Delta Scuti (δ Sct / δ Scuti) is a triple star system in the constellation Scutum. It is approximately 187 light years from Earth. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... The J2000. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Scutum (Latin for shield) is a small constellation. ... Right ascension (RA; symbol α: Greek letter alpha; celestial longitude) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... The distance between two points is the length of a straight line segment between them. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Henry Draper Catalogue is an astronomy catalogue with astrometric and spectroscopic data about more than 225,000 stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ... Hipparcos (for High Precision Parallax Collecting Satellite) was an astrometry mission of the European Space Agency (ESA) dedicated to the measurement of stellar parallax and the proper motions of stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ... A triple star system consists of three gravitationally bound stars. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Scutum (Latin for shield) is a small constellation. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... Earth is the third planet from the Sun. ...

Delta Scuti is also the prototype of the Delta Scuti type variable stars. The primary component of the star system, properly called Delta Scuti A, is a yellow-white F-type giant. It pulsates regularly with a period of 4.65 hours which results fluctuations in brightness from magnitude +4.60 to magnitude +4.79. It has two companion stars, the +12.2 magnitude Delta Scuti B, which is 15.2 arcseconds from the primary, and the +9.2 magnitude Delta Scuti C, which is 53 arcseconds away. A Delta Scuti variable is a variable star which exhibits variations in its luminosity due to both radial and non-radial pulsations of the stars surface. ... Most stars are of nearly constant luminosity. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... Giant star is a star that has stopped fusing hydrogen in its core. ... A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ...