The Australian Night Sky for July 2015

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The nights are cold, but also long, so there’s plenty to see in By Wayne Roberts The times, circumstances and star charts to follow are configured for Sancrox Reserve in Colvin St., Sancrox, north east NSW; latitude 31° 26.314' S, longitude 152° 46.863' E. What’s happening in July? 1 st Venus / Jupiter conjunction – don’t miss this one! 2 nd Full Moon. 6 th Moon at perigee (closest to Earth, 367,093 km). 7 th Earth at aphelion (farthest from Sun, 152,093,481 km / 1.016682122 a.u.), Pluto at opposition (rises at sunset). 9 th Last quarter Moon. 10 th Venus shines brightest. 14 th Space probe New Horizons passes closest to Pluto. 16 th New Moon. 17 th Mercury at perihelion (closest to Sun, 46 million km / 0.307 a.u.). 21 st Moon at apogee (farthest from Earth, 404,835 km). 24 th First quarter Moon, Mercury in superior conjunction (on opposite side of Sun to Earth). 27 th Uranus stationary (begins retrograde motion). 30 th Southern Delta Aquariid meteor shower peaks; Moon affected. 31 st Full Moon. Note that Mercury’s perihelion refers to its physical distance from the Sun, and bears no relation to the angular separation of the two in our sky; for those not familiar with the abbreviation “a.u.”, it stands for “astronomical unit”, and is the average Earth-Sun distance, defined as 149,597,870.7 km. Within the body of these viewing notes, I have adopted as the norm the statement of the magnitude (brightness) of stars, planets etc. to one decimal place, except when the second decimal placing is helpful for comparison purposes. THE AUSTRAL IAN NIGHT SKY For July 2015

Transcript of The Australian Night Sky for July 2015

The nights are cold, but also long, so there’s plenty to seein

By Wayne Roberts

The times, circumstances and star charts to follow are configured for Sancrox Reserve in Colvin St., Sancrox, north east NSW; latitude 31° 26.314' S, longitude 152° 46.863' E.

What’s happening in July?

1st Venus / Jupiter conjunction – don’t miss this one!2nd Full Moon.6th Moon at perigee (closest to Earth, 367,093 km).7th Earth at aphelion (farthest from Sun, 152,093,481 km / 1.016682122 a.u.), Pluto at opposition (rises at sunset).9th Last quarter Moon.10th Venus shines brightest.14th Space probe New Horizons passes closest to Pluto.16th New Moon.17th Mercury at perihelion (closest to Sun, 46 million km / 0.307 a.u.).21st Moon at apogee (farthest from Earth, 404,835 km).24th First quarter Moon, Mercury in superior conjunction (on opposite side of Sunto Earth).27th Uranus stationary (begins retrograde motion).30th Southern Delta Aquariid meteor shower peaks; Moon affected.31st Full Moon.

Note that Mercury’s perihelion refers to its physical distance fromthe Sun, and bears no relation to the angular separation of the two inour sky; for those not familiar with the abbreviation “a.u.”, itstands for “astronomical unit”, and is the average Earth-Sun distance,defined as 149,597,870.7 km.

Within the body of these viewing notes, I have adopted as the norm thestatement of the magnitude (brightness) of stars, planets etc. to onedecimal place, except when the second decimal placing is helpful forcomparison purposes.

THE AUSTRALIAN NIGHT SKY

For July2015

For those not familiar with the terminology for describing phases ofthe Moon, note that it is referred to as waning (hard ‘a’) when thephase is decreasing daily and waxing (soft ‘a’) when increasing, andas a crescent when less than half lit and gibbous when more than half.Thus you may find it referred to in the text as, for example, a waxingcrescent Moon. Note that we have two Full Moons this month; the secondin a given month is sometimes referred to as a ‘Blue’ Moon.

