Translation guide
In Japanese, 'nebula' is most commonly expressed as 星雲 (せいうん), the standard astronomical term. For specific types, 星状星雲 (せいじょうせいうん) is used for planetary nebulae, and 暗黒星雲 (あんこくせいうん) for dark nebulae. In everyday contexts, the loanword ネビュラ is sometimes used, especially in science fiction or fantasy.
nebula (astronomical)
Referring to a cloud of gas and dust in outer space, visible as a fuzzy patch of light.
The standard Japanese word for 'nebula' in astronomy. Used in both scientific and general contexts.
The Orion Nebula is visible to the naked eye.
The Hubble Space Telescope captured beautiful images of nebulae.
Loanword from English, often used in science fiction, fantasy, or casual contexts. Less common in formal astronomy.
In that game, an enemy called Nebula appears.
A specific type of nebula formed from the ejected outer layers of a dying star, often appearing as a glowing ring.
The technical term for 'planetary nebula'. Used in astronomy.
The Ring Nebula is a famous planetary nebula.
A nebula that obscures light from objects behind it, appearing as a dark patch against a brighter background.
The standard term for 'dark nebula' in astronomy.
The Horsehead Nebula is a type of dark nebula.
When talking about nebulae in everyday Japanese, 星雲 is perfectly natural. You don't need to use the English loanword unless you're in a sci-fi or gaming context.
Last night I saw a nebula through my telescope.