Planetary system · 1 known planet · Cygnus

Kepler-22

Its star: above the horizon all nightHighest after dark 20:20 · west · 80°

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Where is Kepler-22?

Times for LondonChange city

Look west, about 80° up at 20:20 in Cygnus.

Rises: Always up
Highest: 19:20
Sets: Never
Best after dark: 20:20 · 80°

Can I see Kepler-22?

No. The planets of Kepler-22 can’t be seen with the eye, binoculars or any amateur telescope: they are lost in their star’s light. What you can do is point toward the star.

From London tonight, the star Kepler-22 is above the horizon all night. It’s highest soon after dark, around 20:20, in the west at 80°.

Why is Kepler-22 interesting?

Kepler-22 has 1 known planet, discovered in 2011 by the primary transit method.

What can you see?

Eyes

Direction only

Not visible.

Binoculars

Not visible.

Telescope

The star is around magnitude 12 and needs a telescope of about 150 mm and a detailed chart. The planets themselves can’t be seen with any backyard telescope.

What you’re likely to see, not what a space telescope photographs.

About

Kepler-22 is a Sun-like star about 640 light-years away in Cygnus. In 2011, its planet Kepler-22 b became the first planet found by NASA’s Kepler mission in a star’s habitable zone.

Kepler-22 b is about 2.4 times the width of Earth and orbits every 290 days. Its composition is unknown: it could be a rocky world, a water world or a small gas-rich planet.

Its star is slightly smaller and cooler than the Sun. The planet was confirmed in 2011 after Kepler saw it pass in front of its star three times.

The habitable zone is the range of distances where a planet could, in principle, have liquid water on its surface. Being in that zone doesn’t mean a planet has water or life: that depends on its size, atmosphere and history.

Kepler-22 b sits between Earth and Neptune in size, a common kind of planet in our galaxy that our Solar System lacks.

The Kepler-22 system

Known planets of Kepler-22 (catalog values from exoplanet.eu)
Planet	Mass	Radius	Orbit	From star	Found	Method
Kepler-22 b	9.09 M⊕	2.10 R⊕	289.9 days	0.812 AU	2011	Primary Transit

M⊕ / R⊕ = Earth masses / radii; M♃ / R♃ = Jupiter. Masses from radial velocity are often minimum masses. Data: The Extrasolar Planets Encyclopaedia, exoplanet.eu (CC BY 4.0).

Questions

Is Kepler-22 b a rocky planet?

We don’t know. Its size is between Earth and Neptune, and its mass hasn’t been measured precisely.

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Sources: The Extrasolar Planets Encyclopaedia (CC BY 4.0); star chart: Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences