Limits RegistryPUBLIC RECORD
Limits RegistryS5-HVS1, an A-type star discovered in 2019 by the Southern Stellar Stream Spectroscopic Survey, is moving at roughly 1,755 km/s — fast enough to escape the Milky Way entirely — and is believed to have been ejected by a close encounter with the supermassive black hole Sagittarius A* around 5 million years ago. It remains the fastest star known with a well-constrained trajectory back to that origin.
The question, scope, and sources behind this Registry record.
S5-HVS1, an A-type star discovered in 2019 by the Southern Stellar Stream Spectroscopic Survey, is moving at roughly 1,755 km/s — fast enough to escape the Milky Way entirely — and is believed to have been ejected by a close encounter with the supermassive black hole Sagittarius A* around 5 million years ago. It remains the fastest star known with a well-constrained trajectory back to that origin.
The greatest speed relative to the Galactic rest frame confirmed for any star that is gravitationally unbound from the Milky Way.
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Current frontiers derived from accepted Claims.
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The frontier as it changed over time.
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1 accepted Claim, with 1 linked evidence records.
Permanent ID limitsregistry.com/limits/LR-FASTEST-HYPERVELOCITY-STAR
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Limits Registry. LR-FASTEST-HYPERVELOCITY-STAR. Fastest hypervelocity star known. 2026.