Extrasolar planet in the context of Habitable zone

PSR B1257+12, alternatively designated PSR J1300+1240, is a millisecond pulsar, 2,300 light-years (710 parsecs) from the Sun, in the constellation Virgo, rotating at 160.8 times per second (faster than the blade of a blender). It is also named Lich, after a powerful, fictional undead creature.

The pulsar has a planetary system with three known pulsar planets, named "Draugr" (PSR B1257+12 b or PSR B1257+12 A), "Poltergeist" (PSR B1257+12 c, or PSR B1257+12 B), and "Phobetor" (PSR B1257+12 d, or PSR B1257+12 C). They were both the first extrasolar planets to be discovered and the first pulsar planets to be discovered—B and C in 1992 and A in 1994. A is the lowest-mass planet yet discovered by any observational technique, having somewhat less than twice the mass of Earth's moon.

The study of extraterrestrial atmospheres is an active field of research, both as an aspect of astronomy and to gain insight into Earth's atmosphere. In addition to Earth, many of the other astronomical objects in the Solar System have atmospheres. These include all the giant planets, as well as Mars, Venus and Titan. Several moons and other bodies also have atmospheres, as do comets and the Sun. There is evidence that extrasolar planets can have an atmosphere. Comparisons of these atmospheres to one another and to Earth's atmosphere broaden our basic understanding of atmospheric processes such as the greenhouse effect, aerosol and cloud physics, and atmospheric chemistry and dynamics.

In September 2022, astronomers were reported to have formed a new group, called "Categorizing Atmospheric Technosignatures" (CATS), to list the results of exoplanet atmosphere studies for biosignatures, technosignatures and related.

Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space—what they are, rather than where they are", which is studied in celestial mechanics.

Among the subjects studied are the Sun (solar physics), other stars, galaxies, extrasolar planets, the interstellar medium, and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.

Kepler-37, also known as UGA-1785, is a G-type main-sequence star located in the constellation Lyra 209 light-years (64 parsecs) from Earth. It is host to exoplanets Kepler-37b, Kepler-37c, Kepler-37d and possibly Kepler-37e, all of which orbit very close to it. Kepler-37 has a mass about 80.3 percent of the Sun's and a radius about 77 percent as large. It has a temperature similar to that of the Sun, but a bit cooler at 5,357 K. It has about half the metallicity of the Sun. With an age of roughly 6 billion years, it is slightly older than the Sun, but is still a main-sequence star. Until January 2015, Kepler-37 was the smallest star to be measured via asteroseismology.

Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.As of June 2025, over 1,100 known extrasolar planets (about 19.0% of the total) have been discovered using Doppler spectroscopy.

The Jupiter mass, also called Jovian mass, is the unit of mass equal to the total mass of the planet Jupiter. This value may refer to the mass of the planet alone, or the mass of the entire Jovian system to include the moons of Jupiter. Jupiter is by far the most massive planet in the Solar System. It is approximately 2.5 times as massive as all of the other planets in the Solar System combined.

Jupiter mass is a common unit of mass in astronomy that is used to indicate the masses of other similarly-sized objects, including the outer planets, extrasolar planets, and brown dwarfs, as this unit provides a convenient scale for comparison.

In astronomy, planetary mass is a measure of the mass of a planet-like astronomical object. Within the Solar System, planets are usually measured in the astronomical system of units, where the unit of mass is the solar mass (M_☉), the mass of the Sun. In the study of extrasolar planets, the unit of measure is typically the mass of Jupiter (M_J) for large gas giant planets, and the mass of Earth (M_🜨) for smaller rocky terrestrial planets.

The mass of a planet within the Solar System is an adjusted parameter in the preparation of ephemerides. There are three variations of how planetary mass can be calculated:

A coronagraph is a telescopic attachment designed to block out the direct light from a star or other bright object so that nearby objects – which otherwise would be hidden in the object's bright glare – can be resolved. Most coronagraphs are intended to view the corona of the Sun, but a new class of conceptually similar instruments (called stellar coronagraphs to distinguish them from solar coronagraphs) are being used to find extrasolar planets and circumstellar disks around nearby stars as well as host galaxies in quasars and other similar objects with active galactic nuclei (AGN).

The extraterrestrial UFO hypothesis or extraterrestrial hypothesis (ETH), synonymous with interplanetary aircraft and alien UFO technologies, proposes that some unidentified flying objects (UFOs) are best explained as being physical spacecraft occupied by intelligent extraterrestrial organisms (non-human aliens) from other planets, or probes designed by extraterrestrials.

The scientific community has shown very little support for the ETH, and has largely accepted the explanation that reports of UFOs are the result of people misinterpreting common objects or phenomena, or are the work of hoaxers.

