astronomy

PKS 1538+149

PKS 1538+149 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 1538+149 rather than just read about it. In short: PKS 1538+149 also known as 4C 14.60, is a BL Lacertae object located in the constellation of Serpens. The redshift of the object is found to be (z) 0.605 and was discovered through photoelectric observations in February 1975 by astronomers who observed it had a continuous spectra.

Key takeaways

PKS 1538+149 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 1538+149 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 1538+149 from memory before moving on to harder problems.

Reference excerpt

PKS 1538+149 also known as 4C 14.60, is a BL Lacertae object located in the constellation of Serpens. The redshift of the object is found to be (z) 0.605 and was discovered through photoelectric observations in February 1975 by astronomers who observed it had a continuous spectra. The radio spectrum of the source is flat, describing it a flat-spectrum radio quasar (FRSQ).

Description PKS 1538+149 is shown undergoing a decrease in brightness levels by displaying a low visual magnitude of 1.7 as observed by E.R. Craine and K. Johnson. It is noted to be variable too, when it was detected by J.T. Pollock in 1975, who noted the object had an amplitude exceeding more than a magnitude of 2.8 ± 0.20, however it has no evidence of variations in X-ray flux. During the period between April and June 1986, the light curve data, showed it undergoing a decrease of 0.0026 magnitude per day, averaging on the magnitude of 18.54. The object is also classified as a blazar due to its high optical polarization, displaying large variations more than 1 magnitude while the spectral index described as both steep and also variable, remained constant. The radio structure of PKS 1538+149 is described as compact. On arcsecond scales, the source has a size of 6 centimeters with radio emission depicted as being concentrated in its northern region. Observations also showed the source is elongated with radio frequency identification imaging finding the emission further extends northwest by 60 milliarcseconds and by 10 milliarcseconds at 8.4 GHz frequencies. It is found PKS 1538+149 has a jet with jet power of 2.36 × 1045 ergs with an opening angle of 16.1°. The radio core is noted shifting by 0.032 milliarcseconds in frequencies of 8.1-15.3 GHz. Earlier observations, especially using near-infrared H-band found PKS 1538+149 has an unresolved host galaxy. Imaging with Hubble Space Telescope would later reveal the host galaxy is indeed a round elliptical galaxy, surrounded by several other faint galaxies within its vicinity. It has a low surface brightness and V-I color of 2.85. A de Vaucouleurs model also described the host galaxy as large and luminous with a measured magnitude of -25.1 and length of 21 kilometers in size. A central supermassive black hole mass of 7.54 × 104 M☉ was found for the object.

References

External links PKS 1538+149 on NASA/IPAC Database PKS 1538+149 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PKS 1538+149

Start with the simplest possible case. Write down what PKS 1538+149 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 1538+149 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 1538+149 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 1538+149

In research: PKS 1538+149 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 1538+149 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 1538+149 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 4C objects, Active galaxies, Astronomical objects discovered in 1975, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 1538+149 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 1538+149 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 1538+149 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 1538+149 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 1538+149 in simple terms?

Why does PKS 1538+149 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 1538+149?

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 1538+149.