astronomy

NGC 1672

NGC 1672 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 NGC 1672 rather than just read about it. In short: NGC 1672 is a barred spiral galaxy located in the constellation Dorado. It was discovered by Scottish astronomer James Dunlop on 5 November 1826.

Key takeaways

NGC 1672 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NGC 1672 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 1672 from memory before moving on to harder problems.

Reference excerpt

NGC 1672 is a barred spiral galaxy located in the constellation Dorado. It was discovered by Scottish astronomer James Dunlop on 5 November 1826. It was originally unclear whether it was a member of the Dorado Group, with some sources finding it to be a member and other sources rejecting its membership. However, recent tip of the red-giant branch (TRGB) measurements indicate that NGC 1672 is located at the same distance as other members, suggesting it is indeed a member of the Dorado Group. NGC 1672 has a large bar which is estimated to measure around 20 kpc. It has very strong radio emissions emanating from its nucleus, bar, and the inner portion of the spiral arm region. The nucleus is Seyfert type II and is engulfed by a starburst region. The strongest polarized emissions come from the northeastern region which is upstream from its dust lanes. Magnetic field lines are at large angles with respect to the bar and turn smoothly to the center.

General structure The center of the galaxy contains a high surface brightness bar, and four filament-like spiral arms extend outward from the ends of this bar. The spiral arms are asymmetric; one of the arms in the northeast part of the disk is significantly brighter than its counterpart on the other side. The spiral arms also contain numerous star formation regions, some of which may be as large as 4″.

Nucleus The classification of the nucleus of NGC 1672 is uncertain. Most galaxies may be classified by their spectra as having one of three different types of nuclei:

A nuclear H II region, a region which has a spectrum similar to that of star formation regions in the Milky Way and which therefore is associated with nuclear star formation activity. A Seyfert nucleus, a type of active galactic nucleus (AGN) that may contain a supermassive black hole. A low-ionization nuclear emission-line region, a type of nuclear region with spectral line emission from weakly ionized gas that could contain either a star formation region or a supermassive black hole. NGC 1672, however, is one of several nearby galaxies that does not fit into this classification scheme, as its spectrum appears intermediary between these three classes of objects. It may in fact contain both nuclear star formation regions and an AGN. In some wave bands (such as in ultraviolet light), the star formation regions are the primary source of emission.

Supernovae Two supernovae have been observed in NGC 1672:

SN 2017gax (Type Ib/c, mag. 17.0406) was discovered by the Distance Less Than 40 Mpc Survey (DLT40) on 14 August 2017. SN 2022aau (Type II, mag. 16.2788) was discovered by DLT40 on 20 January 2022.

Gallery

See also NGC 1300 - A barred spiral galaxy. NGC 7552 - A very similar-looking barred spiral galaxy. List of NGC objects (1001–2000)

References

External links

Hubblesite Newscenter: Pictures and description

Illustrations

Worked examples

Example 1 — a first encounter with NGC 1672

Start with the simplest possible case. Write down what NGC 1672 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 NGC 1672 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 NGC 1672 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 NGC 1672

In research: NGC 1672 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 NGC 1672 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: NGC 1672 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1826, Barred spiral galaxies, Discoveries by James Dunlop, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 1672 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 NGC 1672 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 1672 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 NGC 1672 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 1672 in simple terms?

NGC 1672 is a barred spiral galaxy located in the constellation Dorado. It was discovered by Scottish astronomer James Dunlop on 5 November 1826.

Why does NGC 1672 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 NGC 1672?

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 NGC 1672.