Star Charts
| Key to the Star charts | |
|---|---|
| Item | Description |
| UPPERCASE TEXT | Constellation names are indicated in uppercase text. |
| Selected star of magnitude 1.5 and brighter. Labeled with common name, star number, and Greek letter to indicate Bayer designation. | |
| Selected star of magnitude 1.6 and fainter. Labeled with common name, star number, and Greek letter to indicate Bayer designation. | |
| Tabulated star of magnitude 2.5 and brighter. Labeled with Greek letter to indicate Bayer designation. | |
| Tabulated star of magnitude 2.6 and fainter. Labeled with Greek letter to indicate Bayer designation. | |
| Untabulated star. Not labeled. | |
| Dotted line | Constellation outline. |
Navigators often use star charts to identify a star by its position relative to other stars. References like the Nautical Almanac and The American Practical Navigator provide four star charts, covering different portions of the celestial sphere. Two of these charts are azimuthal equidistant projections of the north and south poles. The other two cover the equatorial region of the celestial sphere, from the declination of 30° south to 30° north. The two equatorial charts are mercator projections, one for the eastern hemisphere of the celestial sphere and one for the western hemisphere. Note that unlike familiar maps, east is shown to the left and west is shown to the right. With this orientation, the navigator can hold the star chart overhead, and the arrangement of the stars on the chart will resemble the stars in the sky.
In the star charts, constellations are labelled with capital letters and indicated by dotted lines collecting their stars. The 58 selected stars for navigation are shown in blue and labelled with their common name, star number, and a Greek letter to indicate their Bayer designation. The additional 115 tabulated stars that can also be used for navigation are shown in red and labelled with a Greek letter to indicate their Bayer designation. Some additional stars not suitable for navigation are also included on the charts to indicate constellations, they are presented as unlabelled small red dots.
Read more about this topic: List Of Selected Stars For Navigation
Famous quotes containing the words star and/or charts:
“Between us two it’s not a star at all.
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So much is being now expected of....”
—Robert Frost (1874–1963)
“There’s one basic rule you should remember about development charts that will save you countless hours of worry.... The fact that a child passes through a particular developmental stage is always more important than the age of that child when he or she does it. In the long run, it really doesn’t matter whether you learn to walk at ten months or fifteen months—as long as you learn how to walk.”
—Lawrence Kutner (20th century)