astronomy

NGC 1

NGC 1 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 1 rather than just read about it. In short: NGC 1 is an intermediate spiral galaxy of the morphological type Sbc, located in the constellation of Pegasus. It was discovered on 30 September 1861 by Heinrich d'Arrest.

Key takeaways

NGC 1 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 1 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 1 from memory before moving on to harder problems.

Reference excerpt

NGC 1 is an intermediate spiral galaxy of the morphological type Sbc, located in the constellation of Pegasus. It was discovered on 30 September 1861 by Heinrich d'Arrest.

Observation history Heinrich d'Arrest discovered NGC 1 on 30 Sep 1861 while testing the 11-inch f/17.5 Merz refractor of the Copenhagen Observatory. He missed nearby NGC 2. This was d'Arrest's first deep sky discovery, though he was uncertain if his object was identical to h4 or h5 (both of which refer to NGC 16). His descriptions (combination of 4 observations) read "faint, small, round, 20", no concentration. In a straight line connecting two stars 11 and 14 mag." Herman Schultz observed NGC 1 three times in 1866 and 1868 with a 9.6-inch refractor at Uppsala and he also missed fainter NGC 2. The NGC 1 and 2 pair are not physically related. NGC 1 lies at a distance of about 200 million light-years (61 Mpc) with NGC 2 at roughly 320 million light-years (98 Mpc). The initial observers missed NGC 2, which is much fainter. NGC 1 appears to be quite close to NGC 2, in reality however, the two objects are far apart and unrelated. NGC 2 was first observed as a "companion" of NGC 1 by Lawrence Parsons.

Properties

At an estimated 140,000 light-years in diameter, NGC 1 is roughly the same size as our galaxy, the Milky Way, which is believed to be approximately 160,000 light-years across. Although its apparent magnitude of 13.65 makes the galaxy appear too faint to see with the naked eye, its absolute magnitude of -22.08 makes NGC 1 two to three times more luminous than our home galaxy. The galaxy is 4.0 Mly away from the 80,000 light-years wide galaxy UGC 69, its nearest major neighbor. NGC 1 has a visual size of 1.6' × 1.2'. Being classified as a SABbc class galaxy using the Hubble sequence and the De Vaucouleurs system as an extension, NGC 1 is a spiral galaxy with the presence of a weak nuclear bar and loosely wound arms. Although the central galaxy is only about 90,000 light-years across, a large, diffuse arm extends eastwards from it, possibly from a past merger. Based on its redshift of approximately 0.015177 and thus recessional velocity of 4450 km/s, the distance of the galaxy from the Solar System can be calculated using Hubble's law. Using current observation data, this places the galaxy at approximately 210 to 215 million light-years from Earth, which is in good agreement with redshift-independent distance estimates of 175 to 245 million light years. An opposing measurement of the galaxy's recessional velocity of 2215 km/s would place the galaxy only about 100 million light-years away. However, this is regarded unlikely by most astronomers and believed to be a misattributed value for a different galaxy.

Listing in astronomical catalogues After being logged as the first object in the General Catalogue, the galaxy is also the first object to be listed in the catalogue's successor, the New General Catalogue. With an original right ascension of 00h 00m 4s at the time of the catalog's compilation (epoch 1860), this object had the lowest right ascension of all the objects in the catalog, making it the first listing in the New General Catalogue as the objects were arranged by right ascension. Since then, the coordinates have shifted, and this object no longer has the lowest right ascension of all the NGC objects.

NGC 23 group NGC 1 is part of the NGC 23 group (also known as LGG 2) that includes at least 6 other galaxies: NGC 23, NGC 26, UGC 69, UGC 79, UGC 110, and UGC 127.

See also Pegasus (constellation) List of NGC objects (1–1000) List of NGC objects Spiral galaxy

References

External links

NGC 1 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images SEDS

Illustrations

Worked examples

Example 1 — a first encounter with NGC 1

Start with the simplest possible case. Write down what NGC 1 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 1 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 1 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 1

In research: NGC 1 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 1 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 1 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1861, Discoveries by Heinrich Louis d'Arrest, Galaxies discovered in 1861, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 1 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 1 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 1 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 1 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 1 in simple terms?

NGC 1 is an intermediate spiral galaxy of the morphological type Sbc, located in the constellation of Pegasus. It was discovered on 30 September 1861 by Heinrich d'Arrest.

Why does NGC 1 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 1?

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 1.