Convert Hour (Sidereal) (h (sidereal)) to Second (Sidereal) (s (sidereal)) instantly.
About these units
Hour (Sidereal) (h (sidereal))
A sidereal hour is 1/24 of a sidereal day, approximately 59 minutes and 50.17 seconds of solar time. Astronomers use sidereal hours to measure right ascension and to coordinate telescope pointing systems. Because stars return to the same apparent position after exactly one sidereal day, sidereal hours offer a stable celestial reference frame. While not used in daily life, sidereal hours are indispensable for precision observation of the universe.
Second (Sidereal) (s (sidereal))
A sidereal second is 1/60 of a sidereal minute, equal to about 0.99727 solar seconds. While the difference seems small, it accumulates noticeably over long observing sessions. Sidereal seconds ensure that telescope mounts and tracking systems remain synchronized with the rotation of the celestial sphere. The distinction between solar and sidereal seconds underscores the complexity of Earth's rotational dynamics—reminding us that even "one second" depends on which cosmic frame of reference we choose.