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HD 21447 is a probable
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 ...
system located in the constellation
Camelopardalis Camelopardalis is a large but faint constellation of the northern sky representing a giraffe. The constellation was introduced in 1612 or 1613 by Petrus Plancius. Some older astronomy books give Camelopardalus or Camelopardus as alternative for ...
. The star is also known as HR 1046. It can be viewed with the naked eye, having an apparent visual magnitude of 5.09. Based upon an annual parallax shift of , it is located some 199 
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. It is a candidate for membership in the Ursa Major Moving Group. The primary component is
A-type main-sequence star An A-type main-sequence star (A V) or A dwarf star is a main-sequence (hydrogen-burning) star of spectral type A and luminosity class V (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between 1 ...
with a
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 A1 Va. It is around 146 million years old and is spinning with a
projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulge ...
of 182 km/s. The star has an estimated 2.32 times the
mass of the Sun The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...
and about 1.9 times the Sun's radius. It is radiating around 32 times the Sun's luminosity from its
photosphere The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...
at an
effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...
of 10,049 K. The companion is visual magnitude 9.4 star at an
angular separation Angular distance \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer. Angular distance appears in mathematics (in pa ...
of .


References


External links

*http://www.alcyone.de/cgi-bin/search.pl?object=HR1046 *http://server3.wikisky.org/starview?object_type=1&object_id=1996 {{DEFAULTSORT:HD 21447 A-type main-sequence stars Camelopardalis Durchmusterung objects 021447 016292
1046 Year 1046 ( MXLVI) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events By place Europe * Autumn – King Henry III (the Black) travels to Italy to secure the imposition of G ...