astronomy

NGC 3987

NGC 3987 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 3987 rather than just read about it. In short: NGC 3987 is a spiral galaxy in the constellation of Leo. Its velocity with respect to the cosmic microwave background is 4,810±10 km/s, which corresponds to a Hubble distance of 231.4 ± 16.2 Mly (70.94 ± 4.98 Mpc).

Key takeaways

NGC 3987 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 3987 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 3987 from memory before moving on to harder problems.

Reference excerpt

NGC 3987 is a spiral galaxy in the constellation of Leo. Its velocity with respect to the cosmic microwave background is 4,810±10 km/s, which corresponds to a Hubble distance of 231.4 ± 16.2 Mly (70.94 ± 4.98 Mpc). However, 23 non-redshift measurements give a closer distance of 196.49 ± 4.62 Mly (60.243 ± 1.415 Mpc). It was discovered by German-British astronomer William Herschel on 6 April 1785. NGC 3987 has an active galactic nucleus, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. In addition, it is a LINER galaxy, i.e. a galaxy whose nucleus has an emission spectrum characterized by broad lines of weakly ionized atoms.

Holm 308 and NGC 3987 group NGC 3987, NGC 3989, NGC 3993, and NGC 3997 are listed together as Holm 308 in Erik Holmberg's A Study of Double and Multiple Galaxies Together with Inquiries into some General Metagalactic Problems, published in 1937. However, according to A. M. Garcia, NGC 3987 is the largest galaxy in a group that bears its name. The NGC 3987 group (also known as LGG 261) is thought to have at least five galaxies, including NGC 4000, NGC 4005, NGC 4018, and NGC 4022.

Supernovae Two supernovae have been observed in NGC 3987:

SN 2001V (Type Ia, mag. 16) was discovered by P. Berlind on 19 February 2001. Later analysis concluded that this supernova was overluminous, and its spectral features indicate it might be a SN 1999aa-like object. SN 2025msx (Type Ic-BL, mag. 18.914) was discovered by ATLAS on 1 June 2025.

See also List of NGC objects (3001–4000)

References

External links Media related to NGC 3987 at Wikimedia Commons NGC 3987 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

Illustrations

Worked examples

Example 1 — a first encounter with NGC 3987

Start with the simplest possible case. Write down what NGC 3987 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 3987 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 3987 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 3987

In research: NGC 3987 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 3987 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 3987 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1785, Discoveries by William Herschel, IRAS catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 3987 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 3987 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 3987 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 3987 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 3987 in simple terms?

Why does NGC 3987 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 3987?

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 3987.