Hour (Sidereal) to Second Converter
Unit Converter
Instant · Precise · Universal
28 units available
6 categories total
How to Convert Hour (Sidereal) to Second
To convert sidereal hours to solar seconds: multiply by 3,590.17. To solar hours: multiply by 0.99727.
1 sidereal hour = 3,590.17 solar seconds ≈ 59 min 50.17 s in solar time. 24 sidereal hours = 1 sidereal day.
For example, 1 Hour (Sidereal) (h (Sid)) = 3590.1704 Second (s).
Hour (Sidereal) to Second — Common Values
| Hour (Sidereal) (h (Sid)) | Second (s) |
|---|---|
| 0.1 | 359.01704 |
| 0.5 | 1795.0852 |
| 1 | 3590.1704 |
| 2 | 7180.3408 |
| 5 | 17950.852 |
| 10 | 35901.704 |
| 25 | 89754.26 |
| 50 | 179508.52 |
| 100 | 359017.04 |
| 500 | 1795085.2 |
| 1000 | 3590170.4 |
About Hour (Sidereal) (h (Sid))
Definition
The sidereal hour is 1/24 of a sidereal day — approximately 3,590.17 seconds (59 minutes and 50.17 seconds in solar time).
Mathematical Relationship
1 sidereal hour = 3,590.17 solar seconds ≈ 59 min 50.17 s in solar time. 24 sidereal hours = 1 sidereal day.
Conversion Formula
To convert sidereal hours to solar seconds: multiply by 3,590.17. To solar hours: multiply by 0.99727.
Practical Applications
Right ascension in celestial coordinates is measured in hours (0–24 h of sidereal time), directly using sidereal hours.
Interesting Facts
Right ascension is measured in hours: 1 h of RA = 15° of sky. The entire sky is 24 sidereal hours in rotation.
Common Mistakes
Treating sidereal hours as exactly 60 solar minutes. The ~10-second difference matters for precision tracking.
Educational Tips
If you use a star-tracking telescope, it rotates once per sidereal day (23h 56m). Each sidereal hour, it covers 15° of sky.
About Second (s)
Definition
The second is the SI base unit of time, defined by the fixed value of the cesium-133 hyperfine transition frequency: exactly 9,192,631,770 cycles.
Mathematical Relationship
1 s = 1,000 ms = 10⁶ µs = 10⁹ ns. There are 60 seconds in a minute and 86,400 in a day.
Conversion Formula
To convert seconds to minutes: divide by 60. To convert to hours: divide by 3,600. To milliseconds: multiply by 1,000.
Practical Applications
All timekeeping — clocks, timers, stopwatches, cooking, traffic lights, music tempo (BPM), and heartbeat monitoring.
Interesting Facts
Cesium atomic clocks are accurate to about 1 second in 300 million years. The 2019 SI redefinition preserved the second's cesium-based definition.
Common Mistakes
Using 'sec' instead of 's' in scientific writing. Also, assuming all seconds are exactly equal — leap seconds exist to correct for Earth's slowing rotation.
Educational Tips
A heartbeat lasts about 0.8 seconds. Counting 'one Mississippi' is a classic way to estimate one second.