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Delta Delphini, Latinized from δ Delphini, is a 
This is a double-lined
binary star
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...
in the northern constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
of Delphinus
Delphinus (Pronounced or ) is a small constellation in the Northern Celestial Hemisphere, close to the celestial equator. Its name is the Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-Europea ...
. It is visible to the naked eye with an apparent visual magnitude of 4.43. Based upon an annual parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...
shift of 14.61 mas
Mas, Más or MAS may refer to:
Film and TV
* Más y Menos, fictional superhero characters, from the Teen Titans animated television series
* Más (Breaking Bad), "Más" (''Breaking Bad''), a season three episode of ''Breaking Bad''
Songs
* Más ( ...
as seen from the Earth, the system is located about 223 light year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
s from the Sun.
This is a double-lined spectroscopic binary
A binary star is a system of two star, stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separa ...
system with an orbital period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...
of 40.58 days. The two components are nearly identical chemically peculiar stars, having a combined stellar classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...
of kA7hF1VmF1pSrEuCr:. This notation indicates the calcium K line matches an A7 star, the hydrogen lines
The emission spectrum of atomic hydrogen has been divided into a number of spectral series, with wavelengths given by the Rydberg formula. These observed spectral lines are due to the electron making transitions between two energy levels in an ...
an F1 star, and the metal lines an F1 star, with particularly strong lines of strontium, europium, and chromium. Each of the stars is a Delta Scuti variable, with the system having a dominant period of 0.1568 days and an amplitude
The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of amplit ...
of 0.0700 in magnitude. Delta Delphini forms the prototype of a class of metal
A metal (from Greek μÎταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...
- lined δ Scuti subgiant or giant stars.
References
External links
* {{DEFAULTSORT:Delta Delphini A-type main-sequence stars F-type main-sequence stars Delta Scuti variables Am stars Spectroscopic binaries Delphinus (constellation) Delphini, Delta Delphini, 11 197461 102281 7928 Durchmusterung objects