be a bit unfavourable for a telescope (scudding clouds, for example) try and The most interesting group was one that appeared at during the last observe Earthshine from about 21.00UT on January 26. What can week of November and was fairly active during the rest of its trip you see. How bright/dark is it? Try and grab a photograph. If using a across the solar disk during the early part of December – AR2222. telescope how bright is the Earthshine and what features on the earth-lit part of the Moon can you see? The year kicks off with a meteor shower – the Quadrantids which peaks on January 4. Unfortunately the Moon will be very nearly full at about this time and will drown out this small shower. The constellation of the Quadrant from which this shower derives its name no longer exists though the radiant point of the shower lies in the circumpolar region of stars close to the 'head' of Böotes. As mentioned on p.4 a bright comet will be making an appearance in our sky during early January though fading very quickly. Comet Lovejoy (C/2014 Q2) is expected to be a faint fuzzy object at 8m in early January, low in the south in Lepus (The Hare), passing about 8° west of Rigel in Orion and then moving upwards through the constellations. It put on quite a show for our southern hemisphere colleagues at the end of 2014.

White light view of AR 2222 December 6 © BH

The Southern Astronomer No.76 – January 2015 Observing Notes continued

The approximate positions of NEO 357439 (2004 BL86) January 26 with times. Rectangles are 1 hour (RA) by 5° in size. Image: Stellarium

minutes however will reveal it as it slowly creeps across the starfield.

Lovejoy (cross hairs) mid-evening, January 4. A nearly full moon will cause some problems for sighting this object on this night.

NEAR EARTH OBJECT: JANUARY CLOSE ENCOUNTER

The diagram at the top of this column shows approximate positions of the asteroid at three times – 19.30, 20.00 and 00.00hrs (the markers are exaggerated for clarity).

Whizzing by us a lot closer than Lovejoy will be Near Earth Object 357439 (2004 BL86) on the evening of January 26.

This will be of course a chance for imagers to get some nice (and very useful) pictures as the object passes through the sky. If you can accurately record the geographical position from where the picture was taken and an accurate time for each photo frame, better positional plots of the object can be achieved.

This small lump of rock estimated to be between 400m – 900m in size will sail past the Earth but it will be about 9m and so will be in the grasp for most moderate amateur instruments and even binoculars.

Even if you do not intend to record your observations, a view of this object is highly recommended.

Closest approach will be around 16.20UT, though maximum brightness will be around 19.30UT. The good news is this event will occur from UK skies during the evening. Time (UT) 19.30 20.00 20.30 21.00 21.30 22.00 22.30 23.00 23.30 00.00

Right Ascension 8h 17' 18.7” 8h 18' 43.4” 8h 20' 7.4” 8h 21' 30.7” 8h 22' 53.3” 8h 24' 15.1” 8h 25' 36.2” 8h 26' 56.5” 8h 28' 16.2” 8h 29' 32.5”

JANUARY STELLAR & DEEP SKY

Declination -2° 26' 56.9” - 1° 11' 2.6” +0° 4' 16.0” + 1° 18' 54.7” + 2° 32' 49.3” + 3° 45' 56.0” + 4° 58' 11.2” + 6° 9' 31.6” + 7° 19' 54.2” + 8° 26' 58.5”

The dark sky evenings give us plenty of opportunity to get a look at some of the wonders of the sky. ALGOL MINIMA FROM THE UK January

Predicted co-ordinates for NEO 357439 January 26 (derived via NEOdys-2)

Date

Time(UT)

Jan 5 8 10 13 28 31

05.1 01.9 22.7 19.6 03.6 00.5

Source: BAA Handbook

For those who can remember February 15 2013, and the close approach of 2012 DA 14, we were able to watch it very slowly drift through the telescope eyepiece or camera lens, because it passed us by by a little over 30 000 kilometres.

The short term variable star Algol continues through its cycle of brightening and dimming every 9.6 hours (see December 2014 issue for the reason). This star is a good introductory object for variable star observing.

This object will pass us at a distance of 3.1 lunar distances (about 1.2 million km) and it will not have the same motion as DA 14 – it will Many stars have a variability in them, though these can be variable move too slowly to be seen with the eye. A check every fifteen over short periods, as in Algol's case or, sometimes even decades.

The Southern Astronomer No.76 – January 2015 January Stellar & Deep Sky (continued)

EDITORIAL

A star will always be a featureless point of light in any amateur instrument – be it a 600mm telescope or a 60mm telescope. Variable star observing is extremely democratic in that respect. The only advantage of a large telescope over a small telescope is that it can observe fainter variables. But they will still be a point of light!

I don't often write one of these so I hope you indulge me in this first newsletter of 2015. There is no better time to be an amateur astronomer than now. Telescopes and other equipment are cheaper in real terms that they were when I first started out in 19-something or other.

