astronomy

Messier 83

Messier 83 is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Messier 83 rather than just read about it. In short: Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a barred spiral galaxy approximately 15 million light-years away from Earth in the constellation borders of Hydra and Centaurus. Nicolas-Louis de Lacaille discovered M83 on 17 February 1752 at the Cape of Good Hope.

Key takeaways

Messier 83 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Messier 83 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Messier 83 from memory before moving on to harder problems.

Reference excerpt

Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a barred spiral galaxy approximately 15 million light-years away from Earth in the constellation borders of Hydra and Centaurus. Nicolas-Louis de Lacaille discovered M83 on 17 February 1752 at the Cape of Good Hope. Charles Messier added it to his catalogue of nebulous objects (now known as the Messier Catalogue) in March 1781. It is one of the closest and brightest barred spiral galaxies in the sky, and is visible with binoculars. It has an isophotal diameter at about 36.24 kiloparsecs (118,000 light-years). Its nickname of the Southern Pinwheel derives from its resemblance to the Pinwheel Galaxy (M101).

Characteristics

M83 is a massive, grand design spiral galaxy. Its morphological classification in the De Vaucouleurs system is SAB(s)c, where the 'SAB' denotes a weak-barred spiral, '(s)' indicates a pure spiral structure with no ring, and 'c' means the spiral arms are loosely wound. The peculiar dwarf galaxy NGC 5253 lies near M83, and the two likely interacted within the last billion years resulting in starburst activity in their central regions. The star formation rate in M83 is higher along the leading edge of the spiral arms, as predicted by density wave theory. NASA's Galaxy Evolution Explorer project on 16 April 2008 reported finding large numbers of new stars in the outer reaches of the galaxy—20 kpc from the center. It had been thought that these areas lacked the materials necessary for star formation. In April 2025 it was published that first clues were found for the possible existence of a supermassive black hole at the center of M83.

Supernovae Six supernovae have been observed in M83:

SN 1923A (type unknown, mag. 14) was discovered by Carl Otto Lampland on 5 May 1923. SN 1945B (type unknown, mag. 14.2) was discovered by William Liller on 13 July 1945. SN 1950B (type unknown, mag. 14.5) was discovered by Guillermo Haro on 15 March 1950. SN 1957D (type unknown, mag. 15) was discovered by Howard S. Gates on 28 December 1957. SN 1968L (Type II-P, mag. 11.9) was discovered by John C. Bennett on 17 July 1968. SN 1983N (Type Ia, mag. 11.9) was discovered by Robert Evans from Australia on 3 July 1983. On 6 July, it was observed with the Very Large Array and became the first Type I supernova to have a radio emission detected. The supernova reached peak optical brightness on 17 July, achieving an apparent visual magnitude of 11.54. Although identified as Type I, the spectrum was considered peculiar. A year after the explosion, about 0.3 M☉ of iron was discovered in the ejecta. This was the first time that such a large amount of iron was unambiguously detected from a supernova explosion. SN 1983N became the modern prototype of a hydrogen deficient Type Ib supernova, with the progenitor being inferred as a Wolf–Rayet star.

Environment M83 is at the center of one of two subgroups within the Centaurus A/M83 Group, a nearby galaxy group. Centaurus A is at the center of the other subgroup. These are sometimes identified as one group, and sometimes as two. However, the galaxies around Centaurus A and the galaxies around M83 are physically close to each other, and both subgroups appear not to be moving relative to each other.

See also List of Messier objects M83 (band), the band named after the galaxy

References

External links

Messier 83 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images ESO Photo Release eso0136, An Infrared Portrait of the Barred Spiral Galaxy Messier 83 M83, SEDS Messier pages Spiral Galaxy Messier 83 at the astro-photography site of Takayuki Yoshida M83 The Southern Pinwheel X-rays Discovered From Young Supernova Remnant Archived 17 June 2019 at the Wayback Machine (SN 1957D) Bauer, Amanda; Haese, Paul. "M83 – Southern Pinwheel Galaxy". Deep Sky Videos. Brady Haran. Messier 83 (Southern Pinwheel Galaxy) at Constellation Guide

Illustrations

Worked examples

Example 1 — a first encounter with Messier 83

Start with the simplest possible case. Write down what Messier 83 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Messier 83 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Messier 83 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Messier 83

In research: Messier 83 appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Messier 83 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Messier 83 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1752, Barred spiral galaxies, Centaurus A/M83 Group, so understanding it makes those chapters shorter.
In everyday life: Look for Messier 83 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Messier 83 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Messier 83 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Messier 83 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Messier 83 in simple terms?

Why does Messier 83 matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Messier 83?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Messier 83.