William J. (Bill) Borucki (born 1939) is a space scientist who worked at the NASA Ames Research Center. Upon joining NASA in 1962, Borucki joined the group conducting research on the heat shield for Apollo program spacecraft. He later turned his attention to the optical efficiency of lightning strikes in the atmospheres of planets, investigating the propensity that these lightning strikes could create molecules that would later become the precursors for life. Subsequently, Borucki's attention turned to extrasolar planets and their detection, particularly through the transit method. In light of this work, Borucki was named the principal investigator for NASA's Kepler space telescope mission, launched on March 7, 2009 and dedicated to a transit-based search for habitable planets. In 2013, Borucki was awarded the United States National Academy of Sciences's Henry Draper Medal for his work with Kepler. In 2015 he received the Shaw Prize in Astronomy.

Barnard's Star is a small red dwarf star in the constellation of Ophiuchus. At a distance of 5.96 light-years (1.83 pc) from Earth, it is the fourth-nearest-known individual star to the Sun after the three components of the Alpha Centauri system, and is the closest star in the northern celestial hemisphere. Its stellar mass is about 16% of the Sun's, and it has 19% of the Sun's diameter. Despite its proximity, the star has a dim apparent visual magnitude of +9.5 and is invisible to the unaided eye; it is much brighter in the infrared than in visible light.

Barnard's Star is among the most studied red dwarfs because of its proximity and favorable location for observation near the celestial equator. Historically, research on Barnard's Star has focused on measuring its stellar characteristics, its astrometry, and also refining the limits of possible extrasolar planets. Although Barnard's Star is ancient, it still experiences stellar flare events, one being observed in 1998.

The Optical Gravitational Lensing Experiment (OGLE) is a Polish astronomical project based at the University of Warsaw that runs a long-term variability sky survey (1992–present). The main goals are the detection and classification of variable stars (pulsating and eclipsing), discovery of microlensing events, dwarf novae, and studies of the structure of the Galaxy and the Magellanic Clouds. Since the project began in 1992, it has discovered a multitude of extrasolar planets, together with the first planet discovered using the transit method (OGLE-TR-56b) and gravitational microlensing. The project has been led by professor Andrzej Udalski since its inception.

CoRoT (French: Convection, Rotation et Transits planétaires; English: Convection, Rotation and planetary Transits) was a space telescope mission which operated from 2006 to 2013. The mission's two objectives were to search for extrasolar planets with short orbital periods, particularly those of large terrestrial size, and to perform asteroseismology by measuring solar-like oscillations in stars. The mission was led by the French Space Agency (CNES) in conjunction with the European Space Agency (ESA) and other international partners.

Among the notable discoveries was CoRoT-7b, discovered in 2009 which became the first exoplanet shown to have a rock or metal-dominated composition.

Astrophysics is a science that applies the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space—what they are, rather than where they are", which is studied in celestial mechanics.

Among the subjects studied are the Sun (solar physics), other stars, galaxies, extrasolar planets, the interstellar medium, and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.

51 Pegasi b, officially named Dimidium (/dɪˈmɪdiəm/), is an extrasolar planet approximately 50 light-years (15 parsecs) away in the constellation of Pegasus. It was the first exoplanet to be discovered orbiting a main-sequence star, the Sun-like 51 Pegasi, and marked a breakthrough in astronomical research. It is the prototype for a class of planets called hot Jupiters.

In 2017, traces of water were discovered in the planet's atmosphere. In 2019, the Nobel Prize in Physics was awarded in part for the discovery of 51 Pegasi b.

Michel Gustave Édouard Mayor (French pronunciation: [miʃɛl majɔʁ]; born 12 January 1942) is a Swiss astrophysicist and professor emeritus at the University of Geneva's Department of Astronomy. He formally retired in 2007, but remains active as a researcher at the Observatory of Geneva. He is co-laureate of the 2019 Nobel Prize in Physics along with Jim Peebles and Didier Queloz, and the winner of the 2010 Viktor Ambartsumian International Prize and the 2015 Kyoto Prize.

Together with Didier Queloz in 1995, he discovered 51 Pegasi b, the first extrasolar planet orbiting a sun-like star, 51 Pegasi. For this achievement, they were awarded the 2019 Nobel Prize in Physics "for the discovery of an exoplanet orbiting a solar-type star" resulting in "contributions to our understanding of the evolution of the universe and Earth's place in the cosmos".Related to the discovery, Mayor noted that humans will never migrate to such exoplanets since they are "much, much too far away ... [and would take] hundreds of millions of days using the means we have available today". However, due to discoveries by Mayor, searching for extraterrestrial communications from exoplanets may now be a more practical consideration than thought earlier.