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Thursday, March 3, 2011

Some excellent (free) star charts

These are from the astronomy department of the Stephen F Austin State University in Texas. They are, typical of star charts produced for astronomers, labeled in Right Ascension instead of Sidereal Hour Angle. This just means that each "hour" is really 15° of SHA, going westward rather than eastward. So starting at the First Point of Aries (0 hours RA and 0° SHA), go 1 hour earlier to "23h". Re-label this "15°". Re-label "22h" to "30°", "21h" to "45°", and so on all the way to "1h" becoming "350°". Declination is exactly the same for astronomers and for navigators, so there's no need to change anything.

Here are the pdfs:

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