Free Star Map Tools
Four utilities for picking the right night sky.
Free to use, no signup, no email required. Each tool runs on the same astronomical engine as our paid star maps: the HYG v4.2 stellar catalog (8,921 stars), the 88 IAU constellations, and the IAU 2006 sidereal time algorithm.
Birthday Constellation Finder
What constellation was overhead the night you were born?
Enter your birthday and get your zodiac sign, the constellation visible overhead at midnight, and one named star inside that constellation with its IAU-recorded magnitude. Calculated from the HYG v4.2 catalog.
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Anniversary Nights Counter
How many nights have you spent under the same sky together?
Enter the date your relationship started. Get the exact day count, full moons shared, meteor showers witnessed, and Earth rotations spent side by side. Useful for proposal speeches and anniversary captions.
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Star Magnitude & Visibility Checker
Is this star visible to the naked eye from a dark site?
Look up any of the 8,921 stars in the HYG v4.2 catalog and get its apparent magnitude, its naked-eye visibility threshold, and the constellation it belongs to. Useful for amateur observers and curious gift-givers.
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Best Date Suggester
Which date should you commemorate with a star map?
Three quick questions about the relationship or milestone, and the tool returns the single most meaningful date to anchor a star map gift — birthday, first date, wedding night, or a custom anchor.
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Want a personalized star map next?
The tools are free utilities. The full configurator turns any date, time, and place into a high-resolution print or instant PDF showing the exact sky overhead — same engine, same catalog, archival paper and 300 DPI output.
Open the configurator