science

SN H0pe

SN H0pe is a science 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 SN H0pe rather than just read about it. In short: SN H0pe (pronounced: Supernova Hope) is a Type Ia supernova discovered in 2023, at a redshift of z=1.78. It is a supernova discovered in a gravitationally lensed subject system, being itself a triply lensed object.

Key takeaways

SN H0pe belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SN H0pe to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SN H0pe from memory before moving on to harder problems.

Reference excerpt

SN H0pe (pronounced: Supernova Hope) is a Type Ia supernova discovered in 2023, at a redshift of z=1.78. It is a supernova discovered in a gravitationally lensed subject system, being itself a triply lensed object. Its name, H0pe, comes from its proposed utility in determination of the Hubble Constant (H0) that would allow determination of H0 in the distant universe and compare it with local determinations; and hopefully resolve Hubble tension, the difference in such determinations with local Type Ia supernovae and those based on the very distant Cosmic Microwave Background. The supernova exploded when the universe was 3.5 billion years old, rather than at today's date of 13.8 billion years old. The supernova progenitor was a white dwarf star, the progenitor of all Type Ia supernovae. The gravitational lens is galaxy cluster PLCK G165.7+67.0 (at a redshift of z=0.35), which lensed the supernova and its host galaxy.

The determination for the Hubble Constant (H0) using this Type Ia supernova was 75.4 kilometers per second per megaparsec. This greatly agrees with the determination of H0 with local Type Ia supernova of 73 kilometers per second per megaparsec. And this is at variance with the determination from the Cosmic Microwave Background and baryon acoustic oscillations, of 67 kilometers per second per megaparsec. Thus not resolving the Hubble tension, but instead reinforcing the difference. This determination of H0 from a multiply-lensed Type Ia supernova represents the first such precision measurement. The supernova is located in the galaxy PLCK G165.7+67.0 Arc 1 (Arc 1 for short) located at redshift z=1.78, behind the lensing cluster PLCK G165.7+67.0 (G165 for short) located at redshift z=0.35, and is triply imaged, each image called Arc 1a, Arc 1b, Arc 1c. This galaxy is part of a compact group of galaxies, of 6 members, 4 of which surround the host galaxy. This group 6 of galaxies is part of 11 galaxies that are imaged by the lens, each referred to as Arc 1, Arc 2, etc. The host galaxy is the dominant galaxy in its compact group. The lens system is located in the constellation of Ursa Major. The different images of the supernova arrived with a time delay. Images a and b had a time delay of Δtab=−116.6+10.8−9.3 observer-frame days. Images c and b had a time delay of Δtcb=−48.6+3.6−4.0 observer-frame days. Both measurements are relative to the last image to arrive (image 2b), meaning image a arrived around 117 days earlier than image b and image c arrived around 49 days earlier than image b.

References

External links NASA/IPAC Extragalactic Database (NED): PLCK G165.7+67.0 SIMBAD: (CNL2018) PLCK G165.7+67.0 lens -- Cluster of Galaxies

Illustrations

Worked examples

Example 1 — a first encounter with SN H0pe

Start with the simplest possible case. Write down what SN H0pe claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 SN H0pe 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 SN H0pe 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 SN H0pe

In research: SN H0pe appears in science 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 SN H0pe 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: SN H0pe is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2023 in outer space, Type Ia supernovae, Ursa Major, so understanding it makes those chapters shorter.
In everyday life: Look for SN H0pe 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.

Affiliate

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

How to study SN H0pe in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SN H0pe 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 SN H0pe out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SN H0pe in simple terms?

Why does SN H0pe matter?

Because it connects several science 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 SN H0pe?

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 SN H0pe.