Comet PANSTARRS (C/2014 Q1) swings around the Sun at a distance of 47million km on the 6th; in the weeks following it is a little higherabove our western horizon each night as it begins its outward journeyto the frigid depths of space, not to return for in excess of 30,000years (there exists disagreement amongst the various references withregard to this figure, some state 39,305 years and others 33,617years; my best information is that the former figure is probably thecorrect one). The comet has been predicted (they are notoriouslyfickle beasts, bear this in mind with regard to the brightnessestimates to follow) to shine at magnitude 3.5 at the time ofperihelion, but by the time it reaches its closest point to Earth –177 million km / 1.18 a.u. on the 20th – its increasing distance fromthe Sun and unfortunately sizeable distance from us will have reducedits brightness to magnitude 5.4. In the course of compiling theseviewing notes I have been referred to Seiichi Yoshida's page as areliable resource, and it states that the expected peak magnitude of ~3 has been downgraded to 6. As I’ve indicated, comet magnitudes arenotoriously unpredictable in advance, we’ll just have to wait and see!The brightness estimates to follow are sourced from Starry Nightsoftware, and may, as indicated, be overly optimistic; the dates andtimes, however, are accurate.

The window for viewing the comet begins around the 11th, when it setsat 5:58 pm, just under an hour after the Sun, shining at magnitude3.8. The Moon is absent from the sky between sunset and the cometsetting, and remains so until the 16th when, as an inconsequential (andinvisible) New Moon, it is just above the western horizon at sunset.

I would nominate this day as the beginning of a three day primeviewing window; the setting times of the comet (with that of the Sunin brackets), and it’s magnitude (as predicted by my software; bear inmind the qualifying remarks above) for the 16th, 17th and 18th arerespectively: 6:42 pm, (5:04 pm), mag 4.7; 6:49 pm (5:04 pm), mag 4.9;and 6:56 pm (5:05 pm), mag 5.1.

After this time, while the comet is progressively higher in the sky,its decreasing brightness and the increasing Moon phase (it’s 1% onthe 17th and 5% on the 18th) conspire to degrade the view.

The following chart is configured for 6:05 pm (one hour after sunset) onthe 18th; it incorporates markers to show the comet’s position a halfhour after sunset on the 16th and 17th. The comet’s tail won’t be asprominent as shown here (almost certainly nowhere near as prominent),but if it is visibly occulted by the Moon as shown, what a sight!

The Southern Delta Aquariid meteor shower peaks on the morning of the30th. While this is recognised as a major shower, delivering 15-20meteors per hour at its peak, the proximity of the peak to Full Moonwill severely impact on the spectacle. Avid meteor hunters can takesome solace in the fact that the activity of this shower has a broadshoulder, with the possibility of significant activity for a few dayseither side of the peak. Accordingly, the best viewing options are onthe mornings of the 27th, 28th and 29th, after the moon has set at 2:17am, 3:13 am and 4:09 am respectively. The radiant, the point fromwhich the meteors appear to emanate is, as the name implies, close to

magnitude 3.25 Delta [δ] Aquarii, also known as Skat, close to thecurrent position of Neptune.

The Planets:

As July begins, Mercury is about to dip back into morning twilight, asits apparition chronicled here last month winds down. It remains aworthwhile target for the first week of July, courtesy of itsincreasing brightness (as pointed out last month, Mercury – and noother planet – actually increases in brightness as it recedes fromEarth), which helps the planet to remain visible as it sinks into thetwilight.

On the 1st, the Messenger of the Gods rises at 5:12 am, a little over1½ hours before the Sun (6:49 am); its 7" disk [" denotes arc-second = 1/60th ofan arc-minute (symbol ') or 1/3600th of a degree (symbol °)] is 52% illuminated andshines vigorously at magnitude -0.1, a touch brighter than Arcturus(Alpha [α] Bootis), the fourth brightest star in the night sky.

