Planets found by transit
4,708 of the confirmed exoplanets in this catalog, 74% of the total, were found by the transit method: watching a star dim as a planet crosses in front of it, the first of them in 2002.
A transit is a miniature eclipse. If a planet's orbit happens to be edge-on from our point of view, the planet passes across the face of its star once per orbit and blocks a small fraction of the light: about one percent for a Jupiter-sized planet, less than one part in ten thousand for an Earth. Measure that dip precisely enough, repeatedly, and you have a planet, its orbital period, and its size as a direct ratio to the star's.
This is the method that built the modern catalog. Kepler stared at a single patch of sky for four years and found thousands of candidates; TESS now scans almost the whole sky in sectors. A transit alone gives a size but not a mass, which is why the best-understood planets are the ones that transit and also show a measurable wobble: together the two give a density, and a density is the closest thing to knowing what a world is made of.
Geometry. A planet only transits if its orbit lines up with our line of sight, which for an Earth-like orbit around a Sun-like star happens for about one system in two hundred. The other 199 have planets we cannot see this way, so a transit survey measures a slice of the sky rather than a census of it.
| # | World | Distance | Discovered |
|---|---|---|---|
| 1 | LTT 1445 A b | 22.4 ly | 2019 |
| 2 | LTT 1445 A c | 22.4 ly | 2022 |
| 3 | GJ 367 b | 30.7 ly | 2021 |
| 4 | GJ 357 b | 30.8 ly | 2019 |
| 5 | AU Mic b | 31.7 ly | 2020 |
| 6 | AU Mic c | 31.7 ly | 2021 |
| 7 | HD 260655 b | 32.6 ly | 2022 |
| 8 | HD 260655 c | 32.6 ly | 2022 |
| 9 | GJ 341 b | 34.1 ly | 2025 |
| 10 | L 98-59 b | 34.6 ly | 2019 |
| 11 | L 98-59 c | 34.6 ly | 2019 |
| 12 | L 98-59 d | 34.6 ly | 2019 |
| 13 | GJ 806 b | 39.3 ly | 2023 |
| 14 | Gliese 12 b | 39.8 ly | 2024 |
| 15 | TRAPPIST-1 b | 40.5 ly | 2016 |
| 16 | TRAPPIST-1 c | 40.5 ly | 2016 |
| 17 | TRAPPIST-1 d | 40.5 ly | 2016 |
| 18 | TRAPPIST-1 e | 40.5 ly | 2017 |
| 19 | TRAPPIST-1 f | 40.5 ly | 2017 |
| 20 | TRAPPIST-1 g | 40.5 ly | 2017 |
| 21 | TRAPPIST-1 h | 40.5 ly | 2017 |
| 22 | LHS 475 b | 40.7 ly | 2023 |
| 23 | GJ 1132 b | 41.1 ly | 2015 |
| 24 | HD 101581 b | 41.7 ly | 2025 |
| 25 | HD 101581 c | 41.7 ly | 2025 |
Showing the 25 nearest of 4,693 with a measured distance.
How does the transit method find planets?
4,708 of the confirmed exoplanets in this catalog, 74% of the total, were found by the transit method: watching a star dim as a planet crosses in front of it, the first of them in 2002.
What was the first planet found by the transit method?
OGLE-TR-56 b, confirmed in 2002. The method has found 4,708 confirmed worlds since, the most recent of them in 2026.
What can this method not see?
Geometry. A planet only transits if its orbit lines up with our line of sight, which for an Earth-like orbit around a Sun-like star happens for about one system in two hundred. The other 199 have planets we cannot see this way, so a transit survey measures a slice of the sky rather than a census of it.
How much does a star dim during a transit?
By the ratio of the two areas. A Jupiter-sized planet blocks about 1% of a Sun-like star, which a good amateur setup can detect. An Earth-sized planet blocks 0.008%, which needs a space telescope above the atmosphere's turbulence.
Can you see a transit from Earth with a telescope?
The deep ones, yes. Amateur astronomers routinely record hot Jupiters transiting bright stars, and their measurements are used to refine orbital timings. The small-planet transits that Kepler found are far beyond ground-based reach.
Keep exploring: every detection method · the term itself · discoveries by year