STEPHENHAWKING A BRIEF HISTORY AT 75
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£4.99 January 2017
PLUTO’S DISCOVERER REMEMBERED • MYSTERIOUS DARK ENERGYHOT PRODUCTS FOR 2017 • NIGHT SKY SIGHTS YOU MUST SEE THIS YEAR
POLE STAR PUBLICATIONS
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ASTRONOMYMAGAZINE
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January 2017 | Astronomy Now | 5
CONTENTS
56 CLYDE TOMBAUGH
One of the great American astronomers of the 20th-century, the man who discovered Pluto, died 20 years ago. We look back at his career.
100 COMET 29P/SW1
Comet Schwassmann–Wachmann 1 shows intriging and complex behaviour that amateur observations are helping to unravel.
48 DARK ENERGY
The Universe is expanding at an accelerating rate. We look at supernovae’s role in modelling the elusive force astronomer’s believe is responsible.
58 HOT PRODUCTS FOR 2017
Check out what astro gear is likely to be in big demand.
STEPHENHAWKING A BRIEF HISTORY AT 75
ASTR
ON
OM
Y N
OW
JAN
UA
RY 2017 • STEP
HEN
HA
WK
ING
• CLY
DE TO
MB
AU
GH
• DA
RK
ENER
GY
VO
L 31 NO
1
£4.99 January 2017
PLUTO’S DISCOVERER REMEMBERED • MYSTERIOUS DARK ENERGYHOT PRODUCTS FOR 2017 • NIGHT SKY SIGHTS YOU MUST SEE THIS YEAR
POLE STAR PUBLICATIONS
THE UK’SBIGGEST
ASTRONOMY MAGAZINE
FREE INSIDE: SATURN POSTER & YEARPLANNER
001_cover_jan17_FIN.indd 1 05/12/2016 17:31
COVER The spotlight is on Stephen Hawking as he celebrates his 75th birthday on 8 January. Image of Stephen Hawking: Max Alexander/Starmus.
92 THE UNIVERSE FOR BEGINNERSSpace Telescopes such as Hubble, Kepler, Chandra and Hipparcos have made a huge impact in our understanding of the Universe.
110 REVIEWEDFirst Contact’s optic-cleaning kit and Vixen’s high-end refractor.
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112 | Astronomy Now | January 2017
EQUIPMENT REVIEWIN THE SHOPS
Keeping your precious optics clean is crucial to maintain optimal performance. First
Contact’s hands-free cleaning solution might be just what you need to
rejuvenate that dirty mirror. Steve Ringwood finds out.
First Contact polymer cleaning
KIT REVIEWASTRO
At a Glance
First ContactManufacturer: Photonic Cleaning Technologies, LLC
Details:www.photoniccleaning.comFirst Contact comes in (legacy) clear polymer and new red polymer
Current UK suppliers:
365Astronomy: details at www.365astronomy.com/ Stanwax Laser: details at//shop.stanwaxlaser.co.uk/Price: Various kits, from £93
Cleaning optics is fraught with danger. Even the softest of strokes with a camel’s hair brush may drag an unseen microscopic boulder across a finely crafted sub-wavelength sheen,
inflicting a groove of Grand Canyon proportions, relatively. Or it may deposit a sticky fibre-grabbing oil slick sourced from your finger’s sebaceous glands the last time you stroked the brush to enjoy its silky feel. Consequently, there is a view that unless potatoes are sprouting from surface deposits, it is best to leave well alone. A technology that offers to clinically clean your optics without having to touch them therefore has to be welcomed with both hands (leaving no fingerprints, of course).
Arrival of the box containing the First Contact cleaning materials could not have been more
timely. Following a house move a year earlier, I had at last taken delivery of a shiny new observatory – meaning that hundreds of optical items were blinkingly re-emerging from their enforced hibernation in dusty removals boxes and required tender loving cleaning. A more challenging task for this product is hard to imagine. Liquid polymer cleanEssentially, First Contact is a liquid polymer that is deposited onto a lens or mirror (via a spray, dropper or brush). During the deposition, it envelopes every tiny fragment of dust, fibre and microscopic particle that has made its home there. Once the polymer has cured, it is peeled off as a sheet, taking all surface deposits with it – leaving behind a substrate as clean and perfect as the day it was formed. That, at least, is the theory. With a plentiful supply of optics simply begging to be unladen of their grime, the polymer and I set to work.
The first item to undergo liberation was the object glass of my precious 5.25-inch, f/14 refractor. This is no ordinary piece of glass. The Fraunhofer-design achromat was made for me in the 1970s by the fair hand of Henry Wildey, an optician of no mean repute. Internally it was fine, but the outer surface was powdered grey with muck. Trepedacious? Yes. But I had full confidence that should the experiment result in harm to the telescope, Astronomy Now would happily reimburse me. (Editorial comment here removed.) Sparkling glass!Carefully pouring some of the polymer into one of the supplied spray bottles, I squirted a thin layer of this red liquid onto the glass – ensuring it was universally well covered. Curing time depends on ambient temperature, but it was the next day before I returned to see what had happened. The red fluid had indeed become a solid sheet, so with heart in mouth I
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EQUIPMENT REVIEW IN THE SHOPS
gently tugged the sticky tab supplied for this purpose. Like a sheet of thin polythene, the cured polymer rolled away from the lens as one piece.
