spiral galaxy
5
5.9
- noun
- /ˈspaɪrəl ˈɡæləksi/
- Specialized
:
galaxia espiral
- The data showed that fully half of them are forming stars about as vigorously as spiral galaxies do.
- merger of spiral galaxies
- disk of the spiral galaxy
- spiral galaxy rotation
Examples
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Clues to the Milky Way's general appearance were first obtained by analogy with the shapes of nearby spiral galaxies.
Academic text (1995) -
Some faint dwarf spiral galaxies, for example, are six to seven times smaller than the Milky Way.
Academic text (1993) -
But for spiral galaxies, that transition is happening much more slowly.
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Surprisingly, the ring appears to be standing almost perpendicular to the relatively flat disk of the spiral galaxy.
Academic text (1992) -
We still don't know for sure whether the number of spiral galaxies has decreased with time.
Academic text (1995) -
Known as the Leo Triplet, this trio of spiral galaxies fits easily in a 1 field of view.
Academic text (2005) -
If a companion is dropped through the disc of a spiral galaxy, it can leave ripples (see photo, left).
Academic text (1995) -
Some theorists have long maintained that the merger of two spiral galaxies could form an elliptical galaxy.
Academic text (1995) -
If large quantities of dark matter surround most spiral galaxies, astronomers would expect to see many examples of distorted spiral arms.
Academic text (1992) -
The beautiful M101 is a massive spiral galaxy more than twice the size of our Milky Way.
Synonyms
525
4.1
A large system of stars, gas, and dust held together by gravity
1
8.1
A large group of stars in a flat spiral shape with arms of young stars around an older centre
Surface Forms
Morphology
The meaning is directly compositional: 'spiral' denotes a winding shape and 'galaxy' denotes a star system, so a B1 learner who knows both words can infer it is a galaxy with a spiral (winding) structure. This noun–noun combination follows a common, cross-linguistic descriptive pattern, making the expression readily understandable from its parts.
Etymology
The noun spiral galaxy names a galaxy that looks like a bright center with long, curved arms that spread out in a turning pattern, like a spinning pinwheel. The word spiral shows the turning shape and galaxy means 'a big group of stars', so the name helps you picture this kind of galaxy.