John Pritchard
On clear nights at Mount John, Lake Tekapo, in the middle of the South Island of New Zealand the work of astronomers usually begins several hours before sunset. Today's modern equipement usually requires preparation in some way or another and this work can often be done before it gets dark, thereby saving every precious minute of darkness for actually observing stars.
These `pre-dark' preparations usually turn out to be relatively straight
forward although somewhat time consuming. For the Charge-Coupled-Device
(or CCD) camera it is simply a matter of filling the container which holds
the camera with liquid Nitrogen, a cooling fluid which will keep the camera
at -110
C all night, and checking that the camera is
opperating correctly and will produce the best possible pictures it can.
These things done, it's time to observe stars, but for this of course
it must be dark. While one waits, there is perhaps time to take a few
moments to watch the sun sink slowly behind the Southern Alps to the
west. It's an enchanting view, but the first stars to appear before your
eyes quickly remind you there is a telescope waiting for you, and what's
more, it can show you far more than you could ever hope to see with your
bare eyes.
So into the dome where the telescope waits. Push a few buttons and the motors begin to hum telling you the telescope is ready to be pointed and that it will then faithfully follow whichever star you point it at, all night if need be, as the star traces its arc across the sky. You check your lists and your charts, your first star for the night, a brilliant Blue Super Giant, 300 times the size of or own sun, or perhaps a faint White Dwarf as massive as the sun but only the size of the earth. Pushing some more buttons brings the telescope to life. It sweeps its gaze across the vault of the sky, until finally, this one special star, amongst the billions in our galaxy alone, is in the center of view. So now you unleash the powers of all the modern technology at your finger tips, probing the secrets of this star. In a matter of seconds if the star is quite bright, or perhaps twenty minutes later if the star is rather faint, the camera will have finished acquiring its picture and you will be able to see it almost immediately on the computer monitor. Later analysis with powerful computers will be needed to glean all the infomation from the image. In the meantime it's time to observe another star or perhaps the same one again, depending on your current project.
When dawn finally comes, it's time to turn off the telescopes motors, close the observatory up, and climb into the welcoming comfort of bed to sleep away the day, in preparation for the next night.
In the middle of winter, the nights are long, the sun sets at about 5:00 pm and does not return until perhaps 7:30am, and of course on top of a mountain in the middle of the South Island of New Zealand, it's bitterly cold and one must constantly be warery of the possibility that it could start snowing at almost any minute, pretty yes, but not so good for telescopes! But these long cold nights have their advantages as well. So many hours of darkness allow many observations to be made so it is possible to observe many stars in one night. And the coldness means the nights are often very still and therefore ideal for observing.
In the summer on the other hand, there are only perhaps six hours of darkness, but its warm enough all night for shorts and tee-shirts! On these nights, unless one is observing just one or two stars all night, it is a constant race from one star to another, trying desperatley to observe as many stars as possible before the sun returns to light the skies and hide the stars in its immense brilliance.
It is a little unfortuante that technology is so advanced since it means that most of the work of astronomy is now reduced to working with computers, but each new star requires a final check using ones own eyes, just to be certain the computer really does know what it is doing. These are perhaps the best times, when you gaze out upon the heavens in all their splendour and perhaps imagine yourself reaching out to touch the sparkling gems, or perhaps ponder what eyes might be looking straight back at you on worlds so far from our own.