I want to observe double stars, but my Go To telescope needs their SAO numbers. Where can I get them?

gamma andromedae
James Mullaney

SAO numbers come from the Smithsonian Astrophysical Observatory Star Catalog (1966). They aren’t normally used by double-star enthusiasts, who prefer special notations such as ADS 1630, S748, and Krueger 60. Finding equivalent catalog designations can be a nightmare. Your best bet is to point the telescope using the star’s right ascension and declination, which are found in any book on double stars. Most Go To mounts provide a way for you to key in these values directly and then execute a Go To command. While some of the very simplest Go To mounts may not, they can always display the current right ascension and declination. While watching this display, slew the mount until the numbers match the coordinates of your target.

— Dennis di Cicco


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January 1, 2018 at 7:10 pm

SkySafari 5 (iOS) provides SAO numbers for most stars, including doubles.

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July 25, 2018 at 10:15 am

What a very poor answer from Dennis di Cicco. Astronomers with go to telescopes use SAO numbers all the time. The lists for SAO numbers are freely available on the internet, and can be downloaded in the form of pdf or excel spreadsheets which can easily be stored and then used outside at the telescope for very accurate observations. While you can use the right ascension and dec coordinates, it is far easier and more accurate to use SAO numbers. It's very simple and certainly not a nightmare.

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