Page 88 - All About Space 68 - 2017 UK

STARGAZER

How to… Tips & tricks

Observe Neptune Acquire a star chart

A star map is a really useful aid to
finding Neptune. At opposition, the
planet will be in Aquarius – if you see a
'star' that’s not in the constellation on
The remote ice giant comes to opposition this September, the chart, that'll be the ice giant.

making it suitable for observation. The planet will still be a Know your field of view
challenge, so here are some tips on the best ways to see it… It's useful to be familiar with the field
of view of your telescope under the
eyepiece you are using. This will assist
with pinpointing Neptune.
the case for Neptune, the eighth and Adams, making it a joint German/ Use a blue/green filter
You’ll need: farthest-known planet in our Solar French/British achievement. Until this Using a coloured filter – a blue/green
✔ At least a medium- System which lies on the inner edge of time it hadn't been noticed, as it is one is useful – will help increase the
contrast to make resolving the ice
sized telescope the Kuiper Belt. so faint and certainly not a naked giant’s disc effortless.
It is a 'gas giant' planet, not dissimilar eye object.
✔ Star chart to Jupiter, Saturn and Uranus. It is, Even at opposition it will only be 2.4 Start off with a
✔ Coloured filters however, much colder as it is so far arc-seconds in diameter, but obviously suitable magnification
(optional) from the Sun. The gas from which the not a star. Once you have acquired it Use a ‘power’, which allows you to
planet is made is in a frozen state. The in your telescope, it will look like a identify the stars on your chart with
When a planet comes to 'opposition', type and make-up of the gas gives the tiny bluish disc. If conditions allow, what you see. In order to fit many stars
it means that it is opposite the Sun planet a strong blue tinge, which is increase the magnification you are into your field of view, you’ll need a low-
– from our point of view – in the visible even in amateur telescopes. The using to show it well. A coloured power eyepiece.
sky. To be in this position, the Earth planet is, however, fairly featureless filter can help enhance the view too;
must be between the planet and the except for the ‘Great Dark Spot’ and the it's worth experimenting here. The Up the magnification
Once you've found the planet, up the
Sun, which in turn means that we accompanying ‘bright smudge’, which joy in observing this amazing world
are relatively close to the planet in aren’t visible in amateur scopes. is remembering the vast distance power to see it properly as a small
bluish disc. The lower the aperture of
question (as much as our respective The pleasure in observing Neptune between Earth and Neptune – a whole your eyepiece, the higher the power.
orbits around the Sun will allow is drawn from the fact that we can see 4.2 billion kilometres (2.6 billion miles).
anyway). Because we are closer to it at all, considering it wasn't discovered This great distance means that it has Finding the distant
another planet at this time, it will until 1846 by a German called Galle, taken the light from the planet over ice giant in Aquarius
appear as large as it possibly can to based on the mathematical work of a four hours to reach us! Make the most Finding Neptune can be tricky, but once
us in terms of its diameter. At the Frenchman called Urbain Le Verrier of your chance to view the last large you've got it, it will be obvious it's not a
beginning of September, this will be and an Englishman called John Couch- planet in our Solar System. star. Follow our steps to make it easy.

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