astronomy

HD 141569

HD 141569 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 HD 141569 rather than just read about it. In short: HD 141569 is an isolated Herbig Ae/Be star of spectral class A2Ve approximately 364 light-years away in the constellation of Libra. The primary star has two red dwarf companions (orbiting each other) at about nine arcseconds.

Key takeaways

HD 141569 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HD 141569 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 141569 from memory before moving on to harder problems.

Reference excerpt

HD 141569 is an isolated Herbig Ae/Be star of spectral class A2Ve approximately 364 light-years away in the constellation of Libra. The primary star has two red dwarf companions (orbiting each other) at about nine arcseconds. In 1999, a protoplanetary disk was discovered around the star. A gap in the disk led to speculation about a possible extrasolar planet forming in the disk. In November 2019, researchers studied HD 141569A (pre-main sequence B9.5 star) and made the first polarimetric detection of the inner ring circling the star. This may help better determine essential features of planetary development. According to the researchers, "Considering resolved imaging data from other high-contrast facilities, the HD 1415169A debris disc shapes up to be made of at least three, and potentially four nested rings, with spiral structures on the three spatially resolved rings [...] As such, it is an excellent laboratory for studying dynamically perturbed discs."

Planetary system

Protoplanetary disk In January 1999, NASA announced a protoplanetary disk around HD 141569. The Hubble Space Telescope showed that the disk appears to come in two parts (inner and outer). It superficially resembles the largest gap in Saturn's rings (known as the Cassini division). The vast disk is 75 billion miles across (13 times the diameter of Neptune's orbit). The inner edge of the gap is 21 billion miles from the star. The relatively narrow gap lies approximately halfway between the inner and outer edges of the disk. Though already a fully formed star, HD 141569 is relatively young, probably only 1% through its lifetime as a stable star. The star is nearly three times more massive and 22 times brighter than the Sun.

HD 141569 was first identified as a source that might have a disk in 1986 as a result of observations done with the Infrared Astronomical Satellite (IRAS). Thermal radiation emitted by the warmed dust was observed in images taken in June 2016 at the W. M. Keck Observatory. Light from the central star which was reflected from dust particles in the disk was captured by Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) at a wavelength of 1.1 micrometres. At the distance of HD 141569, the crisp resolution of the telescope and camera combination reveals structures as small as 1 billion miles across. Dust disks surrounding newly forming stars are common, but only a small number of adult stars are known to have disks; of these, only a handful have been imaged. Astronomers believe these disks must form and/or be replenished when older rocks and debris collide and break up into small particles. The inner disk is strongly asymmetric for reasons unknown as of 2021. About 1 AU from the star, a faint dust ring was detected in 2021.

Possible planet The gap in the disk leads to the conclusion of a protoplanet in formation around the star. The planet does not have to be in the gap, however. It could either be sweeping up the dust and rocks from the disk as it travels in its orbit around the star, or the gravity of the planet could knock the dust out of one part of the disk.

Illustrations

Worked examples

Example 1 — a first encounter with HD 141569

Start with the simplest possible case. Write down what HD 141569 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 HD 141569 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 HD 141569 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 HD 141569

In research: HD 141569 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 HD 141569 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: HD 141569 is common in secondary-school and first-year university syllabi. It links to neighbouring topics A-type main-sequence stars, Circumstellar disks, Durchmusterung objects, so understanding it makes those chapters shorter.
In everyday life: Look for HD 141569 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “HD 141569” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study HD 141569 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 141569 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 HD 141569 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 141569 in simple terms?

Why does HD 141569 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 HD 141569?

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 HD 141569.