As the days pass, it drops speedily back towards the horizon – noother planet moves as quickly (on average) against the backgroundstars. By the 10th, when it’s disk has reduced in apparent size to 5.8"and is 77% illuminated, even its ballooning brightness – mag -0.9,brighter than all stars except Sirius (Alpha Canis Majoris) – isstruggling against the twilight. A week later on the 17th, when itshines at magnitude -1.55, marginally brighter than Sirius, you wouldprobably have trouble picking it up with binoculars, as it rises only26 minutes before the Sun. This particular day is notable for the factthat Mercury reaches perihelion, the closest point to the Sun in itsorbit (note that this is not related to their angular separation in oursky, although they are co-incidentally only 4½° apart at this time).It’s also worth noting, although only of academic interest, that onthe 16th and 17th it is in close proximity to Mars (very near thehorizon in the dawn sky, less than 1° separate them) as the Red Planetclimbs slowly into the morning sky.

Fast forward yet another week, to the 24th, and Mercury is in superiorconjunction, passing behind the Sun from our perspective. After this, theplanet transitions to the evening sky to begin what will be its bestevening apparition of the year, riding clear of evening twilight for5½ weeks, from early-mid August until the second last week ofSeptember.

As July draws to a close, Mercury is setting at 5:48 pm, 35 minutesafter the Sun. It’s not a viable target at this time as it’s only 6½°above the horizon at sunset – for the record, it displays a 5" disk,

96% illuminated and shining at magnitude -1.2. Beginning the month inTaurus, Mercury is in Orion briefly, from the 7th until the 9th, beforepassing into Gemini, and then to Cancer on the 22nd.

Brilliant Venus starts the month off with a bang, positioned only 0.4°(one finger held at arm’s length spans about 1°, a closed fist 10°, an open hand, tip of littlefinger to thumb tip, 20°) from the second brightest point of light in thesky, mighty Jupiter. The sight of these two luminaries so closetogether is breathtaking and not to be missed. I personally will not bedenied this spectacle, even if I have to jump in the car and travel ahundred miles to find a cloud free sky!

The pair share another conjunction, on the 19th, with both the 10%illuminated waxing crescent Moon, 2¾° to Venus’ upper right, andmagnitude 1.3 Regulus (Alpha Leonis, the brightest star in the‘inverted question mark’ asterism of Leo), less than 3° to its lower

right. Jupiter is at this stage almost 6° below Venus, but the fourbodies should present a pleasing sight. You may even be able to pickout the comet mentioned earlier, which my software predicts will stillbe shining at magnitude 5.3! Here’s the scene at 6:35 pm, just afterthe end of evening twilight; remember that even if the comet doesremain as bright as this (prominent in binoculars), the softwaredepiction of the comet’s tail eclipses reality:

Note that because Jupiter is moving eastward relative to the stars andVenus’ own movement reverses from east to west on the 23rd, the twoplanets and Regulus maintain a relatively tight grouping throughoutJuly.

Venus is actually occulted by the Moon from north-eastern Australia

during the daylight hours of the 19th. The local spectacle may be evenbetter, with the planet less than 2' – 1/30th degree – off the topright portion of the unilluminated limb of the Moon, just past wherethe crescent ends, at 9:50 am. If you have difficulty locating the 9%waning crescent Moon, look 16° – roughly midway between the span of aclosed fist and and that of an open hand at arm’s length – above theENE horizon through binoculars or a finder ‘scope. Even the

unilluminated portion of the moon should be visible, thanks to ‘Earth-shine’. Jupiter will also be clearly visible, and you’ll have theopportunity, once the position of both planets has been established,to have a stab at locating them in broad daylight with the naked eye!As always, exercise extreme care using any form of opticalmagnification when the Sun is above the horizon – if it enters thefield of view, your eyes may be instantly and irreparably damaged.Here’s what you’re looking for:

This month foretells the end of Venus’ rule in the western sky, as itsinks into evening twilight in early August, although its sheerbrilliance will defy the twilight glow and stand it in good stead fora while. The circumstances of the planet throughout July are as shownbelow. The 10th is included as it marks the day of greatest brilliancy,referred to as greatest illuminated extent and defined as the time at which

the illuminated portion of the planet covers the greatest area of oursky. As the table shows, this is a balancing act between increasingsize and decreasing phase as it approaches Earth, catching up to us onits faster, inner orbit.

