How to Locate a Deep Sky Object

A deep sky object is a compact field of stars, gas or another galaxy. Astronomers did not know what they were when telescopes were first turned to the heavens. Photography and other imaging tools have helped us learn more about these interesting sights in the sky.

Instructions

Difficulty: Moderately challenging

Things You’ll Need:

• Insect Repellents
• Warm Clothes
• Telescopes
• Sky And Telescope Subscriptions
• Telescope Eyepieces
• Star Charts
• Lawn Chairs
• Telescope Flashlights

Using the Naked Eye and Binoculars

1. Go to a place that is well away from city lights (over 60 miles away is best) and that has no direct lights nearby. You can see some of the deep sky objects with your naked eye if you are in a dark enough place.
2. Allow 15 minutes or more after stepping out of a lit area for your eyes to adapt.
3. Look for the Milky Way galaxy during the evening hours. It will extend across the sky through the constellations of Cygnus and Sagittarius during the summer months and through Auriga and above Orion in the winter months.
4. Use a star chart to locate some of the bright constellations listed below. You should be able to see some of these objects using the naked eye and a set of binoculars.
5. Find Orion in winter. Under the belt of Orion (three stars near the middle) is the sword. The fuzzy bright area of the sword is the M42 Orion Nebula. The Pleiades (Seven Sisters) are an open cluster, as is the cluster of stars near the head of Taurus the Bull.
6. Find Hercules in spring. Under the eastern shoulder is M13. It will appear as a fuzzy star. This is a globular cluster of over a million stars.
7. Locate Sagittarius in summer. Above the teapot shape of this constellation are two emission nebulae numbered M8 and M20.
8. Locate Andromeda near Pegasus in the autumn. The fuzzy area near the center of Andromeda is the famed M31 Galaxy.

Using a Telescope

9. Use your binoculars or finder scope to locate the object before using your telescope. Again, the darker the observing location, the better.
10. Start by locating, near the deep sky object, a star that can be seen in the finder telescope.
11. Use a detailed chart of the stars and move from the brighter star to the dimmer stars matching the patterns in the charts until you reach the area of the deep sky object.
12. Look around the edge of the eyepiece but pay attention to what is seen by the corner of your eye. Sometimes you will see the object out of the corner of your eye only, and when you try to focus directly on it, you cannot see it. This is called averted vision. The light receptors toward the outside of your normal vision field are better at picking up dim objects.
13. Look for the target deep sky object with minimal magnification. The largest diameter eyepiece will produce the lowest magnification. If you have a 1-inch and a 1/2-inch eyepiece, use the 1-inch one to locate the object.
14. Start with the brightest deep sky objects first. Deep sky objects often appear as fuzzy stars or diffuse areas. It is easy to glance past them until your eye becomes trained on what to spot.
15. Try higher magnification for some objects after finding them. Most planetary nebulae are best seen with high magnification. Larger objects such as galaxies and clusters are often best seen with lower magnification eyepieces.
16. Don't expect the object to appear as it does in photographs. Deep sky objects are diffuse and dim to the eye. There will be no color visible except in the very largest of telescopes. You won't see deep red or bright blue as many photographs show.

Tips & Warnings

• These brighter objects are located on maps of the sky as found in publications such as "Sky and Telescope" and "Astronomy." Other charts such as "Norton's Star Atlas" will also show these objects relative to the brighter stars.
• Light-polluted sky conditions will result in the deep sky object being lost against the background light. It will be washed out, and you will not be able to see it very well or not at all.
• Obtain a good star chart or atlas that lists bright stars and deep sky objects.
• The larger the telescope, the better - an 8-inch or larger telescope is recommended.
• Use a red-covered or red-lit flashlight for reading the star chart.