Kepler-737b

Key takeaways

Kepler-737b belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kepler-737b to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kepler-737b from memory before moving on to harder problems.

Reference excerpt

Kepler-737b is a super-Earth exoplanet 669 light years away. There is a chance it could be on the inner edge of the habitable zone.

Physical properties

Mass, radius and temperature Kepler-737b is an exoplanet with 1.96 R🜨 (0.175 RJ). Its mass is unknown, but is estimated at 4.5 M🜨 based on a mass-radius relationship. If the 4.5-earth mass estimate is correct, this gives the planet an approximate density of 3.3 times that of water, giving it the possibility of being a mini-Neptune or, more favorable to habitability, a water world. Due to its stellar flux 121% that of Venus, it may be a smaller version of GJ 1214b, a classic superpressured water world. The planet's equilibrium temperature is 298 K (25 °C).

Star The star's designations include Kepler-737 and KOI-947. It is an early M-star. The mass is 0.51 solar masses and its radius is 0.48 times that of the Sun. The temperature of the star is 3813 K and its metallicity is -0.24, significantly lower than the Sun's. The host star's age is 3.89 billion years, 680 million years younger than the Sun.

Orbit Kepler-737b orbits its star once every 28.5992 days. It may be within the inner part of the habitable zone, depending on the habitable zone model used. The conservative model/models place it over 1 Earth flux level outside of the habitable zone, but some very optimistic models place it inside the far inner section of the extended habitable zone. If it is not a mini-Neptune, then it might have a small chance of being habitable. It would be substantially hotter than Earth, due to its stellar flux 2.297 times that of Earth, greater than that of Venus, and resulting equilibrium temperature of 298 K (25 °C; 77 °F).

Discovery Kepler-737b is a confirmed exoplanet that was found by Kepler using the transit method. It was confirmed on May 10, 2016.

Nomenclature Kepler-737b is also known as KOI-947.01, KIC 9710326 b, and Gaia DR2 2126820324123177472 b. KOI means "Kepler Object of Interest" and KIC means "Kepler Input Catalog". Gaia is a European satellite that was launched on December 19, 2013.

Habitability

With a stellar flux 2.297 times that of Earth, greater than that of Venus, Kepler-737b is unlikely to be habitable. However, Kepler-737b is considered to be in the habitable zone by the Open Exoplanet Catalogue, based on an extremely optimistic habitable zone model that also places Venus in the habitable zone. Due to its equilibrium temp. of 298 K, with and earth-like GE it would be about sixty degrees Celsius, and with twice its GE, ninety degrees. It is likely tidally locked due to its short orbit; a tidally locked planet would have one side facing the star permanently while the other would be in constant darkness. If Kepler-737b has little or no atmosphere, this could make one side too hot to live on, and the other too cold. However, there may be a "sweet spot" in between the two, where liquid water can exist. This spot would be the planet's terminator line. Kepler-737b may instead have atmospheric circulation that would distribute the heat around the planet, potentially making a large portion of it habitable, although given its stellar flux the most likely scenario is that the planet's surface is too hot to be habitable. Water on Kepler-737b's surface could also distribute heat. Kepler-737b's density is unknown, so it could either be a rocky super-Earth or a mini-Neptune. The fact that the planet is quite likely to have no magnetic field could spark adaptations to the relatively high radiation level, such as a thick shell of a substance that could repel the radiation or tardigrade-like DNA. In most earthly creatures, DNA is damaged permanently, but with tardigrades, DNA is repairable after being damaged by deadly radiation. There is a reduced chance of intelligent life on Kepler-737b due to the fair chance that it is a water world, with no dry land. It is likely substantially hotter than Earth, due to its stellar flux 2.297 times that of Earth and resulting equilibrium temperature of 298 K (25 °C; 77 °F). If ice caps exist, then they would likely be much smaller than Earth's, due to the temperature as well as to the possibility that Kepler-737b has more carbon dioxide in its atmosphere than Earth. It would have accreted the carbon dioxide by gravity or because water worlds are likely to have a lot of carbon dioxide in their atmospheres. More carbon dioxide in an atmosphere equalizes the temperature.

See also Kepler-186f, a habitable zone exoplanet around an early M-star. Ross 128 b, an exoplanet orbiting a quiet red dwarf. TRAPPIST-1, an ultra-cool dwarf with 7 planets, 4 of which are potentially habitable: TRAPPIST-1d TRAPPIST-1e TRAPPIST-1f TRAPPIST-1g Gliese 832 c, another Super-Earth exoplanet with a relatively high stellar flux and a small chance of being habitable. Desert planet Gliese 1214b, a possible water world. Kepler-22b, another possible water world that, unlike GJ 1214b, orbits in the habitable zone. Ocean world

Notes

References

External links

KOI-947.01 in SIMBAD

Worked examples

Example 1 — a first encounter with Kepler-737b

Start with the simplest possible case. Write down what Kepler-737b 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 Kepler-737b 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 Kepler-737b 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 Kepler-737b

In research: Kepler-737b 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 Kepler-737b 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: Kepler-737b is common in secondary-school and first-year university syllabi. It links to neighbouring topics Exoplanets discovered by the Kepler space telescope, Exoplanets discovered in 2016, Super-Earths, so understanding it makes those chapters shorter.
In everyday life: Look for Kepler-737b 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.

How to study Kepler-737b in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kepler-737b 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 Kepler-737b out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kepler-737b in simple terms?

Kepler-737b is a super-Earth exoplanet 669 light years away. There is a chance it could be on the inner edge of the habitable zone.

Why does Kepler-737b 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 Kepler-737b?

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 Kepler-737b.