How to Use an Astronomers' Map

An astronomers' map is a vital tool for anyone who wants to be a stargazer. An astronomers' map includes a wide variety of observable objects that can be seen using a telescope or a pair of astronomer's binoculars. Astronomers' maps are offered in paper versions as well as online or as part of an astronomer's software suite. Using an astronomers' map is simple once you understand the equatorial coordinate system. The equatorial coordinate system makes it possible to observe objects in three dimensions, as if looking up from the center of the Earth to the surface.

Difficulty: Easy

Instructions

Things You'll Need:

• Astronomers' map
• Telescope or astronomers' binoculars

Use an Astronomers' Map

1. Install and run your astronomy software (follow the directions as provided by the software).

2. Enter the name of an object you wish to observe ('Crab Nebula,' for example) into the software's search engine.

3. Choose the appropriate astronomical entry once a list of potential objects are displayed and click on its name.

4. Write down the coordinates provided on a piece of paper or simply keep your computer on as you begin to calibrate your telescope. Coordinates are listed with the parameters 'Right Ascension' and 'Declination.' Right ascension refers to an object's position in the sky from left to right, while declination refers to its position up or down in relationship to the horizon.

5. Adjust your telescope to point in the direction of the object. Be aware that right ascension tracks left across the sky, contrary to what its name suggests (the higher in degrees, the further left the object is).

6. Note that some astronomy software is capable of being directly linked to your telescope, and can therefore properly calibrate the telescope for you. You can simply click on an object in the database or as part of an interactive astronomers' map, and the software will do the rest.

7. Use a paper map when you don't have direct access to a computer. It's still possible to find a wide range of objects in the sky with a good enough map. Most maps have a legend along the edge that includes the names of some of the more popular sights, and you can determine its position using the gridlines drawn onto the map (similar the lines of longitude and latitude you'd find on a map of the Earth).

Tips & Warnings

• Use red light or turn your astronomy software onto night mode in order to prevent hindering your eye's natural night vision. Using flashlights or other white light generators will make your eyes constantly adjust and readjust.
• Don't use a telescope or binoculars to look at the sun. The sun will cause severe damage to your eye when observed through magnifying instruments.

Resources

• Telescopes and astronomers' maps at Telescopes.com