astronomy

Pisces VII

Pisces VII 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 Pisces VII rather than just read about it. In short: Pisces VII (Psc VII), or Triangulum III (Tri III), is an ultra-faint dwarf galaxy and a possible satellite of the Triangulum Galaxy (Messier 33 or NGC 598). It is likely a small elliptical or irregular galaxy, and is one of the faintest objects within the Local Group, with an apparent magnitude of only 13.6.

Key takeaways

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

Reference excerpt

Pisces VII (Psc VII), or Triangulum III (Tri III), is an ultra-faint dwarf galaxy and a possible satellite of the Triangulum Galaxy (Messier 33 or NGC 598). It is likely a small elliptical or irregular galaxy, and is one of the faintest objects within the Local Group, with an apparent magnitude of only 13.6. It was first reported in 2020 by amateur astronomer Giuseppe Donatiello during a review of an astronomical survey, and was later confirmed by the Italian Galileo National Telescope, therefore making it first galaxy within the Local Group to have been discovered by an amateur astronomer.

Discovery Giuseppe Donatiello discovered Pisces VII in 2020 while analyzing the Dark Energy Camera Legacy Survey (DECaLS), a public astronomy survey conducted by the Cerro Tololo Inter-American Observatory using the Blanco 4m telescope. He reported it after identifying an unresolved over-density of stellar mass within the Pisces constellation; it was later confirmed by the Galileo National Telescope, making it the first Local Group object to have been discovered by an amateur astronomer.

Nomenclature Pisces VII or Triangulum III received both names from its location in the night sky; Pisces VII is derived from the galaxy's namesake constellation, Pisces, and is abbreviated as "Psc VII"; and Triangulum III, from its status as a suspected, unconfirmed satellite galaxy of Triangulum.

Characteristics Pisces VII is a small elliptical or irregular galaxy which is primarily composed of smaller, old red-dwarf stars, with a small population of younger blue giants; this has contributed to Pisces VII's unusually high apparent magnitude of 13.6±2, in spite of its relatively close proximity to Earth, and makes it one of the faintest objects within the Local Group at a solar luminosity of only 2.2×104 L☉, and an absolute magnitude of −6.1±2. It orbits 97 ± 6 kiloparsecs (316,372 ± 341.56 light years) away from Triangulum's galactic center, lying primarily within the galaxy's dark-matter halo. Due to the slightly warped structure of Triangulum, it is theorized that it made a close flyby with the Andromeda Galaxy within the past few billion years, and thus it is likely that much of the matter of Pisces VII was tidally stripped and pulled into Andromeda, leaving a much dimmer, fainter structure.

Observation

Pisces VII is visible in the namesake constellation of Pisces at a right ascension of 20h 25m 8.4s and a declination of 26° 23′ 27.6″, in the J2000 epoch. Due to its high magnitude, it cannot be seen with the naked human eye, and is extremely difficult to resolve and observe with amateur telescopes.

See also Giuseppe Donatiello List of Triangulum's suspected satellite galaxies Magellanic Clouds, dwarf satellite galaxies of the Milky Way Pisces II, dwarf satellite galaxy of the Milky Way

References

Illustrations

Worked examples

Example 1 — a first encounter with Pisces VII

Start with the simplest possible case. Write down what Pisces VII 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 Pisces VII 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 Pisces VII 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 Pisces VII

In research: Pisces VII 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 Pisces VII 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: Pisces VII is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 2020, Dwarf spheroidal galaxies, Local Group, so understanding it makes those chapters shorter.
In everyday life: Look for Pisces VII 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 Pisces VII in 20 minutes

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

Frequently asked questions

What is Pisces VII in simple terms?

Why does Pisces VII 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 Pisces VII?

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 Pisces VII.