astronomy

NGC 3982

NGC 3982 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 3982 rather than just read about it. In short: NGC 3982 is an intermediate spiral galaxy approximately 68 million light-years away in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel on April 14, 1789, and misclassified as a planetary nebula.

Key takeaways

NGC 3982 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 3982 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 3982 from memory before moving on to harder problems.

Reference excerpt

NGC 3982 is an intermediate spiral galaxy approximately 68 million light-years away in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel on April 14, 1789, and misclassified as a planetary nebula. NGC 3982 is a part of the M109 Group. At an apparent magnitude of 12.0, NGC 3982 needs a telescope to be viewed. Using small telescopes, the galaxy appears as a very faint, diffuse patch of light, with its central region appearing as a slightly brighter diffuse ball.

General NGC 3982 is a Seyfert 2 galaxy that spans about 30,000 light-years, about one-third of the size of our Milky Way galaxy. The galaxy is receding from us at about 1,109 km/s. The galaxy is a typical spiral galaxy, similar to our Milky Way. It harbors a supermassive black hole at its core and has massive regions of star formation in the bright blue knots in the spiral arms. Supernovae are likely to be found within these regions. NGC 3982 has a high rate of star birth within its arms, which are lined by pink star-forming regions of glowing hydrogen and newborn blue star clusters. Its bright nucleus is home to older populations of stars, which grow more densely packed toward the center. The galaxy also has active star formation in the circumnuclear region, estimated at 0.52 M☉/year. The HST image of NGC 3982 shows a mini-spiral between the circumnuclear star-forming region and the galaxy's nucleus, which could be the channel through which gas is transported to the supermassive black hole from the star-forming region. NGC 3982 is a member of the M109 Group, a group of galaxies located in the constellation Ursa Major that may contain over 50 galaxies. The group was named after the brightest galaxy in the group, the spiral galaxy M109. Astronomers are interested in studying this galaxy as it can help in measuring extragalactic distances. It is helpful because it possesses two tools used to estimate astronomical distances: supernovae and Cepheid variable stars.

Supernovae Two supernovae have been observed in NGC 3982:

SN 1998aq (Type Ia, mag. 14.9) was discovered by British amateur astronomer Mark Armstrong on April 13, 1998. It was discovered when it had an apparent magnitude of 14.9, and had grown considerably brighter by two days after its initial sighting, eventually reaching maximum magnitude of 12.0. SN 2025ajmz (Type IIn, mag. 20.5335) was discovered by the Zwicky Transient Facility on November 28, 2025. It was initially classified as Type IIn, but later analysis suggested that it instead might be a LBV-like eruption or a pre-supernova eruption.

See also List of NGC objects (3001–4000)

References

External links

Spiral Galaxy NGC 3982 @ SEDS NGC objects pages Stetson, Peter B.; Gibson, Brad K. (2001). "The Distance to Supernova 1998aq in NGC 3982". Monthly Notices of the Royal Astronomical Society. 328 (1): L1. arXiv:astro-ph/0110062. Bibcode:2001MNRAS.328L...1S. doi:10.1046/j.1365-8711.2001.05005.x. S2CID 119461606. NGC 3982 at ESA/Hubble Circumnuclear Star Forming Activity in NGC 3982 Archived 2016-03-04 at the Wayback Machine

Illustrations

Worked examples

Example 1 — a first encounter with NGC 3982

Start with the simplest possible case. Write down what NGC 3982 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 3982 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 3982 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 3982

In research: NGC 3982 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 3982 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 3982 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1789, Discoveries by William Herschel, IRAS catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 3982 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study NGC 3982 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 3982 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 3982 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 3982 in simple terms?

Why does NGC 3982 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 3982?

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 3982.