science

WD 1647+375

WD 1647+375 is a science 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 WD 1647+375 rather than just read about it. In short: WD 1647+375 (WD J164920.30+372821.25, PG 1647+376) is a DA2.2 type white dwarf located approximately 256 light-years from Earth in the constellation Hercules. This star has a mass of 0.57 M☉ and a radius of 0.0144 R☉.

Key takeaways

WD 1647+375 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect WD 1647+375 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of WD 1647+375 from memory before moving on to harder problems.

Reference excerpt

WD 1647+375 (WD J164920.30+372821.25, PG 1647+376) is a DA2.2 type white dwarf located approximately 256 light-years from Earth in the constellation Hercules. This star has a mass of 0.57 M☉ and a radius of 0.0144 R☉. As it is a white dwarf – the remnant of a stellar core, its temperature will be high, specifically 22040 K. The log(g) gravity on the surface of this object is 7.88 cgs, and its age is 30 million years.

Icy Exoplanetesimal

In September 2025, a group of astronomers, led by researchers from the University of Warwick (UK), utilized data from the Hubble Space Telescope, STIS and the ground-based VLT telescope. Analysis of the ultraviolet spectrum revealed interesting details. The white dwarf WD 1647+375 was quite different from others of its kind. It stood out due to the presence of volatile substances on its surface. The atmosphere of white dwarfs typically consists of hydrogen and helium, but in this case, elements such as carbon, nitrogen, sulfur, and oxygen were detected. Furthermore, ultraviolet spectroscopy, used in the study, revealed a high percentage of nitrogen in the material accreted by the star, specifically ~5%. Additionally, the atmosphere of WD 1647+375 also contains significantly more oxygen, approximately 84% more, than would be expected. All of this indicated the presence of an icy object in the system, designated as WD 1647+375 b. Astronomers had data indicating that the debris had been feeding the star for at least the past 13 years at a rate of 200,000 kg per second. This meant the icy object had a diameter of 3 to 50 km and could have weighed a quintillion kilograms. In total, these data provided insight into an icy/water-rich planetesimal (composed of 64% water) being consumed by its parent star, possibly a comet similar to Halley's Comet, or a fragment of a dwarf planet, like C/2016 R2. This object can be compared to Kuiper Belt Objects (KBOs) in our Solar System. This planetesimal is most likely a fragment of a dwarf planet, such as Pluto.

References

Illustrations

Worked examples

Example 1 — a first encounter with WD 1647+375

Start with the simplest possible case. Write down what WD 1647+375 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 WD 1647+375 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 WD 1647+375 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 WD 1647+375

In research: WD 1647+375 appears in science 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 WD 1647+375 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: WD 1647+375 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Circumstellar disks, Hercules (constellation), White dwarfs, so understanding it makes those chapters shorter.
In everyday life: Look for WD 1647+375 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 WD 1647+375 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what WD 1647+375 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 WD 1647+375 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is WD 1647+375 in simple terms?

Why does WD 1647+375 matter?

Because it connects several science 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 WD 1647+375?

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 WD 1647+375.