astronomy

NGC 1316

NGC 1316 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 1316 rather than just read about it. In short: NGC 1316 (also known as Fornax A) is a lenticular galaxy about 60 million light-years (18.4 million parsecs) away in the constellation Fornax. It is a radio galaxy and at 1400 MHz the fourth-brightest radio source in the sky.

Key takeaways

NGC 1316 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 1316 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 1316 from memory before moving on to harder problems.

Reference excerpt

NGC 1316 (also known as Fornax A) is a lenticular galaxy about 60 million light-years (18.4 million parsecs) away in the constellation Fornax. It is a radio galaxy and at 1400 MHz the fourth-brightest radio source in the sky. It was discovered by Scottish astronomer James Dunlop on 2 September 1826.

Structure and formation In the late 1970s, François Schweizer studied NGC 1316 extensively and found that the galaxy appeared to look like an elliptical galaxy with some unusual dust lanes embedded within a much larger envelope of stars. The outer envelope contained many ripples, loops, and arcs. He also identified the presence of a compact disk of gas near the center that appeared inclined relative to the stars and that appeared to rotate faster than the stars (the mass-to-light ratio run in the center of NGC 1316 resembles that of many other giant ellipticals). Based on these results, Schweizer considered that NGC 1316 was built up through the merger of several smaller galaxies. Such merger events may have fueled the central supermassive black hole, that has a mass estimated in 130–150 million solar masses with gas, causing the galaxy to become a radio galaxy. He also states that NGC 1316 is comparable to the giant elliptical galaxies found in the centers of other clusters of galaxies. Using spectroscopy of its brightest globular clusters, the merger is estimated to have occurred ~3 billion years ago. NGC 1316 spans about 50 000 light-years. It has been proposed too that NGC 1316 may be a galaxy in evolution that eventually will become a Sombrero-like system dominated by a large bulge.

Companions and environment

NGC 1316 is located within the Fornax Cluster, a cluster of galaxies in the constellation Fornax. However, in contrast to Messier 87, which is a similar elliptical galaxy that is located in the center of the Virgo Cluster, NGC 1316 is located at the edge of the Fornax Cluster. NGC 1316 appears to be interacting with NGC 1317, a small spiral galaxy to the north. However, that small spiral galaxy does not appear to be sufficiently large enough to cause the distortions seen in the structure of this galaxy.

Distance estimates At least two methods have been used to estimate the distance to NGC 1316: surface brightness fluctuation (SBF) in 2003 and planetary nebula luminosity function (PNLF) in 2006. Being a lenticular galaxy, it is not suitable to apply the cepheid variable method; This is because Cepheids are typically massive, young stars, which lenticular galaxies lack the stellar resources to form. Using SBF, a distance estimate of 20.0 ± 1.6 Mpc was computed. Using PNLF, 45 planetary nebula candidates were located and a distance estimate of 17.9 +0.8−0.9 Mpc was computed. Averaged together, these two distance measurements give a combined distance estimate of 62.0 ± 2.9 Mly (19.0 ± 0.9 Mpc).[a]

Supernovae NGC 1316 has hosted four supernovae:

SN 1980N (Type Ia, mag. 14) was discovered by Marina Wischnjewsky on 30 November 1980. This is sometimes referred to as "Wischnjewsky's Supernova." SN 1981D (Type Ia, mag. 12.7) was discovered by Robert Evans on 10 March 1981. SN 2006dd (Type Ia, mag. 15) was discovered by Berto Monard on 19 June 2006. It got as bright as magnitude 12.1, making it the brightest supernova of 2006. SN 2006mr (Type Ia, mag. 15.6) was discovered by Berto Monard on 5 November 2006. For a brief period, both SN 2006dd and SN 2006mr were visible at the same time.

See also Centaurus A Messier 87 NGC 1097

Notes

Citations

External links

NASA Astronomy Picture of the Day: Central NGC 1316: After Galaxies Collide (25 January 2021) NASA Astronomy Picture of the Day: After Galaxies Collide (22 February 1999) NGC 1316 at ESA/Hubble

Illustrations

Worked examples

Example 1 — a first encounter with NGC 1316

Start with the simplest possible case. Write down what NGC 1316 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 1316 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 1316 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 1316

In research: NGC 1316 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 1316 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 1316 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Arp objects, Fornax, Fornax Cluster, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 1316 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 1316 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 1316 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 1316 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 1316 in simple terms?

Why does NGC 1316 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 1316?

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 1316.