Astrophysics (Index)About

transit method

(method of detecting exoplanets and binary companions)

The transit method is a method of detecting extra-solar planets by looking for variability in a star's light that indicates a transit. It is arguably the easiest and most effective and the vast majority of known exoplanets were found using transits. The technology required is the sensitivity for precise measurement of the star's brightness (magnitude), and automation to keep watching the star. If a star dims repeatedly by the same amount with the precisely the same lengths of time dimmed and lengths of time between, the presence of an object with an orbit such that the object passes between the star and the Earth is the only viable explanation. The object can be a planet or a binary companion; the technique is also used to discover binary stars and when any repeating transit is uncovered, it is necessary to determine which of these has been found. Starspots can mimic them for a limited time but eventually lose the pattern of variation.

Automation is not strictly necessary but practically speaking, it is a major factor in the development and success of the transit method, both to operate the telescope repeatedly and to analyze the data for signs of a planet. The largest telescopes are not necessary, and surveys aiming to find planets have been successful using small telescopes. Ground telescope surveys include WASP and the MEarth Project, and space-based surveys include Kepler and TESS.


(exoplanets,transits)
Further reading:
https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets#Transit_photometry
https://en.wikipedia.org/wiki/Astronomical_transit
https://en.wikipedia.org/wiki/List_of_transiting_exoplanets
https://lco.global/spacebook/exoplanets/transit-method/
https://exoplanets.nasa.gov/faq/31/whats-a-transit/
https://www.nasa.gov/kepler/overview/abouttransits

Referenced by pages:
airmass
EXOFAST
exosatellite
extra-solar planet
giant planet formation
GJ 1132 b
GJ 1214 b
GPX
HAT-P-7b
K2-18b
Kepler-1625b
Kepler-16b
Kepler-186f
Kepler-452b
LHS 3844 b
light curve
occultation
PLATO
radial velocity method
SPECULOOS
stellar activity
stripped star
TOI 700 d
transient astronomy
transit
transiting planet
WASP
WASP-12b
WASP-33b
WASP-43b
WASP-67b
XO-3b

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