astronomy

Messier 63

Messier 63 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 63 rather than just read about it. In short: Messier 63 or M63, also known as NGC 5055 or the Sunflower Galaxy, is a spiral galaxy in the northern constellation of Canes Venatici. M63 was first discovered by the French astronomer Pierre Méchain, then later verified by his colleague Charles Messier on 14 June 1779.

Key takeaways

Messier 63 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 63 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Messier 63 from memory before moving on to harder problems.

Reference excerpt

Messier 63 or M63, also known as NGC 5055 or the Sunflower Galaxy, is a spiral galaxy in the northern constellation of Canes Venatici. M63 was first discovered by the French astronomer Pierre Méchain, then later verified by his colleague Charles Messier on 14 June 1779. The galaxy became listed as object 63 in the Messier Catalogue. In the mid-19th century, Anglo-Irish astronomer Lord Rosse identified spiral structures within the galaxy, making this one of the first galaxies in which such structure was identified. The shape or morphology of this galaxy has a classification of SAbc, indicating a spiral form with no central bar feature (SA) and moderate to loosely wound arms (bc). There is a general lack of large-scale continuous spiral structure in visible light, so it is considered a flocculent galaxy. However, when observed in the near infrared, a symmetric, two-arm structure is seen. Each arm wraps 150° around the galaxy and extends out to 13,000 light-years (4,000 parsecs) from the nucleus. M63 is a weakly active galaxy with a LINER nucleus – short for 'low-ionization nuclear emission-line region'. This displays as an unresolved source at the galactic nucleus that is cloaked in a diffuse emission. The latter is extended along a position angle of 110° relative to the north celestial pole, and both soft X-rays and hydrogen (H-alpha) emission can be observed coming from along nearly the same direction. The existence of a supermassive black hole (SMBH) at the nucleus is uncertain; if it does exist, then the mass is estimated as (8.5±1.9)×108 M☉, or around 850 million times the mass of the Sun. Radio observations at the 21-cm hydrogen line show the gaseous disk of M63 extends outward to a radius of 130,000 light-years (40 kiloparsecs), well past the bright optical disk. This gas shows a symmetrical form that is warped in a pronounced manner, starting at a radius of 33,000 light-years (10 kiloparsecs). The form suggests a dark matter halo that is offset with respect to the inner region. The reason for the warp is unclear, but the position angle points toward the smaller companion galaxy, UGC 8313. The distance to M63, based upon the luminosity-distance measurement is 29,300,000 light-years (8.99 megaparsecs). The radial velocity relative to the Local Group yields an estimate of 15,200,000 light-years (4.65 megaparsecs). Estimates based on the Tully–Fisher relation range over 16,000,000–34,000,000 light-years (5.0–10.3 megaparsecs). The tip of the red-giant branch technique gives a distance of 28,930,000 ± 950,000 light-years (8.87 ± 0.29 megaparsecs). M63 is part of the M51 Group, a group of galaxies that also includes M51 (the 'Whirlpool Galaxy').

Supernova One supernova has been observed in M63: SN 1971I (Type Ia, mag. 11.8) was discovered by Glenn Jolly on 24 May 1971, and was discovered independently by Roger Clark on 29 May 1971. It reached peak light around 26 May. While the spectrum was consistent with a supernova of Type I, the spectroscopic behavior appeared anomalous.

Gallery

Illustrations

Worked examples

Example 1 — a first encounter with Messier 63

Start with the simplest possible case. Write down what Messier 63 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 63 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 63 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 63

In research: Messier 63 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 63 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 63 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1779, Canes Venatici, Discoveries by Pierre Méchain, so understanding it makes those chapters shorter.
In everyday life: Look for Messier 63 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 63 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Messier 63 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 63 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Messier 63 in simple terms?

Why does Messier 63 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 63?

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 63.