astronomy

PKS 0428+205

PKS 0428+205 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 PKS 0428+205 rather than just read about it. In short: PKS 0428+205 known as OF 247, is a radio galaxy located in the constellation of Taurus. The redshift of the galaxy is (z) 0.220 and it was first discovered as an extragalatic compact source in October 1971 by astronomers.

Key takeaways

PKS 0428+205 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PKS 0428+205 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 0428+205 from memory before moving on to harder problems.

Reference excerpt

PKS 0428+205 known as OF 247, is a radio galaxy located in the constellation of Taurus. The redshift of the galaxy is (z) 0.220 and it was first discovered as an extragalatic compact source in October 1971 by astronomers. It is classified as a compact steep spectrum (CSS) object.

Description PKS 0428+205 displays a gigahertz-peaked radio spectrum at various frequencies. Its source is classified as compact, with radio emission separating into two individual components based on radio imaging made by the Very Large Array (VLA). Another component described as both faint and extended is located 30 milliarcseconds away in the position angle of -30° and has a flux density of 120 mJy. The radio core of PKS 0428+205 is described as elongated along the position angle of -35° with some evidence of a lower surface brightness extension extending towards the northwest. Observations with Very Long Baseline Interferometry (VLBI) at 5 GHz frequencies found there is an undetected northern radio lobe and southern radio lobe that is mainly dominated by a hotspot feature located at a distance of 175 parsecs from the core. An arc of emission can be seen extending in an eastern direction from the northern hotspot. The radiative age of the source is estimated to be 1.2 × 103 years. The host galaxy of PKS 0428+205 is a large normal elliptical galaxy, based on its absolute magnitude and surface brightness profiles not displaying the same characteristics like brightest cluster galaxies. Imaging made with Hubble Space Telescope (HST) described it having a reddened nucleus and is surrounded by a halo mainly extending in the directions of both south and east. There are also fainter objects located within the space of 10 arcseconds A study published in 2013 suggested PKS 0428+205 might be a young radio galaxy in the midst of an early evolution stage.

References

External links PKS 0428+205 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PKS 0428+205

Start with the simplest possible case. Write down what PKS 0428+205 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 PKS 0428+205 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 PKS 0428+205 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 PKS 0428+205

In research: PKS 0428+205 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 PKS 0428+205 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: PKS 0428+205 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 1971, Elliptical galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 0428+205 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 PKS 0428+205 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 0428+205 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 PKS 0428+205 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 0428+205 in simple terms?

Why does PKS 0428+205 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 PKS 0428+205?

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 PKS 0428+205.