Norma

What is Norma?

Constellations· Southern winter · in the Milky Way between Scorpius and Lupus. Lacaille's tribute to the carpenter's set square. Its stars are faint, but it sits in the thick of the Milky Way and is full of clusters — and beyond it hides the Great Attractor that galaxies are streaming toward.

Where Norma is in your sky right now: https://nowsky.org/solar/sky?sel=con:Norma — location and time set automatically, no login.

Stars of the figure

The 2 brightest of the 2 stars used in the figure (1 lines). Lower magnitude means brighter.

Constellation basics

Figures are representative approximations. Source: compiled from NASA and IAU public data.

Frequently asked

When can I see Norma?

Jun–Jul evenings; grazes the horizon from Korea.

How do I find Norma?

west of the Scorpion's tail, southeast of Lupus.

What is the brightest star in Norma?

Gamma2 Normae, magnitude 4.

Where is Norma in the sky right now?

Open the sky view for your location and time and it shows the position in the sky right now.

A name given to one of the Milky Way's arms — the Norma Arm

One of the Milky Way's spiral arms carries the name of Norma. The Norma Arm, an inner arm near the galactic centre, is seen from the Sun tangentially in the direction of this constellation, so its stars and gas pile up along the line of sight in that part of the sky. The arm's existence was confirmed from the velocity distribution of hydrogen gas in radio surveys, and the constellation's name became the arm's.

In the same way the Sagittarius, Scutum–Centaurus and Perseus arms took their names from the constellations where their tangents appear; the Sun sits in the small Orion Arm between them. Norma is a small constellation without a bright star, yet on the map of the galaxy it serves as the label of a major structure, and the unusual number of clusters in this direction is because we are looking through the arm edge-on.

The constellation in depth

Norma is one of the scientific-instrument constellations Lacaille drew in the 1750s, first called the Set Square and Rule, and paired with the neighbouring Circinus. When boundaries were redrawn later, its original alpha and beta stars were handed to Scorpius, leaving the odd situation in which gamma Normae now serves as its brightest star. Gamma-2 Normae, a yellow giant about 130 light-years away, is the brightest at magnitude 4.0.

Lying in the heart of the Milky Way it is rich in open clusters: NGC 6087 contains the Cepheid variable S Normae, and NGC 6067, reminiscent of the Jewel Box, is a fine binocular target. About 200 million light-years beyond it lies the Norma cluster, thought to sit near the centre of the Great Attractor, the mass pulling on tens of thousands of galaxies including our own.

At declinations of −42° to −60°, only its top grazes the southern horizon from Korea around midnight in June and July. From the southern hemisphere, find it on winter evenings in the Milky Way west of the Scorpion's tail, between Lupus and Ara. In the Sky view, set Sydney on a July evening and look beside the sting. Its clusters make it a better target for binoculars than for the naked eye. The constellation lines help, since none of its stars is bright.

Related

Figures are representative approximations. Simulated positions use J2000 mean elements.