astronomy

HD 115404

HD 115404 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 115404 rather than just read about it. In short: HD 115404 is a binary star system located in the constellation Coma Berenices. Parallax measurements made by Hipparcos put the system at 36 light-years, or 11 parsecs, away.

Key takeaways

HD 115404 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 115404 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 115404 from memory before moving on to harder problems.

Reference excerpt

HD 115404 is a binary star system located in the constellation Coma Berenices. Parallax measurements made by Hipparcos put the system at 36 light-years, or 11 parsecs, away. The combined apparent magnitude of the system is 6.52, with the magnitudes of the components being 6.66 and 9.50. The primary component, designated A, is a K-type main sequence star. It is about 70% as massive as the Sun, and is 0.76 times as wide. Its companion is a red dwarf (M0.5 V). It has 54.2% the mass of the Sun, and is 0.55 times as wide. The two stars orbit each other every 770 years, and are separated by about 8″. The system is thought to be fairly old, at 5.4 to 13.5 billion years old. In 2022, two exoplanets, Neptunian and super-Jovian in mass, were reported in orbit around the primary star using a combination of radial velocity and astrometry. However, a 2025 study using radial velocity observations failed to detect these planets.

References

Worked examples

Example 1 — a first encounter with HD 115404

Start with the simplest possible case. Write down what HD 115404 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 115404 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 115404 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 115404

In research: HD 115404 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 115404 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 115404 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Binary stars, Coma Berenices, Durchmusterung objects, so understanding it makes those chapters shorter.
In everyday life: Look for HD 115404 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 115404 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 115404 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 115404 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 115404 in simple terms?

HD 115404 is a binary star system located in the constellation Coma Berenices. Parallax measurements made by Hipparcos put the system at 36 light-years, or 11 parsecs, away.

Why does HD 115404 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 115404?

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 115404.