Norma, the Carpenter’s Square, is a small southern constellation in the Milky Way between Lupus and Ara, and it lends its name to an arm of the Galaxy.
At a glance
| stars in the figure | 4 |
|---|---|
| nearest star of the figure | Delta Normae, 122 light-years (37.5 pc) |
| farthest star of the figure | Epsilon Normae, 530 light-years (163 pc) |
| depth | the farthest is 4.3 × farther than the nearest |
Read off the piece’s own catalogue, the same values it draws with.
About Norma
Norma is one of the constellations added by Nicolas-Louis de Lacaille, who originally called it the square and rule, the instruments of the draughtsman and carpenter. It is so small and faint that its original leading stars were later moved into neighbouring constellations, so it has no star called Alpha Normae; its brightest is Gamma² Normae, a yellow giant.
It lies across a dense stretch of the southern Milky Way, between Scorpius, Lupus and Ara, crowded with star clusters and dark lanes of dust. Looking through Norma means looking along the Galaxy’s disc toward its inner regions, and the Norma Arm, one of the inner spiral arms, takes its name from this direction.
Norma is a southern-hemisphere constellation, best seen on winter evenings there. From mid-northern latitudes it barely clears the southern horizon in summer, if at all.
What you see in the piece
With CONSTELLATIONS (N) on, fly away from the HUMAN EYE view (E): the square’s nearest star sits several times closer than its farthest, and the right angle drawn from Earth folds into a scatter of stars at different depths.
Questions
Why is it called Norma?
Lacaille named it after the carpenter’s square and rule, instruments used to draw straight lines and right angles. The name was shortened to Norma, the square.
How far away are the stars of Norma?
The nearest star of the figure is Delta Normae, 122 light-years (37.5 pc); the farthest is Epsilon Normae, 530 light-years (163 pc), so the farthest is 4.3 × farther than the nearest.