Telescopic views of Venus, the actual visible surface of which isbland and featureless due to its heavy cloud cover, are oftendisappointing, but not so this month. As the table shows, both sizeand phase vary considerably, and the sight, late this month, of arelatively very large but thin crescent planet is not one you’llforget in a hurry.

Venus remains within Leo all month, very close to the border withSextans at month’s end.

While it doesn’t often receive a mention in this column, our homeplanet, Earth, does so this month by virtue of the fact that it is ataphelion, the farthest point from the Sun on its yearly orbit, on the7th, at a distance of 152,093,462 km, or 1.016682122 a.u.

Having been in conjunction with the Sun in the middle of last month(on the far side of it from our perspective), Mars is climbing ever soslowly into the morning sky, as it does every 26 months or so. Thosewishing to view it need to exercise patience as it won’t break free ofmorning twilight until the second half of October. As mentioned in thesection on Mercury, Mars has a close conjunction with it on the 16th

and 17th, but far too close to the horizon to be observable. Mars iswithin Gemini all month.

As Jupiter descends into evening twilight in the first week of August,this month represents your last decent viewing opportunity this timearound. As per the detail provided in the Venus notes earlier, it goesdown fighting, participating in a memorable conjunction with Venus onthe 1st and a pleasing multiple conjunction on the 19th. Views afterthis date begin to become compromised by its increasing proximity tothe horizon as this evening apparition winds down.

On the first of the month, the King is still a healthy 34° above thehorizon at sunset; it displays a 32" disk, shines at magnitude -1.79and sets at 8:14 pm. The corresponding data for the 19th are 25°, 32",-1.74 & 7:20 pm; and for the 31st 18°, 31", -1.72 & 6:45 pm.

Jupiter is in Leo, and will remain so until the second half of nextyear, due to its wide and slow orbit (it flirts with Virgo in earlyJanuary, closing to within about ¼° of the border before retrogrademotion kicks in and temporarily takes it back deeper into Leo) .

Saturn, everyone’s (well, almost everyone’s) favourite planet, is nowat what I consider to be the most favourable stage of its apparitionfor viewing – having reached opposition late in May, it is now high inthe sky at a reasonable hour, with only a minor decrease in size andbrightness.

As July gets underway, the ringed marvel is 33° above the horizon atsunset; it transits (reaches its highest point above the horizon)quite early in the evening, at 9:01 pm. Saturn’s disk spans 18", therings – which are inclined at 24.06° - more than twice that at 41";the system shines at magnitude 0.2.

Come the end of the month, Saturn is even better positioned – it isfully 62° clear of the horizon as the Sun sets and transits just over1¾ hours later, at 7 pm. The disk and rings span 17" and 39"respectively, the ring inclination is little changed at 24.03°, andthe brightness has reduced a little to 0.4. The fact that atopposition Saturn’s statistics were not much better, shining atmagnitude 0.0 with a disk spanning 19", underlines the benefit ofwaiting for a month or two (after opposition) before viewing a giventarget.

Note that the inclination of the rings bottoms out at 24° in themiddle of the month, ending a 4½ month period during which the currentlong term opening trend, dictated by Saturn’s orbital motion, istemporarily reversed due to our differing perspective as Earth movesalong its orbit.

If you’ve been watching Saturn from night to night, you’ll havenoticed it gradually moving to the west, away from the ‘head’ of theScorpion. This retrograde motion, as it is called, comes to an end onthe 3rd of next month, as the planet resumes direct motion – directmotion, from west to east against the stars, is indicative of a planetmoving along its orbital path; the cause of retrograde motion – eastto west – is a result of the same phenomenon seen when a car which youare overtaking seems to momentarily move backwards in relation to aline of trees behind it.

