astronomy

NGC 7160

NGC 7160 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 7160 rather than just read about it. In short: NGC 7160 is an open cluster in the constellation Cepheus. It was discovered by William Herschel on November 9, 1789.

Key takeaways

NGC 7160 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 7160 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 7160 from memory before moving on to harder problems.

Reference excerpt

NGC 7160 is an open cluster in the constellation Cepheus. It was discovered by William Herschel on November 9, 1789. The cluster was also observed by John Herschel on October 7, 1829. It is a poor cluster and with little central concentration, with Trumpler class II3p. It is part of the stellar association Cepheus OB2, located one degree south-southwest of VV Cephei.

Description NGC 7160 is a young cluster, whose age is estimated to be between 10 and 19 million years. The cluster presents no extended infrared emission when observed by Spitzer Space Telescope and Herschel Space Telescope which suggests that the molecular cloud in which it was formed has been removed. NGC 7160 lies within the Cepheus Bubble, an expanding dusty shell with a diameter of about 10 degrees, which corresponds to 120 pc (390 ly) at the distance of NGC 7160. It is bordered by HII regions like IC 1396, in which is located the open cluster Trumpler 37. The total mass of molecular gas in the Cepheus Bubble is estimated to be 105 M☉ based on CO emission mapping. The bubble is believed to have been formed by the stellar wind and photoionisation from OB stars that have exploded as supernovae. Mu Cephei, Nu Cephei, and NGC 7160 may have been companions of those stars. It has been suggested that Lambda Cephei and 68 Cygni are runaway stars from that area.

The core radius of the cluster is 0.73 parsec (2.4 light years), while the tidal radius is 5.7 parsecs (18.5 light years) and represents the average outer limit of NGC 7160, beyond which a star is unlikely to remain gravitationally bound to the cluster core. 16 stars, probable members of the cluster, are located within the central part of the cluster, and 71 probable members are located within the angular radius of the cluster. Among the members is EM Cephei (mag 7.03), a variable star whose spectrum switches between B and Be star states. It is suggested it is a Be star with a variable circumstellar disk with mass losses (6±3)×10−11 M☉ per year. One low mass member, with spectral type K4.5 is accreting, suggesting the presence of a protoplanetary disk. It is characterised by very low far-IR flux with a high accretion rate.

Illustrations

Worked examples

Example 1 — a first encounter with NGC 7160

Start with the simplest possible case. Write down what NGC 7160 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 7160 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 7160 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 7160

In research: NGC 7160 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 7160 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 7160 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1789, Cepheus (constellation), Discoveries by William Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 7160 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 7160 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 7160 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 7160 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 7160 in simple terms?

NGC 7160 is an open cluster in the constellation Cepheus. It was discovered by William Herschel on November 9, 1789.

Why does NGC 7160 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 7160?

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 7160.