Angular separation of two sky positions

Description

angSep calculates the angular separation of two sky positions using spherical trigonometry.

Usage

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angSep(ra1, dec1, ra2, dec2)

Arguments

ra1

Right ascention (string) of the first position.

dec1

Declination of (string) the first position.

ra2

Right ascention (string) the second position.

dec2

Declination of (string) the second position.

Details

Enter positions as text strings with fields separated by characters d, h, m, s, a colon, or a comma, e.g. '17, 42, 28', '-28h43m03s', or '- 28 :43 : 3'. Spaces are removed in input conversion. This is a spherical trigonometry calculation, valid for small and large distances.

Value

Returns angluar separation in decimal degrees.

Author(s)

Andrew Harris

See Also

See dms2rad, hms2rad for input conversions.

Examples

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angSep('1, 59, 03', '-3, 40, 44', '2, 30', '5, 40, 03')
angSep('1h59m03s', '-3d40m44s', '2h30', '5h40m03')
angSep('1', '0', '2', '0')
angSep('   1,  40,  4', '  -  5, 6', '3', '1')