astronomy

UM 287

UM 287 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 UM 287 rather than just read about it. In short: UM 287 known as PHL 868 and LBQS 0049+0045, is a quasar located in the Cetus constellation. Its redshift is 2.267134 estimating the object to be located 10.9 billion light-years away from Earth.

Key takeaways

UM 287 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect UM 287 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of UM 287 from memory before moving on to harder problems.

Reference excerpt

UM 287 known as PHL 868 and LBQS 0049+0045, is a quasar located in the Cetus constellation. Its redshift is 2.267134 estimating the object to be located 10.9 billion light-years away from Earth.

Observation history UM 287 was first discovered between 1974 and 1976, where it was observed as a part of the Curtis Schmidt-thin prism survey for extragalactic emission-line objects and possible quasars. The name UM comes from the University of Michigan.

Characteristics UM 287 is classified as a radio-quiet quasar. It has a bolometric brightness of around 10 47.3 erg /s (10 40 watts), making it one of the brightest quasars ever observed. Furthermore, UM 287 has a Lyman-alpha blob structure surrounding the object. Some of these Lyman-alpha blobs have line luminosities up to ~ 1044 erg s−1 with their spatial extents exceeding 100 proper kpc. But in this case, the Lyman-alpha blob structure in UM 287 is 1.5 million light-years across making it too big to be contained within the quasar's host galaxy, which is found to be a massive early-type galaxy. Using the 10-meter Keck I telescope in Hawaii, a team of researchers found there is cold hydrogen emitting Lyman-alpha radiation underneath the spotlight of the quasar's intense ultraviolet beam. The nebula is dubbed the Slug Nebula, named after the UCSC’s banana slug mascot. It is believed to play a major role in powering up the quasar which the Lyα emission produces from a large population of compact (< 20 pc), dense (nH & 3 cm−3), cool gas clumps. From a follow-up field observation, a smooth kinematic profile is suggested. This presents a giant, rotating proto-galactic disk for the brightest portion of the filament showing a cold accretion flow around the black hole in UM 287. In addition to the Lyman-alpha blob structure, a new dusty star-forming galaxy was found. The galaxy has a 2 mm continuum with its single emission line consistent with the CO(4–3), sitting at a projected distance of 100 kpc southeast from UM 287. The systemic velocity difference is -360 ± 30 km s-1 with respect to UM 287, suggesting the galaxy is a possible contributor to the powering of the Slug Nebula.

References

Illustrations

Worked examples

Example 1 — a first encounter with UM 287

Start with the simplest possible case. Write down what UM 287 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 UM 287 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 UM 287 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 UM 287

In research: UM 287 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 UM 287 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: UM 287 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cetus (constellation), Lyman-alpha blobs, Principal Galaxies Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for UM 287 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 UM 287 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what UM 287 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 UM 287 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is UM 287 in simple terms?

UM 287 known as PHL 868 and LBQS 0049+0045, is a quasar located in the Cetus constellation. Its redshift is 2.267134 estimating the object to be located 10.9 billion light-years away from Earth.

Why does UM 287 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 UM 287?

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 UM 287.