astronomy

V392 Persei

V392 Persei 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 V392 Persei rather than just read about it. In short: V392 Persei, also known as Nova Persei 2018, is a bright nova in the constellation Perseus discovered on April 29, 2018. It was previously known as a dwarf nova.

Key takeaways

V392 Persei belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect V392 Persei to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of V392 Persei from memory before moving on to harder problems.

Reference excerpt

V392 Persei, also known as Nova Persei 2018, is a bright nova in the constellation Perseus discovered on April 29, 2018. It was previously known as a dwarf nova.

Dwarf nova A U Geminorum-type variable star or dwarf nova is a type of cataclysmic variable star consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from a cool main sequence or subgiant companion. V392 Persei was discovered in 1970 and received its variable star designation a year later. It is normally visual magnitude 17.4 and experiences outbursts of 2-3 magnitudes. Its spectrum in the quiescent state has been studied and only the cool star is detected. The spectrum shows emission lines of hydrogen-alpha (Hα) and both neutral and ionised helium. The brightest recorded observations is at magnitude 5.6.

Nova eruption

On April 29, 2018 it was discovered by Yuji Nakamura to be extremely bright, and it was spectroscopically confirmed as a nova outburst with magnitude 6.2 on April 30. The spectrum includes broad Hα and FeII emission lines with P Cygni profiles. The absorption core is blueshifted by a velocity of 2,680 km/s, which would be the expansion velocity from the nova explosion. Observations with Fermi-LAT on April 30 show a strong gamma-ray source at the coordinates of the nova. Photometry of the nova from Konkoly Observatory on May 1, 2018 give apparent magnitudes of 7.38 in the V band and 8.22 in the B band, suggesting it is already declining.

System V392 Persei is the southern of a pair of stars separated by 8.5". The symbiotic pair are unresolved, with an orbital period of only 3.21997 days, and the nature of the cool component is unclear. The spectral energy distribution is inconsistent with a bright giant star but it could be less luminous red clump giant or subgiant. If the cool component was a main sequence red dwarf as expected for a dwarf nova, then the system would need to be closer than the 13,000 ly suggested by its Gaia parallax.

Gallery

See also List of novae in the Milky Way galaxy

References

External links Dwarf Nova V392 Persei Goes Big — It’s Now Binocular Bright How A Dwarf Nova Hit The Big Time May 2, 2018 Nova in Perseus V392 Per in outburst, showing spectra of the nova in outburst and previously

Illustrations

Worked examples

Example 1 — a first encounter with V392 Persei

Start with the simplest possible case. Write down what V392 Persei 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 V392 Persei 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 V392 Persei 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 V392 Persei

In research: V392 Persei 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 V392 Persei 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: V392 Persei is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 2018, Double stars, Dwarf novae, so understanding it makes those chapters shorter.
In everyday life: Look for V392 Persei 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 V392 Persei in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what V392 Persei 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 V392 Persei out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is V392 Persei in simple terms?

V392 Persei, also known as Nova Persei 2018, is a bright nova in the constellation Perseus discovered on April 29, 2018. It was previously known as a dwarf nova.

Why does V392 Persei 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 V392 Persei?

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 V392 Persei.