21 Oph
21 Oph
21 Oph is a A-type (White) star. It carries the designation 21 Oph.
Located approximately 378.8 light-years from Earth, 21 Oph resides within the broader disk of our Milky Way galaxy.
21 Oph is classified as a spectral class A star (A-type (White)) on the Harvard spectral classification system.
With an apparent magnitude of +5.51, 21 Oph sits near the limit of naked-eye visibility. It can be glimpsed without optical aid under dark skies, but binoculars will make observation much easier. Observers will note its blue-white hue, which corresponds to a B-V color index of +0.055.
Physical Properties
| Spectral Class | Class A — A-type (White) |
| Color Index (B−V) | 0.055 |
Observation
| Apparent Magnitude | +5.51 |
| Absolute Magnitude | 0.18 |
| Distance | 379 ly |
Position
| Right Ascension | 16h 51.42m |
| Declination | 1° 12.96′ |
Frequently Asked Questions
What type of star is 21 Oph?
21 Oph is a Class A — A-type (White) star.
How far is 21 Oph from Earth?
21 Oph is approximately 378.8 light-years from Earth.
Can you see 21 Oph with the naked eye?
With an apparent magnitude of 5.51, 21 Oph is visible to the naked eye.