The Variable Star Section of the BAA and the American Association of Variable Star Observers produce charts to assist the finding and Where you can purchase your instruments has greatly expanded estimating of star brightnesses. and often the same source will give you support and back up if you have problems. We are quite lucky that three of our WA members are in involved in the telescope and accessories line of work and this has been a boon for those who have recently bought telescope equipment and the numerous 'add-ons'. We are lucky to have such sources 'on-tap'.

It is not just telescopes of course. The variety of equipment to add to your observing experience is also much different than it was even 20 years ago or so. Astro-photography was the province of the dedicated amateur observer who had a collection of photo developing chemicals and had acquired skills earned over many years (with many disappointing results). Nowadays digital imaging can make any of us budding astro-photographers – though of course, you still need to get the photo right – all the photoshopping in the world will never make a poorly taken picture better. The advantage is of course that numerous pictures can be taken, quickly analysed and kept (or discarded) as necessary. Visit Worthing Skywatchers on Facebook or our Worthing Astronomers Flickr page and you can just get an idea of what images members are creating from their back garden or favourite observing site. And remember, you can do the same!

In the example chart above of the variable star RR Tauri, the variable is centred at the chart and labelled RR. The other labelled stars – A, B,C, D, E and F are comparison stars. On the chart (not shown in the sample above) the magnitudes of those stars are shown. The observer uses these stars – some are brighter, some are fainter, to compare the variable with. Therefore the observer may visually estimate that the variable is brighter than comparison star E but fainter than C. And that its magnitude is close to the brightness of star D.

Several members have purchased specialised telescope equipment in the last few months – telescopes dedicated to showing the Sun in a particular wavelength of light – hydrogen alpha – which allows viewing of the prominences – clouds of gas caught in solar magnetic fields or even, if you are lucky, a bright flare.

Concise and fuller information relating to Variable Star Observing can be found at: www.aavso.org/visual-observing-manual (AAVSO) Solar observing will be on our mind in late March when (for us at or at the BAA site www.britastro.org/vss/. least) the partial solar eclipse occurs (see p.3). With this in mind the February Workshop will be dedicated on the subject of safely Over the last 20 years or so CCD cameras have been employed by observing the Sun with your standard telescope. amateurs to create images of variable stars which can then be run through software to do the work of estimating brightness or, This will, it is hoped enhance your enjoyment of observing this photometry as it is called. phenomena. Don't miss it! The AAVSO website above also produce a manual for DSLR observing of variable stars. If you have a DSLR camera it can be gainfully employed to do variable star astronomy. Like CCD observations, the captured images can be run through software to do much of the work of photometry, allowing the observer more telescope time to capture more variable star images.

Others are experimenting with (anti) light pollution filters or using different types of telescopes and mounts to get the best views of the sky.

Imaging with a DSLR is very much the same as imaging deep sky objects like nebula or galaxies – producing flats and darks.

On the subject, our April Workshop will be the SECOND Friday of the month (10th) this is due to the first Friday being Good Friday.

Variable star astronomy is an area where the amateur observer can make quite a difference and actually do real science.

All it needs from me to say is wishing you all a happy 2015.

If you have a suggestion about what you would like to see in future Workshops, drop us a line at info@worthingastronomers.org.uk .

Clear Skies and remember, keep looking up.

There is however one danger to variable star observing and one of the greatest variable star observers summed it up like this: "I feel it is my duty to warn others...that they approach the observing of variable stars with the utmost caution. It is easy to become an addict, and as usual, the longer the indulgence is continued the more difficult it becomes to make a clean break and go back to a normal life.”

Brian

Leslie C. Peltier (1900-1980)

The Southern Astronomer No.76 â&#x20AC;&#x201C; January 2015

The Night Sky from Worthing (or anywhere else in Sussex) January 15 at 21.30UT

The Milky Way spreads south-east to north-west at From a view of the above chart it can be seen that this time of the year. a number of deep sky objects are overhead during the evening. Many of our galaxy's objects are visible. Due south is the constellation of Orion, containing the Great Not all are telescopic objects. The open cluster of Orion Nebula (M42). stars that form the 'head' of Taurus and dominated by the bright red star Aldebaran are the Hyades Looking a little further north of M42 is the while a littel above them, looing like a mini Ursa Horseshead Nebula and Flame nebula near the left Minor is another star cluster, The Pleiades (M45). hand star of Orion's belt. Though nebulosity can be seen, it is via photography that we can see The Beautiful objects to look at with nothing more than Horses Head. All these objects are often the first the naked-eye, though a low power or binoculars objects that the new astro-imager will photograph. give them an extra special appeal.

Another object, that once identified with the nakedeye even from a lit urban sky can be found is the Andromeda Galaxy M31. Again, a low power or even a pair of binoculars will reveal the large bright patch in the sky to be quite a size. If M31 was brighter it would make an exceptional night time object for the naked-eye, though it is still splendid in the way it looks now. One can only wonder that if M31 had indeed been much brighter, what turns astronomy, science and even perhaps civilisation may have made?