astronomy

HD 259431

HD 259431 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 HD 259431 rather than just read about it. In short: HD 259431 (MWC 147 or V700 Monocerotis) is a young stellar object in the constellation of Monoceros. Location HD 259431 lies in the northern portion of Monoceros, between Orion and Canis Minor, along with the spectacular Rosette Nebula and NGC 2264 region.

Key takeaways

HD 259431 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HD 259431 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 259431 from memory before moving on to harder problems.

Reference excerpt

HD 259431 (MWC 147 or V700 Monocerotis) is a young stellar object in the constellation of Monoceros.

Location

HD 259431 lies in the northern portion of Monoceros, between Orion and Canis Minor, along with the spectacular Rosette Nebula and NGC 2264 region. It is half a degree from the faint IC 447 reflection nebula. HD 259431 is seen against NGC 2247, a small reflection nebula and star-forming region. It has been considered to be the illuminating source for the nebula, although it is uncertain if they are at the same distance. The Hipparcos annual parallax gives a distance of 170 parsecs while NGC 2247 is thought to be at about 800 parsecs, although both distances are somewhat uncertain. Many of its properties have been calculated assuming a distance of 800 parsecs, which means they are also highly uncertain. Gaia Data Release 3 gives a statistically precise distance around 650 parsecs.

Properties

HD 259431 is classed as a Herbig Haro Be star and has been instrumental in helping astronomers understand the formation of stars. A large star, with a large surrounding dust cloud, MWC 147 has given astronomers a clear picture of the mechanics of the accretion processes that form stars. Star MWC 147 was observed in the near and mid-infrared. The near-infrared studies showed dust matter at a temperature of several thousand kelvins in the innermost regions of the protoplanetary disk. In the mid-IR were lower temperatures. These observations showed that the disk around the star disk extends over 100 AU. The resulting research model assumes that the star increasing in mass at a rate 7×10−6 solar masses per year, or the equivalent of about two Earth masses per year. MWC has a mass of 6.6 M☉ and is younger than 500 000 years. This means that the life of this star is expected to be only about 35 million years. The star is found in the night sky at RA 06 h 33 m 05.19 and Dec 10° 19' 19.9869". It has a temperature of 14 125 K and spectral type of B6ep. It is also known as 2MJ06330519 + 1019199, HD 259431, HIP 31235 and SAO 95823.

References

External links It Takes A Very Large Telescope To See Inside MWC 147

Illustrations

Worked examples

Example 1 — a first encounter with HD 259431

Start with the simplest possible case. Write down what HD 259431 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 HD 259431 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 HD 259431 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 HD 259431

In research: HD 259431 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 HD 259431 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: HD 259431 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Durchmusterung objects, Henry Draper Catalogue objects, Herbig Ae/Be stars, so understanding it makes those chapters shorter.
In everyday life: Look for HD 259431 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 HD 259431 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 259431 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 HD 259431 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 259431 in simple terms?

HD 259431 (MWC 147 or V700 Monocerotis) is a young stellar object in the constellation of Monoceros. Location HD 259431 lies in the northern portion of Monoceros, between Orion and Canis Minor, along with the spectacular Rosette Nebula and NGC 2264 region.

Why does HD 259431 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 HD 259431?

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 HD 259431.