"The first confirmation of the detection occurred in 1992."
Study of the orbital and gravitational interactions between exoplanets and their host stars, as well as other planets in the same system.
Orbital mechanics: Understanding the laws of motion and how they apply to the motion of planets around stars.
Transit and radial velocity methods: The two primary methods for detecting exoplanets.
Planetary formation: The process by which planets are born from protoplanetary disks.
Stellar evolution: How stars change over time and how that can affect the planets around them.
Habitability and biosignatures: The conditions required for life to exist and the potential signs of life on other planets.
Kepler's laws: The three laws that describe how planets move in their orbits.
Tides and gravitational interactions: How the gravitational forces of planets and stars can affect one another.
Stability and chaos: Exploring the stability of planetary systems and the potential for chaotic motion.
Atmospheric dynamics: The movement of gases in a planet's atmosphere and how it can affect the planet's climate.
Spectroscopy: A technique for analyzing the chemical makeup of exoplanet atmospheres and determining their properties.
Planet-star interactions: How exoplanets interact with their host stars, including magnetic fields and radiation.
Exoplanet atmospheres: The study of the composition and structure of the atmospheres of exoplanets.
Planetary migration: The movement of planets within a planetary system over time.
Direct imaging: Imaging of exoplanets directly, typically in the infrared spectrum, to provide a greater understanding of their properties.
Planetary system architecture: The structure and arrangement of planets in a particular system.
Planetary system dynamics: How the dynamics of a planetary system can evolve over time.
Planetary statistics: Statistical analysis of exoplanet data to identify trends and patterns.
Planetary characterization: The process of determining the properties of exoplanets.
Occurrence rate: An estimate of how many exoplanets are likely to exist in our galaxy.
Radial velocity simulations: The use of computer simulations to study the motion of exoplanets and their host stars.
Transit timing variations: The detection of minor variations in the timing of exoplanet transits, which can provide information about the planetary system.
Planet-star obliquity: The angle between the planet's orbital plane and the host star's rotational axis.
Binary star systems: The study of planetary systems in which the host star is part of a binary star system.
Astrobiology: The interdisciplinary field of study that explores the potential for life on other planets.
Planetary atmospheres and climate: The study of atmospheric dynamics and climate on exoplanets.
Transit Timing Variations (TTV): When an exoplanet passes in front of its host star, it blocks some of the star's light, causing a dip in brightness. However, the transit time can vary, giving hints about the planet's gravity and the presence of other planets in the same system.
Radial Velocity (RV): Planets orbit stars, and that means the star will wobble ever so slightly due to the planet's gravitational pull. By measuring these tiny shifts in starlight, astronomers can determine the planet's mass, size and orbit.
Astrometry: Astrometry is the measurement of a star's position and motion in the sky. As planets orbit their host star, the star will also move, and astrometry can detect this motion. Additionally, astrometry can detect how much the exoplanet is tilting or tipping on its axis.
Transit Photometry: When an exoplanet passes in front of its host star, it causes a dip in the star's brightness. This dip can be detected by measuring changes in the star's light output. Transit photometry can reveal the size and composition of orbiting exoplanets.
Gravitational Microlensing: This phenomenon occurs when a massive object, such as a star, passes in front of a distant star, bending the distant star's light. If an orbiting exoplanet happens to be in between the two stars, it too can cause a slight gravitational lensing effect.
Direct Imaging: Direct imaging is the observation of an exoplanet through a telescope. This can reveal the planet's size, composition and even its atmosphere.
Pulsar Timing: Pulsars are rapidly spinning neutron stars that emit beams of radiation at regular intervals. By tracking the timing of these pulses, astronomers can detect the presence of orbiting exoplanets by observing subtle variations in the pulse timings.
Orbital Resonance: When two or more exoplanets orbit a star, their gravitational forces can cause them to fall into orbital resonance, where their orbital periods are related by simple fractions. This phenomenon can reveal a lot about the planets' masses and orbits.
Dynamical Tides: As exoplanets orbit their host star, they can experience tidal forces due to differences in gravitational pull on either side of the planet. This can lead to variations in the planet's shape and even its rotation.
Roche Limit: The Roche limit is the distance from a planet at which the tidal forces exerted by a star are stronger than the planet's own gravitational forces. If a planet orbits too close to its star, it can be torn apart by these tidal forces.
"As of 1 September 2023, there are 5,506 confirmed exoplanets."
"with 878 systems having more than one planet."
"The James Webb Space Telescope (JWST) is expected to discover more exoplanets, and also much more about exoplanets, including composition, environmental conditions, and potential for life."
"Transit photometry and Doppler spectroscopy have found the most."
"85% of the exoplanets detected are inside the tidal locking zone."
"About 1 in 5 Sun-like stars have an 'Earth-sized' planet in the habitable zone."
"...it can be hypothesized that there are 11 billion potentially habitable Earth-sized planets in the Milky Way, rising to 40 billion if planets orbiting the numerous red dwarfs are included."
"The least massive exoplanet known is Draugr, which is about twice the mass of the Moon."
"The most massive exoplanet listed on the NASA Exoplanet Archive is HR 2562 b, about 30 times the mass of Jupiter."
"Known orbital times for exoplanets vary from less than an hour (for those closest to their star) to thousands of years."
"However, there is evidence that extragalactic planets, exoplanets farther away in galaxies beyond the local Milky Way galaxy, may exist."
"The nearest exoplanets are located 4.2 light-years (1.3 parsecs) from Earth and orbit Proxima Centauri, the closest star to the Sun."
"The discovery of exoplanets has intensified interest in the search for extraterrestrial life."
"There is special interest in planets that orbit in a star's habitable zone (or sometimes called 'goldilocks zone'), where it is possible for liquid water, a prerequisite for life as we know it, to exist on the surface."
"Rogue planets are those that do not orbit any star."
"The rogue planets in the Milky Way possibly number in the billions or more."
"However, the study of planetary habitability also considers a wide range of other factors in determining the suitability of a planet for hosting life."
"Transit photometry and Doppler spectroscopy have found the most."
"The first possible evidence of an exoplanet was noted in 1917, but was not recognized as such."