astronomy

Sh 2-297

Sh 2-297 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 Sh 2-297 rather than just read about it. In short: Sh 2-297 (also known as Sharpless 297) is an emission nebula in the constellation Canis Major. The region was catalogued in 1959 in the extended seconded edition of the Sharpless catalogue.

Key takeaways

Sh 2-297 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sh 2-297 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sh 2-297 from memory before moving on to harder problems.

Reference excerpt

Sh 2-297 (also known as Sharpless 297) is an emission nebula in the constellation Canis Major. The region was catalogued in 1959 in the extended seconded edition of the Sharpless catalogue. This area is part of the Canis Major OB1 Association, and is a very active area of new star formation. Studies in 1988 found that the bright star illuminating the nebula was 8th magnitude HD 53623 / HIP 34178 with spectral class B1II/III. Later in 2004 it was shown that there was embedded a cold but massive Young Stellar Object or YSO within Sh 2-297 near the edge of one of the dark rifts. This object has been observed in the far-infrared, but it is so deeply embedded in an interstellar cloud that it is undetectable in shorter wavelength observations such as the Two Micron All Sky Survey (2MASS), leading it to be originally named "Unidentified young stellar object 1" or UYSO-1. It was further revealed that this unseen stellar source produces a carbon monoxide (CO) bipolar outflow with a total mass of 5.4 M☉ solar masses, while the surrounding extended envelope weighs 30 M☉–40 M☉. Some 96 other YSOs have been discovered to be part of Sh-297, having a mean age of one million years and range in masses between 0.3 M☉ and 2.0 M☉. Many variable stars are also assigned with this nebula complex, including the three brightest: MW Ori, TT Ori and V559 Ori. Distance is estimated between 1.0 and 1.4 kpc. (3,300–4,600 ly.), averaging 1.2 kpc. or 3,900 ly.

History of observation This region was catalogued as part of the major clustering of reflection nebula as CMa R1 by van den Bergh in 1966. Reflection nebulas were identified on blue plates of the Palomar Sky Survey, with positive confirmation made by checking nebulosity on the red plates. It was again later catalogued as LBN 1037 or LBN 225.27-02.42

See also IC 2177 Southern celestial hemisphere

References

Illustrations

Worked examples

Example 1 — a first encounter with Sh 2-297

Start with the simplest possible case. Write down what Sh 2-297 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 Sh 2-297 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 Sh 2-297 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 Sh 2-297

In research: Sh 2-297 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 Sh 2-297 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: Sh 2-297 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Canis Major, RCW Catalogue, Reflection nebulae, so understanding it makes those chapters shorter.
In everyday life: Look for Sh 2-297 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Sh 2-297” →

Affiliate

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

How to study Sh 2-297 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sh 2-297 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 Sh 2-297 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sh 2-297 in simple terms?

Sh 2-297 (also known as Sharpless 297) is an emission nebula in the constellation Canis Major. The region was catalogued in 1959 in the extended seconded edition of the Sharpless catalogue.

Why does Sh 2-297 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 Sh 2-297?

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 Sh 2-297.