astronomy

NGC 6907

NGC 6907 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 6907 rather than just read about it. In short: NGC 6907 is a spiral galaxy located in the constellation Capricornus. It is located at a distance of about 120 million light-years from Earth, which, given its apparent dimensions, means that NGC 6907 is about 115,000 light-years across.

Key takeaways

NGC 6907 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 6907 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 6907 from memory before moving on to harder problems.

Reference excerpt

NGC 6907 is a spiral galaxy located in the constellation Capricornus. It is located at a distance of about 120 million light-years from Earth, which, given its apparent dimensions, means that NGC 6907 is about 115,000 light-years across. It was discovered by William Herschel on July 12, 1784. The total infrared luminosity of the galaxy is 1011.03 L☉, and thus it is categorised as a luminous infrared galaxy.

Characteristics NGC 6907 is a grand design spiral galaxy with two spiral arms. It has an elliptical bulge that is skewed towards the base of the arms. The inner arms are bright and with knots, forming a bar. There are dust lanes in the arms. The disk of NGC 6907 is asymmetric. The eastern arm changes pitch angle and becomes linear after the location of the nearby galaxy NGC 6908. The western arm is less strong, but it is considerably longer, as its outermost parts form an arc with H II regions, wrapping nearly 360 degrees around the disk and forming a pseudoring. NGC 6907 also has a tidal tail with low surface brightness. The asymmetric tail extends from the north part of the disk of the galaxy towards the west and southwest. Its presence is an indicator of an ongoing unequal mass merger. The total HI mass of NGC 6907 is estimated to be (8.3±0.4)×109 M☉. NGC 6907 interacts with a low-luminosity lenticular galaxy, known as NGC 6908, that is superimposed on the eastern arm of NGC 6907, lying 40 arcseconds off the nucleus of NGC 6907. NGC 6908 was thought for many years to be actually part of NGC 6907, which was described as having two massive asymmetric arms; however, when observed in infrared, it becomes apparent NGC 6908 is a different galaxy. As NGC 6908 passed through the disk of NGC 6907, a stellar and gas bridge was formed between the two galaxies that has been observed as high-velocity gas. It is estimated that NGC 6908 passed through the disk approximately 35 million years ago.

Nearby galaxies NGC 6907 is the more prominent member of a small galaxy group known as the NGC 6907 group or LGG 436. Other members of the group, apart from NGC 6908, include IC 4999 and IC 5005. These two galaxies lie 61 and 74 arcminutes off NGC 6907, respectively. The group seems to form, with some other galaxies lying at similar redshift, like ESO 462- G016, a sheet of galaxies that extends 10 degrees in the sky, which corresponds to 7 Mpc at the distance of NGC 6907.

Supernovae NGC 6907 has been home to four supernovae:

SN 1984V (type unknown, mag 15.0) was discovered by L. E. Gonzalez on 29 May 1984. SN 2004bv (Type Ia, mag 15.6) was discovered by R. Kushida on 24 May 2004. SN 2008fq (Type II, mag 15.4) was discovered by the Lick Observatory Supernova Search (LOSS) on 15 September 2008. SN 2014eh (Type Ic, mag 16.0) was discovered by LOSS on 28 October 2014.

Gallery

See also NGC 1097 – another spiral galaxy with a smaller companion

References

External links

NGC 6907 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images NGC 6907 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with NGC 6907

Start with the simplest possible case. Write down what NGC 6907 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 6907 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 6907 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 6907

In research: NGC 6907 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 6907 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 6907 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1784, Barred spiral galaxies, Capricornus, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 6907 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 6907 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 6907 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 6907 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 6907 in simple terms?

Why does NGC 6907 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 6907?

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 6907.