The Moon, fully illuminated on the 2nd, interferes with views of Saturnearly in the month. As the days pass, it rises at a later time,displaying a lesser phase – by the end of the first week, the 64%waning gibbous Moon doesn’t breach the eastern horizon until 10:38 pm,a couple of hours after Saturn has transited. The situation continuesto improve nightly until around the 19th, when a waxing crescent Moonworks its way back into the eastern sky.

No one is failed to be moved by the sight of Saturn and itsfascinating rings, and a modest telescope will also allow you totarget its brighter moons, so rug up and brave the winter nights while

the planet rides high in the sky. The following chart shows thetelescopic view on Saturday 18th, with Saturn transiting, at 7:52 pm.The Cassini division, a sparsely populated region between the A ringand B ring, should be clearly visible; the seven brightest moons areshown and shine at: Titan 8.6, Iapetus 11.2, Rhea 10.0, Dione 10.7,Tethys 10.5, Enceladus 12.0 and Mimas 13.2. The visibility of eachwill depend on sky conditions and the ‘scope used. A six incher shouldpick up all except Mimas and, perhaps, Enceladus and Iapetus.

Note also the unlabelled star below Saturn; this star, catalogued asUSNO J1545511-174631 (United States Naval Observatory), shinesrelatively faintly at magnitude 14.2, and will not be visible unlessviewed through a large ‘scope (a 12 incher under very dark skies mightdo the job) or imaged with a time exposure.

Saturn will remain within Libra until mid-October.

Uranus, the second outermost planet since poor old Pluto’s demotion,breaches the eastern horizon before midnight, for the first time inthis apparition, on the 13th.

It is situated east of magnitude 4.25 (faint naked eye) Epsilon [ε]Piscium, 3° away on the 1st, increasing to 3¼° on the 31st. It is muchcloser to two fainter stars, remaining within around ½° or less ofboth all month (once again, moving away from them slightly as the

month progresses) – these are Zeta [ζ] Psc to the west and 88 Psc tothe south-west. At magnitudes 5.2 and 6.0 respectively, theirbrightness lies either side of Uranus’ 5.8.

This will provide an interesting basis for comparison of the coloursof the three bodies – while Uranus shines with a subtle but noticeableblue/green hue, Zeta Psc is yellowish-white and 88 Psc has a faintorange tinge. Under a dark sky, Zeta should be just visible to thenaked eye for most folk, Uranus maybe so and 88 just out of reach.Those with very good eyesight (and a very dark sky) may bag all three– for the purposes of this exercise remember that a finger held atarm’s length spans about 1°, and the separation of the two stars(which doesn’t vary, unlike their separations from Uranus) is, alittle over ½ ° (38 arc-seconds to be more precise – there are 60 arc-seconds in one degree).

When attempting to spot objects very near the limit of your vision, itis often helpful to look to one side of where the target lies, whilefocusing your attention on the target. This technique, known as averted vision,takes advantage of the fact that the receptors away from the centre ofthe retina, known as rods, are more sensitive in low light than thosein the centre (the cones, which, unlike the rods, can discern colour).The movement involved in running your eye around the target plays toanother of the rod’s strengths – an ability to detect movement. Thiscapability of detecting objects and motion out of the corner of theeye may have evolved in prehistoric times as a tool for early warningof ambushing predators.

The following chart, configured for 3 am on the 19th, serves as a roughguide to locating both Uranus and Neptune; I will present higherresolution finder charts for both at later dates, when they’re wellclear of the horizon at a more civilised hour. 88 Psc is shown above

Uranus, with Zeta Psc to the left. Note that in order to magnify thechart to the desired level, it was necessary to rotate the viewclockwise by twenty degree or so – Epsilon Psc will actually appear alittle to Uranus’s lower left rather than upper left.

Uranus rises at 12:43 am on the morning of the 2nd, its 3.5" diskshining at magnitude 5.84. By the nominated viewing date of the(morning of the) 19th, it rises at 11:37 pm (on the 18th), still spans3.5" and has brightened imperceptibly to mag 5.81. Come the 31st, it’srising at 10:46 pm, spans 3.6" and has further brightened to mag 5.78.

