will then cycle information about the object you are viewing such as its celestial coordinates (R.A. and Dec.), magnitude (brightness), size (in arc-minutes or arc-seconds), and a brief scrolling text description.
When you are finished viewing the selected NGC object, you may scroll to another NGC object by using the arrow buttons, or you can select another NGC object to view by pressing the NGC button again.
The Index Catalog
The Index Catalog, or IC, contains 5,386 objects discovered in the decade or so after the NGC catalog was first published. This list contains objects similar to the NGC, but IC objects are typically fainter and more difficult to observe.
To view an object from the IC catalog, press the IC button. Then input the number of the IC object you wish to view using the numeric buttons and press the Enter button. For example, to view the Flaming Star Nebula, which is listed as IC405, you would press the IC button, then the “4” button, then the “0” button, then the “5” button, followed by the Enter button. If the number of the IC object you wish to view contains four digits, it is not necessary to press Enter after inputting the fourth digit.
The object’s catalog designation will be shown in the upper left corner of the LCD screen, with the guide arrows in the upper right. The lower left will show the constellation the object resides in, and the object’s common name (if it has one) or a brief description of the object will be shown in the lower right. Move the telescope in the corresponding directions shown by the guide arrows.
You can get more information about the selected object by pressing the Enter button. The second line of the LCD display will then cycle information about the object you are viewing such as its celestial coordinates (R.A. and Dec.), magnitude (brightness), size (in arc-minutes or arc-seconds), and a brief scrolling text description.
When you are finished viewing the selected IC object, you may scroll to another IC object by using the arrow buttons, or you can select another IC object to view by pressing the IC button again.
E. Locating Deep Sky Objects by Object Type Rather than trying to select objects by catalog numbers, you may wish to simply view certain types of objects. This is where the Nebula, Galaxy, and Cluster buttons come in handy. These buttons will access a selection of the best and brightest nebu- las, galaxies, and star clusters in the night sky.
The Nebula, Cluster and Galaxy buttons are organized by constellation. So, before using these buttons, decide in which constellation you would like to view an object. Choose a con- stellation that is at least 40˚ high in the sky to get a good view. If you are unsure of the constellations currently visible in your night sky, consult a planisphere or the monthly star chart at www.oriontelescopes.com.
Locating Nebulas
Amongst the most beautiful objects in the night sky, nebu- las are clouds of dust and gas that are lit by a nearby stellar source. There are several different types of nebulas; emission
nebulas, which are where star systems form, planetary nebu- las, which are the result of a star dying, and reflection nebulas, which are caused by dust reflecting starlight. Most have low surface brightness, so a dark sky free of light-pollution is best for a night of viewing nebulas.
To view a nebula, press the Nebula button on the controller.The LCD screen will then display the word “NEBULA” with a flash- ing three-letter constellation designation after it. Now, select the constellation in which you would like to view a nebula. Use the arrow buttons to scroll through the list of constellations. If you are unsure which constellation the three-letter designation represents, refer to Appendix E. Once you have selected the constellation, press Enter. A nebula in that constellation will now appear on the LCD screen, along with the guide arrows to lead you to the nebula. The current constellation is shown in the lower left, and the nebula’s proper name or catalog number is in the lower right. For more information about the nebula selected, press the Enter button.
To go to the next nebula in the selected constellation, simply press the up arrow button. The guide arrows will now direct you to the next nebula in the constellation. If there are no more nebulas available in that constellation, a nebula from the next constellation (in alphabetical order) will be displayed. To select another constellation in which to view nebulas, press the Nebula button again.
Locating Star Clusters
Star clusters are just what their name implies; groupings of stars. Star clusters come in two main types, open and globular. Open star clusters reside within our Milky Way galaxy and usu- ally contain a handful of stars clustered together because they were spawned from the same gas cloud. Globular clusters are more like miniature galaxies, with hundreds or thousands of stars packed into a spherical shape by mutual gravity. Globular clusters reside outside the disk of the Milky Way galaxy and orbit the galaxy’s center. It is believed that globular clusters are formed as a natural consequence of galaxy formation. Star clusters, in general, are somewhat bright compared to other deep-sky objects, so many will appear quite spectacular, even in smaller telescopes.
To view a star cluster, press the Cluster button on the controller. The LCD screen will then display the word “STAR CLUSTER” with a flashing three-letter constellation designation after it. Now, select the constellation in which you would like to view a star cluster. Use the arrow buttons to scroll through the list of constellations. If you are unsure which constellation the three- letter designation represents, refer to Appendix E. Once you have selected the constellation, press Enter. A star cluster in that constellation will now appear on the LCD screen, along with the guide arrows to lead you to the star cluster. The cur- rent constellation is shown in the lower left, and the star clus- ter’s proper name or catalog number is in the lower right. For more information about the star cluster selected, press the Enter button.
To go to the next star cluster in the selected constellation, sim- ply press the up arrow button. The guide arrows will now direct you to the next star cluster in the constellation. If there are no more star clusters available in that constellation, a star cluster
