An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not then recognized as such. The first confirmation of the detection occurred in 1992. A different planet, first detected in 1988, was confirmed in 2003. As of 1 May 2024, there are 5,662 confirmed exoplanets in 4,169 planetary systems, with 896 systems having more than one planet. The James Webb Space Telescope (JWST) is expected to discover more exoplanets, and to give more insight into their traits, such as their composition, environmental conditions, and potential for life.
The Black Eye Galaxy is a relatively isolated spiral galaxy 17 million light-years away in the mildly northern constellation of Coma Berenices. It was discovered by Edward Pigott in March 1779, and independently by Johann Elert Bode in April of the same year, as well as by Charles Messier the next year. A dark band of absorbing dust partially in front of its bright nucleus gave rise to its nicknames of the "Black Eye", "Evil Eye", or "Sleeping Beauty" galaxy. M64 is well known among amateur astronomers due to its form in small telescopes and visibility across inhabited latitudes.
Theta Cygni is a star in the northern constellation of Cygnus. It has an apparent visual magnitude of 4.5, so it can be seen from the northern hemisphere with the naked eye in sufficiently dark skies. Based upon parallax measurements, it is at a distance of about 59.8 light-years from the Earth. It is suspected of hosting an extrasolar planet.
A circumbinary planet is a planet that orbits two stars instead of one. The two stars orbit each other in a binary system, while the planet typically orbits farther from the center of the system than either of the two stars. In contrast, circumstellar planets in a binary system have stable orbits around one of the two stars, closer in than the orbital distance of the other star. Studies in 2013 showed that there is a strong hint that a circumbinary planet and its stars originate from a single disk.
HAT-P-11, also designated GSC 03561-02092 and Kepler-3, is an orange dwarf metal rich star 123 light-years away in the constellation Cygnus. This star is notable for its relatively large rate of proper motion. The apparent magnitude of this star is about 9.6, which means it is not visible to the naked eye but can be seen with a medium-sized amateur telescope on a clear dark night. The age of this star is about 6.5 billion years.
Kepler-5 is a star located in the constellation Cygnus in the field of view of the Kepler Mission, a NASA project aimed at detecting planets in transit of, or passing in front of, their host stars as seen from Earth. One closely-orbiting, Jupiter-like planet, named Kepler-5b, has been detected around Kepler-5. Kepler-5's planet was one of the first five planets to be discovered by the Kepler spacecraft; its discovery was announced on January 4, 2010 at the 215th meeting of the American Astronomical Society after being verified by a variety of observatories. Kepler-5 is larger and more massive than the Sun, but has a similar metallicity, a major factor in planet formation.
Kepler-6 is a G-type star situated in the constellation Cygnus. The star lies within the field of view of the Kepler Mission, which discovered it as part of a NASA-led mission to discover Earth-like planets. The star, which is slightly larger, more metal-rich, slightly cooler, and more massive than the Sun, is orbited by at least one extrasolar planet, a Jupiter-sized planet named Kepler-6b that orbits closely to its star.
Kepler-7 is a star located in the constellation Lyra in the field of view of the Kepler Mission, a NASA operation in search of Earth-like planets. It is home to the fourth of the first five planets that Kepler discovered; this planet, a Jupiter-size gas giant named Kepler-7b, is as light as styrofoam. The star itself is more massive than the Sun, and is nearly twice the Sun's radius. It is also slightly metal-rich, a major factor in the formation of planetary systems. Kepler-7's planet was presented on January 4, 2010 at a meeting of the American Astronomical Society.
Kepler-11, also designated as 2MASS J19482762+4154328, is a Sun-like star slightly larger than the Sun in the constellation Cygnus, located some 2,110 light years from Earth. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission uses to detect planets that may be transiting their stars. Announced on February 2, 2011, the star system is among the most compact and flattest systems yet discovered. It is the first discovered case of a star system with six transiting planets. All discovered planets are larger than Earth, with the larger ones being about Neptune's size.
Kepler-1520 is a K-type main-sequence star located in the constellation Cygnus. The star is particularly important, as measurements taken by the Kepler spacecraft indicate that the variations in the star's light curve cover a range from about 0.2% to 1.3% of the star's light being blocked. This indicates that there may be a rapidly disintegrating planet, a prediction not yet conclusively confirmed, in orbit around the star, losing mass at a rate of 1 Earth mass every billion years. The planet itself is about 0.1 Earth masses, or just twice the mass of Mercury, and is expected to disintegrate in about 100-200 million years. The planet orbits its star in just 15.7 hours, at a distance only two stellar diameters away from the star's surface, and has an estimated effective temperature of about 2255 K. The orbital period of the planet is one of the shortest ever detected in the history of the extrasolar planet search. In 2016, the planet was confirmed as part of a data release by the Kepler spacecraft.
Kepler-138, also known as KOI-314, is a red dwarf located in the constellation Lyra, 219 light years from Earth. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets transiting their stars.
Kepler-444 is a triple star system, estimated to be 11.2 billion years old, approximately 119 light-years (36 pc) away from Earth in the constellation Lyra. On 27 January 2015, the Kepler spacecraft is reported to have confirmed the detection of five sub-Earth-sized rocky exoplanets orbiting the main star. The star is a K-type main sequence star. All of the planets are far too close to their star to harbour life forms.
K2-33 is an extremely young pre-main-sequence star located about 453 light-years (139 pc) away from the Earth in the constellation of Scorpius. It is known to host one planet, a super-Neptune, named K2-33b. It is also notable for its young age.
LHS 6343 is a star system in the northern constellation of Lyra. It appears exceedingly faint with a combined apparent magnitude of 13.435. Based on its stellar properties, the system is thought to be about 119.4 light-years away.
Kepler-160 is a main-sequence star approximately the width of our Galactic arm away in the constellation Lyra, first studied in detail by the Kepler Mission, a NASA-led operation tasked with discovering terrestrial planets. The star, which is very similar to the Sun in mass and radius, has three confirmed planets and one unconfirmed planet orbiting it.
