chemistry

NGC 1999

NGC 1999 is a chemistry 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 1999 rather than just read about it. In short: NGC 1999, is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. Alternatively, it known as The Cosmic Keyhole.

Key takeaways

NGC 1999 belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NGC 1999 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 1999 from memory before moving on to harder problems.

Reference excerpt

NGC 1999, is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. Alternatively, it known as The Cosmic Keyhole. It is a reflection nebula, and shines from the light of the variable star V380 Orionis. It was previously believed that the black patch was a dense cloud of dust and gas which blocked light that would normally pass through, called a dark nebula. Analysis of this patch by the infrared telescope Herschel (October 9, 2009), which has the capability of penetrating such dense cloud material, resulted in continued black space. This led to the belief that either the cloud material was immensely dense or that an unexplained phenomenon had been detected. With support from ground-based observations done using the submillimeter bolometer cameras on the Atacama Pathfinder Experiment radio telescope (November 29, 2009) and the Mayall (Kitt Peak) and Magellan telescopes (December 4, 2009), it was determined that the patch looks black not because it is an extremely dense pocket of gas, but because it is truly empty. The exact cause of this phenomenon is still being investigated, although it has been hypothesized that narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas, as well as, powerful radiation from a nearby mature star may have helped to create the hole. Researchers believe this discovery should lead to a better understanding of the entire star forming process. It is located 1,500 light-years away from Earth in the constellation Orion. HH 1/2, the first recognized Herbig-Haro Object, is located near NGC 1999.

References

External links Media related to NGC 1999 at Wikimedia Commons Andrew Fazekas (May 12, 2010). "Hole in Space Found by Orbiting Telescope". National Geographic. Archived from the original on May 13, 2010. Retrieved 2018-03-07.

Illustrations

Worked examples

Example 1 — a first encounter with NGC 1999

Start with the simplest possible case. Write down what NGC 1999 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, 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 1999 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 1999 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 1999

In research: NGC 1999 appears in chemistry 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 1999 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 1999 is common in secondary-school and first-year university syllabi. It links to neighbouring topics NGC objects, Orion (constellation), Orion molecular cloud complex, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 1999 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 1999 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 1999 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 1999 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 1999 in simple terms?

NGC 1999, is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. Alternatively, it known as The Cosmic Keyhole.

Why does NGC 1999 matter?

Because it connects several chemistry 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 1999?

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 1999.