What was revealed underneath was nothing short of miraculous! The lens glowed with clarity, sparkling in the afternoon sunlight with not a trace of residue or the filth that had marred its appearance the day before. I had never seen it cleaner in over thirty years of care. And all without touching the glass at all.
Vastly encouraged, I decided that my next victim would be a 50mm Lanthanum eyepiece. I have long used this as the eyepiece of a finderscope, so it has never enjoyed the protection of a nightly return to the accessory case. Consequently, its eye lens was suitably ‘unclean’ and ready for restoration.
This time I used a First Contact bulbed pipette for greater accuracy of the liquid’s placement. This I think should have a smaller exit aperture, for I had expected the fluid to egress only with applied pressure – but once approaching vertical the liquid simply ran through. This initially made a mess, but fortunately not on the eyepiece. (The old habit of working on spread-eagled newspaper serves me well still.) Forewarned, the rest of the application went well.
This time, with the sticky tabs too large for an eyepiece, I had embedded a (dental floss) thread to act as a lifting mechanism. When this was pulled, a nicely cured 40mm disc came away, revealing the same startling results. However, there were still visible the faint traces of ingrained water spots.
Stubborn stains First Contact had thoughtfully included in my parcel an additional fluid (WSP1). This is aimed at just this sort of task – acting as a pre-treatment for the main polymer. With a soft brush, I wiped a few drops of this primer fluid onto the eye lens, then again applied the polymer. Voila! Upon the second removal the lens was literally spotless. Even the multicoating looked fresh.
A small word of warning. Although the fluid is quite gloopy, it is still thin enough to take advantage of osmosis and can drag itself into any crevice – including the edges and retaining rings of lens mounts. Thoughtfully, First Contact include rubber O-rings that can be used as lens-edge ‘barriers’ to shield this undesired flow into an eyepiece’s innards. It does occur to me that perhaps the viscosity of the polymer might be adjusted as an alternative or additional measure; but it may be that the low viscosity is needed, to gobble up all that dirt in its path.
One lesson I did learn was to clean the spray heads after use. Once the polymer cures within them they do not squirt again – until thinner is forced into them. But that problem was entirely down to me – and a helpful hint to others.
Grubby mirror The most severe challenge offered to First Contact was the primary mirror of a 10-inch reflector. Standing on its end, the tube had unfortunately languished unloved in a damp garden shed for about 14 months. Despite my best efforts, it had succumbed to the environment by accumulating a fair bit of debris onto its silvery gravity well. Despite an aluminium coating already in decline and in need of refreshing, it was still a good mirror beneath the muck. Had I not had First Contact to hand, I might well have given it the usual (often unsatisfactory) wash with detergent. But, armed with a bottle or two of this magic red unguent, I decided it should have a go.
The mirror was centred by a collimation marker and, considering how hard it is to place these accurately, I did
The object glass of the author’s beloved but unkempt Wildey refractor. All photographs by the author.
The five-inch lens after deposition of the red First Contact polymer.
Gently does it. Wondering what now lies beneath.
The lens of the five-inch refractor revealed crystal clean.
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114 | Astronomy Now | January 2017
EQUIPMENT REVIEWIN THE SHOPS
not want it to be removed by the cleaner. I therefore protected it with one of the provided O-rings, which encircled it admirably. As the mirror’s dirt was clearly well fastened, I began by administering the WSP1 pre-treatment before spraying on the polymer.
I must say that when the time came to lift the sheet, I was fearing that the ancient aluminium coating would come away too. Ironically, it was not a case of the metal lifting, but the polymer not lifting at all! The sticky tabs pulled off, but not the polymer – which appeared stuck to the mirror’s surface as fast as a lacquer.
Mistake corrected!I was very glad of the excellent support given by Photonic, the manufacturers of First Contact. Closer examination revealed that my enthusiastic application of the cleaner had breached the peripheral bevel of the mirror and coated some of the mirror’s edge. It was this that was providing the polymer with a stubborn streak. I was recommended to embed a piece of the supplied mesh (another lifting tool), and once cured try another lift. The extra purchase this provided worked like a charm and a perfect plasticised red disc peeled off to reveal a lovely clean mirror. Only the tarnishing of the less-than-nominal aluminium remained visible. (I cannot expect even First Contact to re-aluminise a mirror during its cleanse. Perhaps that is already in development?)
This is a super product. Used proficiently, it is an effective ‘no-hands’ optical cleaner ... and clean optics mean more light provided to the observer. Don’t forget that a mere speck of dirt will waylay photons that have laboured millions of years to get to you. Those otherwise innocent but grimy particles can impede fundamental research. Speaking of which, First Contact is employed in keeping clean the optics used in the high-precision LIGO gravity wave detector. If it’s good enough for them, I’m happy to take a piece of that action.
Steve Ringwood is Astronomy Now’s equipment consultant.
Removing the polymer film from the eyepieces.
A mirror reborn – or at least, an expensive re-coating postponed.
The final conflict. The author’s ancient ten-inch primary mirror.
Accurate deposition is possible using the pipette.
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