astronomy

WR 135

WR 135 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 WR 135 rather than just read about it. In short: WR 135 is a variable Wolf–Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus, surrounded by a faint bubble nebula blown by the intense radiation and fast wind from the star. It is just over four times the radius of the sun, but due to a temperature of 63,000 K it is 250,000 times as luminous as the sun.

Key takeaways

WR 135 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect WR 135 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of WR 135 from memory before moving on to harder problems.

Reference excerpt

WR 135 is a variable Wolf–Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus, surrounded by a faint bubble nebula blown by the intense radiation and fast wind from the star. It is just over four times the radius of the sun, but due to a temperature of 63,000 K it is 250,000 times as luminous as the sun. WR 135, together with WR 134 and WR 137, was one of three stars in Cygnus observed in 1867 to have unusual spectra consisting of intense emission lines rather than the more normal continuum and absorption lines. These were the first members of the class of stars that came to be called Wolf–Rayet stars (WR stars) after Charles Wolf and Georges Rayet who discovered their unusual appearance. It is a member of the carbon sequence of WR stars, indicated by the lack of nitrogen lines and the strength of carbon emission. WR 135 has a spectrum with CIII emission slightly stronger than CIV, leading to the assignment of a WC8 spectral type. The spectrum also shows strong HeI emission and weaker lines of HeII and CII. WR 135 is less than a degree away from WR 134 and the two are believed to lie at approximately the same distance from Earth within the Cygnus OB3 association. Both stars lie within a shell of hydrogen thought to have been swept up from the interstellar medium when one or both stars were on the main sequence. The shell is over forty parsecs wide and contains about 1,830 M☉ of hydrogen. It is unclear which of the two stars is primarily responsible for creating the shell. WR 135 has two close companions. HD 228235 is an 11th magnitude star 53" away and there is also a 12th magnitude star 41" away.

References

External links Wolf-Rayet shells showing a spectrum of WR 135 WR134 Ring Nebula with WR 135 visible in the top left corner

Worked examples

Example 1 — a first encounter with WR 135

Start with the simplest possible case. Write down what WR 135 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 WR 135 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 WR 135 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 WR 135

In research: WR 135 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 WR 135 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: WR 135 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cygnus (constellation), Durchmusterung objects, Henry Draper Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for WR 135 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 WR 135 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what WR 135 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 WR 135 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is WR 135 in simple terms?

Why does WR 135 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 WR 135?

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 WR 135.