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Coordinate Commands

Coordinate transformations between astronomical systems.

Commands​

starward coords transform​

Transform coordinates between systems.

# ICRS to Galactic
starward coords transform "12h30m45s +45d30m00s" --to galactic

# Galactic to ICRS
starward coords transform "l=120 b=+30" --to icrs

# To horizontal (requires observer)
starward coords transform "12h30m +45d" --to horizontal --lat 40.7 --lon -74.0

starward coords parse​

Parse and display coordinate formats.

starward coords parse "18h36m56s +38d47m01s"

Supported Systems​

SystemDescriptionFormat
ICRSEquatorial (RA/Dec)12h30m +45d
GalacticGalactic (l/b)l=120 b=+30
HorizontalAlt/AzRequires observer

Coordinate Formats​

starward accepts flexible input formats:

# Sexagesimal
"12h30m45.6s +45d30m15s"
"12:30:45.6 +45:30:15"

# Decimal degrees
"187.5 +45.5"

# Mixed
"12h30m +45.5"

Examples​

# Vega's galactic coordinates
starward coords transform "18h36m56s +38d47m01s" --to galactic

# M31 altitude from New York
starward coords transform "00h42m44s +41d16m09s" --to horizontal \
  --lat 40.7 --lon -74.0

# Verbose transformation
starward coords transform "12h +45d" --to galactic --verbose

Python API​

from starward import ICRSCoord, GalacticCoord

# Parse coordinates
vega = ICRSCoord.parse("18h36m56s +38d47m01s")

# Transform to galactic
galactic = vega.to_galactic()
print(f"l = {galactic.l.degrees:.2f}°")
print(f"b = {galactic.b.degrees:.2f}°")

# Create from degrees
m31 = ICRSCoord.from_degrees(ra=10.684, dec=41.269)