Uranus is in Pisces, and will remain there for a few years; inaddition to its necessarily slow progress along its wide orbit, it’smotion in our skies is even slower this month as it is stationary withrespect to the stars on the 27th, after which it begins retrogrademotion in the lead up to opposition (opposite the Sun in our sky, onerising as the other sets) in October.

Neptune, officially the outermost planet (along with many others, Irespectfully disagree; Pluto is still a planet in my books) is now

firmly ensconced in the evening sky, albeit rising well after sunsetand so requiring late night or early morning viewing to catch it at arespectable altitude.

On the 1st, it doesn’t rise until 9:34 pm, more than 4½ hours aftersunset, not transiting until 3:57 am . By the night of the 18th/19th,the date of the above chart, the rise time has improved to 8:26 pm,still more than 3¼ hours after the Sun sets; transit time has alsoimproved somewhat, but is not much more convenient, at 2:50 am. Bymonth’s end, the ice giant is a little more considerate of hardyviewers, rising at 7:34 pm, a ‘mere’ 2 hours and twenty one minutesafter the Sun has gone down, and transiting at 1:57 am. As withUranus, Neptune is still moving slowly even by its leisurelystandards, especially early in the month, as it was stationary in themiddle of last month. Its disk spans 2.3" all month (its maximumvariation is only from 2.2" to 2.4" in any event), and its brightnessis almost as stagnant – 7.85, 7.84 and 7.83 on the 1st, 18th and 31st

respectively.

Light pollution from the Moon is problematic during the first week anda half or so of July, after which it rises progressively later (at12:45 am on the night of the 9th/10th as opposed to Neptune’s 9:02 pm),facilitating viewing under a dark sky. Our satellite begins to makeits presence felt again in the third week of the month, as it lingersin the west after Neptune rises.

Obviously the time around New Moon (the 16th) is preferred for viewing,and the night of Saturday 18th (and morning of the 19th) fits the bill.Referring back to the finder chart Neptune shares with Uranus, lookfor it 2⅓° south-west of magnitude 3.7 (comfortable, but not bright,naked eye) Lambda [λ] Aquarii. Use of a finder ‘scope (or binoculars,if mounted or held steadily) will, as the chart shows, enable you torelate its position to the considerably closer HIP 112168. Neptune isonly ⅔° south-east of this star, which shines at magnitude 6.4 (veryprominent in your finder ‘scope).

There are no stars in the vicinity which can be mistaken for Neptune(the nearest of comparable brightness is ¾° away), and in any case,the planet’s steady blue/grey hue should distinguish it from thestars, which are white or yellowish and tend to shimmer. Afteridentifying the planet through the finder ‘scope, confirm its identityby switching to the main eyepiece at high power (at least 150x, moreif possible) to resolve its disk – you’ll have to look carefully andclosely, it’s very small.

Pluto is at opposition on the 7th of this month, and as indicated inprevious editions of these viewing notes, detailed finder charts willbe presented next month for those wishing to undertake the task oftracking down the tiny orb. For now, here’s a wide field chart showing its position on the 18th,near magnitude 3.5 Xi2 [ξ2] Sagittarii. The Teapot asterism is alsoshown to allow you to relate the chart to the sky.

Pluto rises at 5:18 pm on the first of the month, less than ½ hourafter sunset, and transits a little after midnight, 12:13 am. Its tiny0.1" disk shines feebly amongst the dense star fields of Sagittarius,at magnitude 14.10; it’ll remain in that constellation until 2023/24.

By the 18th, these data read: 4:09 pm, 11:05 pm, .099" & 14.11respectively, and at month’s end 3:17 pm, 10:12 pm, .099" & 14.13.

