astronomy

S5 0212+73

S5 0212+73 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 S5 0212+73 rather than just read about it. In short: S5 0212+73 also known as QSO B0212+735, is a high redshift radio-loud blazar located at (z) 2.346. It lies in the constellation of Cassiopeia, 10.5 billion light-years away from Earth and was one of the six sources discovered in 1981 by astronomers from the Bonn-NRAO 5 GHz survey.

Key takeaways

S5 0212+73 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect S5 0212+73 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of S5 0212+73 from memory before moving on to harder problems.

Reference excerpt

S5 0212+73 also known as QSO B0212+735, is a high redshift radio-loud blazar located at (z) 2.346. It lies in the constellation of Cassiopeia, 10.5 billion light-years away from Earth and was one of the six sources discovered in 1981 by astronomers from the Bonn-NRAO 5 GHz survey. The radio spectrum of the object is flat, thus classifying it a flat-spectrum radio quasar. It has also been referred to as a BL Lacertae object in literature.

Description Variable on the electromagnetic spectrum, S5 0212+73 is constantly active. It displayed a gamma-ray flare on June 26, 2024, where its average gamma-ray flux reached daily levels of 1.1 ± 0.2 × 10−6 photons cm−2 s-1, about a factor of 35 upon detection by Fermi Gamma-ray Space Telescope. Subsequently, the object would later display a slight decrease in gamma-ray flux on July 1, 2024, where its levels reached (+1.59, -1.48) × 10−12 erg cm−2 s−1. The optical to ultraviolet peak of S5 0212+73 is considered narrowly defined because of increasing flux observed in its B-filter. This is mainly attributed to contamination of its continuum flux by a Lyman-alpha emission line. The object also displays an inverted spectrum detected at 6 and 2.8 centimeters (cm) since 1996 with modulation index increasing to 9.1% at 2.8 cm from 6.5% at 6 cm during long-term monitoring by Effelsburg 100-m Radio telescope. The source of the object is compact. According to radio imaging by Very Long Baseline Interferometry (VLBI), it has a one-sided core-jet structure made up of a radio core, and three jet components, with some weaker radio emission located at 4 milliarcseconds away from the core at a position angle of 100°. First-epoch mapping failed to detect an extended structure, while polarization observations by VLBI found a bright core component located west and a radio jet extending south-east from the core. Additionally, there is a weaker component in the west by 15 milliarcseconds. Very Long Baseline Array (VLBA) mapping has shown the jet in S5 0212+73 is the longest observed, with an extent of 14 milliarcseconds. Two distinctive regions are found by the VLBA, mainly a weak extended jet region and an inner core-jet region. S5 0212+73 displays superluminal motion. A later observation noted the inner jet component is separating from the core at an increasing rate from 1.0 to 1.5 milliarcseconds, with a proper motion of 0.09 ± 0.05 milliarcseconds per year. Both the core and jet show rotation measures, with the former having a negative measurement of -542 ± 55 rad m−2 while the former has a positive measurement of +119 ± 64 rad m−2. The magnetic field of the inner jet in S5 0212+73 is offset. When observed, it has an offset angle of 30° and suggested as roughly parallel to the jet's direction northwest, should a smooth line be drawn through the components. Evidence would show the components located in the inner and outer regions of the object have flux density variations marginally consistent to one another, with no observed epoch changes. Other than that, there is an observed steepening of its spectral index as the distance increases from the jet.

References

External links S5 0212+73 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with S5 0212+73

Start with the simplest possible case. Write down what S5 0212+73 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 S5 0212+73 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 S5 0212+73 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 S5 0212+73

In research: S5 0212+73 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 S5 0212+73 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: S5 0212+73 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 1981, BL Lacertae objects, so understanding it makes those chapters shorter.
In everyday life: Look for S5 0212+73 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 S5 0212+73 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what S5 0212+73 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 S5 0212+73 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is S5 0212+73 in simple terms?

Why does S5 0212+73 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 S5 0212+73?

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 S5 0212+73.