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Copy of december 2011.pub - Lazyfish Technology

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December 2011 Kangaroo Valley Voice www.kangaroovalley.nsw.au Page 48<br />

Star struck<br />

By Gerard Keyser<br />

Well, once again I am apologising to my<br />

editor and also to my adoring public (ha ha)<br />

as I missed the editorial deadline two<br />

months running.<br />

Thankfully we’ve had some pretty ordinary<br />

weather for viewing so I don’t feel too guilty.<br />

It’s quite common for the onset <strong>of</strong> the<br />

‘monsoon’ or wet season further north <strong>of</strong> us to<br />

bring unsettled conditions and truthfully<br />

daylight savings pushes me to the limit as I<br />

wait for the sky to become truly dark around<br />

10 pm.<br />

The hot days create a great deal <strong>of</strong> turbulence<br />

in the upper atmosphere as well with the stars<br />

you can see twinkling like crazy.<br />

For the above reasons I am doing a lot more<br />

observing in the daytime. This may seem silly<br />

for an astronomer but the nearest star to the<br />

Earth is our own Sun and it is a very active and<br />

immediate target. A word <strong>of</strong> caution here:<br />

NEVER LOOK AT THE SUN WITH ANY<br />

OPTICAL EQUIPMENT OR EVEN YOUR<br />

NAKED EYE. Permanent damage can be<br />

caused to your vision.<br />

I will explain how to do some basic solar<br />

astronomy later in the article. I have two small<br />

telescopes that are both pr<strong>of</strong>essionally filtered<br />

for safe solar viewing and as they are mounted<br />

side by side I can alternate my study easily.<br />

One telescope has a full aperture white light<br />

solar filter and with this I view sunspots, the<br />

other is optimised to show only one<br />

wavelength <strong>of</strong> hydrogen light, the Hydrogen<br />

alpha spectrum. Both allow through only 0.01%<br />

<strong>of</strong> the Sun’s light and heat. The Hα telescope<br />

allows me to see “surface” phenomena such as<br />

spicules, granulation, sunspots, solar flares and<br />

prominences, and occasionally a CME (coronal<br />

mass ejection).<br />

Two solar scopes mounted side by side and one<br />

confused astronomer at the ready<br />

Most <strong>of</strong> you would have heard <strong>of</strong> the sunspot<br />

cycle, in which the numbers <strong>of</strong> dark shadowed<br />

“spots” on the surface <strong>of</strong> the Sun appear to wax<br />

and wane over an eleven year period. Sunspots<br />

are areas <strong>of</strong> flux in the solar magnetic field and<br />

sunspot activity has <strong>of</strong>ten been closely linked to<br />

long term weather patterns. The jury is still out<br />

in the scientific<br />

community as to the<br />

strength <strong>of</strong> the link<br />

but one type <strong>of</strong> solar<br />

phenomena that<br />

definitely affects us<br />

is a coronal mass<br />

ejection or CME. A<br />

coronal mass<br />

ejection is a large<br />

burst or bubble <strong>of</strong><br />

light energy and<br />

plasma interwoven<br />

with erratic magnetic field lines that appears to<br />

eject from the Sun’s surface in a fairly narrow<br />

pathway. They are <strong>of</strong>ten associated with solar<br />

flares. The narrowness <strong>of</strong> the pathway means<br />

two things; the huge burst <strong>of</strong> energy is much<br />

focussed and hence very powerful, somewhat<br />

like a laser, but consequently it has a much<br />

higher chance <strong>of</strong> missing the tiny target <strong>of</strong><br />

Earth than hitting us. The Earth can fit across<br />

the Sun’s equator 126 times and the Sun as<br />

seen from the Earth subtends only ½ degree,<br />

divide that by 126 and the Earth from the Sun<br />

would be practically invisible. Solar observing<br />

satellites are detecting these phenomena<br />

around the clock as a large CME that appears<br />

to be heading for the Earth can cause damaging<br />

issues with satellite communication and<br />

electrical grids. We are fairly well protected by<br />

the Earth’s atmosphere and magnetic field but<br />

satellites must be turned so their sensitive<br />

communications equipment is not exposed to<br />

these huge bursts <strong>of</strong> energy.<br />

I was able to view a large solar flare in<br />

My observing notes and sketch <strong>of</strong> this<br />

enormous solar flare appear here with<br />

enlargement drawn on the left<br />

PUBLIC NOTICE<br />

The National Parks and Wildlife Service (now a Division <strong>of</strong><br />

the Dept <strong>of</strong> Environment, Climate Change and Water) are<br />

conducting a 1080 fox baiting program in the Kangaroo<br />

Valley and Budgong areas for the protection <strong>of</strong> the<br />

Endangered Brush-tailed Rock-wallaby.<br />

The baiting is conducted on various private properties,<br />

NPWS estate, Sydney Catchment Authority estate<br />

and vacant Crown land.<br />

All bait stations in this program are permanently baited<br />

throughout the year and all properties being baited have<br />

baiting notification signs at their entrances<br />

with the dates when baits are out.<br />

Dog owners are reminded to ensure their dogs do not<br />

wander as dogs are highly susceptible to 1080 poisoning.<br />

For any further information please contact<br />

Melinda Norton or Alison Prentice at the<br />

DECCW Highlands Area Office, Fitzroy Falls<br />

on (02) 4887 8244.<br />

hydrogen light this month but it was pointed a<br />

healthy ninety degrees away from the Earth.<br />

The flare appeared to be about one fifth the<br />

diameter <strong>of</strong> the Sun or roughly 300,000 klms<br />

long! These phenomena can only be observed<br />

in hydrogen light.<br />

Viewing at home: Those <strong>of</strong> us that do not<br />

have access to correctly fitted solar filters can<br />

look at the image <strong>of</strong> the Sun and sunspots by<br />

projecting it onto a large white piece <strong>of</strong><br />

cardboard. Do not uncover any finderscope and<br />

never look along the tube <strong>of</strong> the scope. You<br />

can point your scope by watching the tubes<br />

shadow on the ground. Once you find the<br />

image <strong>of</strong> the Sun, focus the eyepiece and you<br />

will be astonished at the clarity <strong>of</strong> the picture.<br />

Do not do this for long periods as all optics<br />

will suffer from the intense heat generated.<br />

Projecting<br />

the Sun’s<br />

image<br />

(Continued on page 58)

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