astronomy

PKS 2255−282

PKS 2255−282 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 2255−282 rather than just read about it. In short: PKS 2255−282 is a blazar located in the constellation of Piscis Austrinus. This is a low-polarized quasar at the redshift of 0.926, first discovered in 1975 by astronomers via a spectroscopic observation.

Key takeaways

PKS 2255−282 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 2255−282 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 2255−282 from memory before moving on to harder problems.

Reference excerpt

PKS 2255−282 is a blazar located in the constellation of Piscis Austrinus. This is a low-polarized quasar at the redshift of 0.926, first discovered in 1975 by astronomers via a spectroscopic observation. The radio spectrum of this source appears as flat, making it as a flat-spectrum quasar but also a Gigahertz Peaked Spectrum source (GPS) with turnover frequency between 22 and 37 GHz.

Description PKS 2255−282 is found variable on the electromagnetic spectrum. It is a source of gamma ray activity. Furthermore, it underwent a powerful millimeter wave outburst detected in 1997. During April 1997, its 90 GHz flux density exceeded 8 Jansky (Jy), which was twice the value compared to the prior observation 11 months prior to the outburst. At the end June 1997, the 90 GHz flux reached 10.1 Jy making PKS 2255−282 one of the fewer sources with high detections above 10 Jy. In December 1997, PKS 2255−282 showed a gamma ray flare which lasted for a period of 2 weeks. During the observations, it remained in a bright state with a total measured flux of (1.6 ± 0.3) × 10−6 cm−2 s−1 and a peak flux of (4.8 ± 1.1) × 10−6 cm−2 s−1, making this value higher by factor of 20, than the upper limits of its quiescent state. A gamma ray outburst was observed by the Energetic Gamma Ray Experiment Telescope mounted abroad the Compton Gamma Ray Observatory in January 1998. In September 2012, a near-infrared ray was shown to be brightening. The radio structure in PKS 2255−282 is complex. A 5 GHz radio image of the object made via Very Long Baseline Array, shows a strong bright core component marginally resolved at 2.8 Jy and a short jet extending southwest by 5 mas. However, when shown at higher frequencies, the jet is completely omitted from radio imaging with the core only present at 4.2 and 2.7 Jy. This core is estimated to have a size of 0.2 mas with extended emission in both south and east directions. A quasi-periodic oscillation was detected in PKS 2255−282 in October 2024 with a period of 97 days. This is possibly explained by a binary black hole system which a model shows a secondary black hole orbiting round the primary black hole before passing through an accretion disk. Quasi-periodic signals have also been detected in this object with three high states showed during 2009–2013, 2017-2021 and in 2023.

References

External links PKS 2255−282 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PKS 2255−282

Start with the simplest possible case. Write down what PKS 2255−282 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 2255−282 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 2255−282 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 2255−282

In research: PKS 2255−282 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 2255−282 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 2255−282 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 1975, Blazars, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 2255−282 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 2255−282 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 2255−282 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 2255−282 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 2255−282 in simple terms?

Why does PKS 2255−282 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 2255−282?

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 2255−282.