THIS MONTH’S FEATUREThis month, wehave a look attwo famousdenizens ofthe southernsky – Omega[ω] Centauri(NGC 5139),the granddaddyof globularclusters, andCentaurus A(NGC 5128), anearby ‘trainwreck’ galaxythat isthought to bethe result ofthe merger ofa spiral andellipticalgalaxy.

Both are easy to find, especially Omega, which is visible to the nakedeye under a dark sky as a faint ‘star’ with a slightly fuzzyappearance. Centaurus A has reportedly also been glimpsed withoutoptical aid under pristine conditions, but my experience leads me toproclaim this as a superhuman feat; it is, however, easily identifiedthrough a finder ‘scope as a small white haze.

Refer to the following chart; if its orientation is different to whatyou see in the sky, the easily recognisable star patterns it containsshould allow you to relate the two views.

All star charts courtesy of StarryNight®ProTM Version 6.4.3/Simulation

Curriculum Corp.

The key to locating any target in the sky is taking the rightapproach, and the right approach in this case is to identify and getyour ‘fill’ of the globular first then use it to find the galaxy.

To find ω Centauri, first identify the Pointers, Alpha Centauri (akaRigil Kentaurus, magnitude -0.3) and Beta Centauri (aka Hadar,magnitude 0.6), the two stars which point, roughly, at the SouthernCross. Construct, in your mind’s eye, a line from Alpha to Beta, then

veer off to the left, as shown in the chart, and look for a fainterstar, Epsilon Centauri(magnitude 2.3). Epsilon is alittle under 1¾ times as farfrom Beta as Beta is fromAlpha.

Now construct another line,from Beta to Epsilon, andextend it straight out bymarginally less than its ownlength; there you’ll see aneven fainter ‘star’ – that staris no star, it’s OmegaCentauri, a globular cluster containing as many as 10 million stars(estimates vary). Target this area through your finder ‘scope and youcan’t miss the globular; Blind Freddy would be struck by itsprominence! I personally never tire of pointing out a naked eye viewof Omega to newcomers, then waiting for their gasps of amazement asthe faint ‘star’ they have just seen resolves into a huge sphericalball of stars through the eyepiece of the telescope. This image,sourced via Wikipedia, is a closeapproximation to what I see through my‘scope ►

When you’re ready to move on, referback to the preceding overview chart.As it shows, if you reconstruct thelast line we used, from Epsilon toOmega, then veer slightly to the leftas shown and continue by the originalAlpha-Beta distance, you’ll land onCentaurus A. Once again, target this area with your finder ‘scope;look closely for a white haze, smaller and much fainter than theglobular viewed previously. As you won’t have the luxury of being ableto see exactly where it is with the naked eye, it will be a littlemore difficult to locate than Omega, but if you carefully pan aroundthe area indicated, you’ll find it.

A neat trick is to put Omega at one edge of the field of view of yourfinder ‘scope, which will result in the galaxy being diagonallyopposite at the other edge (this is true of a finder ‘scope whichmagnifies by a factor of ten; if your’s magnifies by seven, theslightly larger field of view will place the galaxy a little insidethe opposite edge).

Once you’ve got it centred in the finder, switch to the main eyepieceand experiment with different magnifications to see which gives themost pleasing view. Once again, this is close to what I see (alsosourced through Wikipedia) ►

A word of caution here, to prevent disappointment: views in the nightsky inevitably benefit from a lack of light pollution (except maybe ofthe Moon and Venus!). This is true of both our targets; even Omega,which is surely one of the grandest sights in the heavens, loses itsimpact if you’re battling against street lights or similar. CentaurusA, in my experience, is particularly susceptible under poor conditions– don’t ruin the occasion by viewing it for the first time under otherthan dark skies!

That’s all we have for this month folks; rug up, head off to yourfavourite dark sky location and tour the heavens. As usual, anyquestions, comments or suggestions are welcome; feel free to contactme via Facebook at:www.facebook.com/wayne.roberts.7796or email:[email protected]

Until next month:

CLEARSKIES and

HAPPYHUNTING