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UCAC-3 numbers Off Mag Labels Off Proper Motion vector: Vj (Photometric band) Star saturation: Blurring: The first option is nearly self-explanatory; it provides a way to set the limit Guide goes to in drawing stars at the current level. Some caution is necessary here. If you tell Guide to draw to, say, magnitude 14 at a 180-degree field of view (level 1), it will attempt to do so. But since about 5 million stars will be drawn, it will take a long time and look very messy. The next two options affect how stars are drawn on the screen. They are best understood by trying them. When "Outline Stars" is turned on, dim stars on top of bright stars are bordered in black, making them visible. (Note that this option is not normally used now; the "blurring" option, described below, usually looks better.) When "Color Stars" is turned on, stars are colored by spectral type: red for cool class M stars, blue for hot type O stars, yellow for class G stars such as the Sun, and so forth. "Color Stars on" only has effect for stars for which spectral information is available (this usually means stars brighter than about magnitude 10.) The "Mag Range" and "Star Size" items let you adjust the size of the circles used to display stars. The brightest star visible in Guide (Sirius) is about five million times brighter than the dimmest star visible. This range can't be shown on the monitor. A range of 10 magnitudes (a factor of 10000) is the default, but the "Mag Range" may be set differently. Also, you can set limits as to how large or small a star can be with "Min Star Size" and "Max Star Size". Combined, these three options give you complete control over the relationship between magnitude and dot size. The next ten items all control the display of labels for stars. They cycle from Auto to On, then to Off, then to Auto again: a three way switch. When a marking is on On or Off, Guide will ignore its own judgment and either always show or always not show the marking. When it is on "Auto", Guide uses a predetermined set of rules designed to minimize clutter. "Mag Labels" labels all stars, down to the indicated brightness level, by magnitude. You might have a chart showing stars down to magnitude 15, but you wouldn't want all of them labelled by magnitude; it would be too crowded. So you would set a limit of (perhaps) magnitude 11 here. If you set a "proper motion vector" length of, for example, 1000 years, each star will appear with a short line indicating the direction
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