astronomy

NGC 6902

NGC 6902 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 NGC 6902 rather than just read about it. In short: NGC 6902 is an unbarred spiral galaxy located in the southern constellation of Sagittarius at an approximate distance of 124 million light-years (38.0 Mpc). NGC 6902 was discovered on September 2, 1836 by English astronomer John Herschel.

Key takeaways

NGC 6902 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NGC 6902 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 6902 from memory before moving on to harder problems.

Reference excerpt

NGC 6902 is an unbarred spiral galaxy located in the southern constellation of Sagittarius at an approximate distance of 124 million light-years (38.0 Mpc). NGC 6902 was discovered on September 2, 1836 by English astronomer John Herschel. In his New General Catalogue, Danish astronomer J. L. E. Dreyer described it as faint, considerably small, round, brighter middle. It is a member of the small NGC 6092 group of galaxies; the LGG 434 group. The morphological classification of NGC 6902 is SA(r)b, indicating an unbarred spiral galaxy (SA) with an inner ring (r) and somewhat tightly wound arms (b). As the two arms extend outward, they transition into a complex system of filamentary arms. The galaxy has an angular size of 3.55′ × 2.69′ in the optical band. The galactic plane is inclined at an angle of 38±5° to the line of sight from the Earth. NGC 6902 has a high abundance of neutral hydrogen; about three times greater than a typical galaxy of this class. The ring structure is undergoing extensive star formation. Although classed as unbarred, there is a small bar of stars inside the ring.

Supernova One supernova has been observed in NGC 6902:

SN 2024uwq (Type Ic-BL, mag. 17.38) was discovered by ATLAS on 7 September 2024.

Gallery

See also List of NGC objects (6001–7000)

References

External links "Results for object NGC 6902 (NGC 6902)". NASA/IPAC Extragalactic Database. California Institute of Technology. Retrieved 2020-12-12. Media related to NGC 6902 at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with NGC 6902

Start with the simplest possible case. Write down what NGC 6902 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 NGC 6902 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 NGC 6902 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 NGC 6902

In research: NGC 6902 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 NGC 6902 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: NGC 6902 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1836, Discoveries by John Herschel, ESO objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 6902 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 NGC 6902 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 6902 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 NGC 6902 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 6902 in simple terms?

Why does NGC 6902 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 NGC 6902?

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 NGC 6902.