Reflection nebula
The Iris Nebula
Also NGC 7023 · Caldwell 4
A blue reflection nebula, a dust cloud lit like a flower by the young star at its centre.
Measured
- Distance
- about 1,160 light-years (published estimates 1,120–1,300)
- Size
- about 6 light-years across (approximate)
- Constellation
- Cepheus
- Position (J2000)
- RA 21h 01m 36s, Dec +68.17°
How far, from the Sun
About 1,160 light-years. To cross it:
- Light1,160 years
- Voyager 1's speed20.6 million years
- Driving at 100 km/h12.5 billion years
Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.
Facts
- Its blue colour is starlight scattered by dust, a similar effect to the one that makes Earth's sky blue.
How it was found
- William Herschel discovered it in 1794.
Where this comes from
- Gaia DR3 parallax of its star HD 200775, 2.8175 ± 0.0374 mas (Gaia Collaboration 2023, A&A 674, A1)
Every catalogue Ouranos draws is credited on the credits page.