Orion 7880 instruction manual Locating Stars, Named Stars, Double and Multiple Stars

7. Locating Stars

The IntelliScope database contains 837 stars. Stars always appear like tiny points of light. Even powerful telescopes cannot magnify a star to appear as more than a point of light! You can, however, enjoy the different colors of the stars and locate many pretty double and multiple stars. You can also monitor variable stars from night to night to see how their brightness changes over time.

To view a star, press the Star button on the controller. The LCD screen will then display the word “STAR” with the word “NAMED” flashing next to it. From this screen, use the arrow buttons to choose from “NAMED,” “DOUBLE,” “VARIABLE,” and “CATALOG.”

Named Stars

The named stars are the brightest in the night sky. These are the stars that the ancients gave proper names to, like “Arcturus” or “Mizar.”

To select a named star, press Enter after selecting “NAMED” from theStar button choic- es. You can now use the arrow buttons to scroll through the list of named stars. The stars are listed in alphabetical order. Once you have found the named star you would like to observe, the guide arrows will direct you to move the telescope to the star’s position. The upper left corner of the LCD screen will show the named star’s ST catalog number (the IntelliScope’s entire ST catalog is printed in Appendix D for easy reference), and the lower left shows the constellation in which the star resides. Pressing Enter again will dis- play the star’s R.A. and Dec. coordinates, its magnitude, and a brief description.

To find another named star to observe, simply continue scrolling through the list of named stars.

Double (and Multiple) Stars

Many stars in the night sky appear to be single stars, but they are not. They are actually double or multiple star systems. Some of these systems comprise two or more stars grav- itationally bound to each other, while others are just two (or more) stars in the same line of sight. At high magnifications, it is possible to “split” many double (and multiple) stars into their individual components. It can also be interesting to contrast and compare the different colors and magnitudes of the stars in the system. Be aware, however, that good seeing conditions are critical for separating close components of a double or multiple star.

To select a double (or multiple) star to observe, press Enter after selecting “DOUBLE” from the Star button choices. The LCD screen will then display the word “DOUBLE” with a flashing three- letter constellation designation after it. Now, select the constellation in which you would like to view a double star. Use the arrow buttons to scroll through the list of constellations. If you are unsure which constellation the three-letter designation repre- sents, refer to Appendix C. Once you have selected the constellation, press Enter. A dou- ble star in that constellation will now appear on the LCD screen, along with the guide arrows to lead you to the double star. The current constellation is shown in the lower left, and the double star’s name is in the lower right.

Note: Double stars typically have names like “Zeta” (Greek letter designation) or a num- ber like “36” (Flamsteed number). The full names for these double stars are actually linked to the constellation they reside in. For example, in the constellation Andromeda, these stars would be “Zeta And” and “36 And.”

For more information about the double star selected, press the Enter button. (The “S=” now refers to the separation, in arc-seconds, between the double stars. For multiple stars,

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