lightfossils.co.nz

The Objects we image are visible from Wanaka at different times of the year. Some objects that are in the Southern part of the Sky near the South Celestial pole are not visible from the large areas of the Northern Hemisphere, other objects such as the Great Orion nebula are.

Galaxies such as our own Milkyway Galaxy are made up of billions (yes, that is right) stars. They of course emit their own light that we trap. These targets are extraordinarily long distances away, as in tens of millions of light years.

Pause for a moment, in NGC 300 below, we can see a vast number (something in excess of a billion) stars, we can also see a number of other faint galaxies in the background. These other galaxies also have vast numbers of stars in them. We now know from recent exoplanet hunting projects that planets form as a normal part of star formation, so it is reasonable to conclude that for the stars you can see there will be more planets around them that you can't ....

Other targets called nebula emit light from gas that is excited, Hydrogen emits reddish pink light, Oxygen blue and so on. So the glowing nebula targets you see here are emitting their own light, and mostly are in our galaxy.

Dark or reflection Nebula are areas of clouds not too dissimilar to smoke, basically enormous clouds of carboniferous dusty smoke that is then lit, or back lit by stars.

You will notice that a number of our images include galaxies, emission nebula and reflection nebula as well.

How we capture the photons is both simple and complex. Simple in the sense that putting a camera chip at the end of a telescope. Complex in the sense of these things that we have to overcome to produce an image.

Because the light has travelled so far it is naturally faint, just like any energy that radiates outward from a point source, the further from the point source the less intense or dense the photons are. To overcome this we need to point our telescope at precisely the same piece of sky for long periods (hours) to gather enough light to make the photo.

Given the accuracy required that is harder than it sounds, but also during that time the temperature will invariably change, usually it cools as the night progresses.

The problem with temperature is two fold, the warmer your CCD chip in the camera the more noise or "grain" in the photo. That's why we cool our camera chips to well below freezing, to reduce the noise and improve the SNR, or signal to noise ratio. Secondly metal, glass and other materials shrink or contract as you cool them, that changes the focus. These images need to be very accurately focussed so we are constantly refocussing.

The point is, it is a lot more difficult than just pointing a telescope and camera skyward to get these results.

Please enjoy.

NGC 3372 Eta Carinae Nebula Order Ref NGC 3372

This bright nebula is in the Southern sky near the Southern Cross, it is easily seen under dark skies with the naked eye. This nebula lies between 6500 and 10,000 light years away. Eta Carinae, the bright yellowish star to the lower right of center has brightened and dimmed over the years and is expected to super nova at some point in the not too distant future, of course it may have already but we will only know approximately 7600 years after the event when the lightfinally arrives at Earth.