Objects in the Night Sky
Finding objects in the night sky depends on three factors: Knowledge, Memory and Availability; a working knowledge of what’s up in the sky, an ongoing accumulative memory of where and when objects are seen and what planets and stars are available for the viewing night.
Fortunately, our changing night sky is accurately mapped and if we start with learning the shapes of constellations and the names of key stars we have a good idea of the general area where we are searching for an object. Maps and Star Atlases go deeper and we move into a more detailed search area. As we develop this skill, we learn to orientate maps for latitude and time of night and we soon find that star hopping becomes easier. The trick is to use a map suitable to our present skill. It helps to set ourselves tasks such as learning key noteworthy objects in whatever constellations are on display at the time of viewing. I find that keeping notes can help for later viewing sessions and they bring great pleasure in future times.
I have often used the analogy of street maps in strange cities: we start with a familiar street and work from there. Most beginners are familiar with three basic constellations: The Southern Cross, Orion and The Scorpion. These three groups alone can lead us out to nearby groups and so on until all but the most obscure areas in the sky become familiar. Ongoing familiarity with the monthly and annual movements of the planets, thanks to the Year Book, should soon make us familiar with what planets are visible and when.
You will suddenly feel it worthwhile learning the basic constellations when the cry goes up: “There is a new comet in Sextans.” Or, “ A nova has suddenly appeared in Caelum.” You will also know not to get out a telescope when you learn that Comet Turner/Johnson is breaking up and reaching naked eye brightness in Perseus.
Using Maps and Guides
All maps and guides to the sky are limited and rely on practice, commonsense and a great deal of imagination to benefit the viewer. While guide books depicting individual constellations and the deep sky wonders of each can be useful, it is often the case that the most interesting objects exist in an empty corner of a constellation, which in itself is orientated for the northern viewer. However, having said that, a guide to the constellations, such as Collins: ‘Guide to Stars and Planets’ is useful for getting to know some basic Deep Sky Objects and especially for learning the shapes and positions of the constellations.
Sky maps range from simple maps and atlases to the pricey and complex Millennium Star Atlas, which comes in three volumes. These atlases are great to study indoors but often prove awkward outdoors at the telescope and are subject to deterioration. Many observers have now the computer programs and skills necessary to print adequate maps that can be taken outside and written on. A serious drawback is the limited sky covered by detailed maps and the observer is confined to only those parts of the sky on the printed sheets.
A compromise is the series of Sky Map 2000 which comes in both an atlas and individual large maps which have great variation in presentation, such as white stars on a dark sky or black stars on a white sky and lamination’s to overcome dew and weather. These are very useful but require a large table to use.
The best and most useful mapping system I have seen and used is the Sky and Telescope’s ‘Pocket Sky Atlas,’ by Roger Sinnot. This is an impressive, well laid out and clear set of maps, covering great detail, 1,500 deep sky objects and stars to mag. 7.8 and beyond in some select maps. Avoid maps that are too detailed as a beginner.
When I first started viewing I found a small handbook detailing a selection of easily viewed objects from each constellation with an accompanying map very useful.