Alpha Hydrae

Alphard is the α star in the constellation of Hydra.
Observation data Epoch J2000
Constellation	Hydra
Right ascension	09h 27m 35.2s
Declination	-08° 39′ 31″
Apparent magnitude (V)	+1.98
Characteristics
Spectral type	K3 II-III
B-V color index	1.44
U-B color index	1.72
Variable type	?
Astrometry
Radial velocity (Rv)	-4 km/s
Proper motion (μ)	RA: -14.49 mas/yr Dec.: 33.25 mas/yr
Parallax (π)	18.4 ± 0.78 mas
Distance	177 ± 8 ly (54 ± 2 pc)
Absolute magnitude (MV)	−1.70
Details
Mass	? M☉
Radius	34.5 R☉
Luminosity	400 L☉
Temperature	4,400 K
Metallicity	?
Rotation	<17 km/s.
Age	? years
Other designations
Alphard, Alfard, Alphart, Kalbelaphard, Cor Hydrae, 30 Hydrae, HR 3748, BD -08°2680, HD 81797, SAO 136871, FK5 354, HIP 46390.

Alphard (α Hya / α Hydrae / Alpha Hydrae) is the brightest star in the constellation Hydra. This is a celestial map of the constellation Hydra. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... This article or section does not cite its references or sources. ... Baron Strucker, retconned founder of HYDRA, wearing the HYDRA logo on his chest. ... Right ascension (RA; symbol α: Greek letter alpha) 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. ... // Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ... 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, color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... In astronomy, color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... Most stars are of almost constant luminosity. ... This article does not cite its references or sources. ... Radial velocity is the velocity of an object in the direction of the line of sight. ... kilometre per second is an SI derived unit of both speed (scalar) and velocity (vector), signified by the symbol km/s or km s-1. ... The proper motion of a star is the motion of the position of the star in the sky (the change in direction in which we see it, as opposed to the radial velocity) after eliminating the improper motions of the stars, which affect their measured coordinates but are not real... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... This article or section does not cite its references or sources. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... Distance is a numerical description of how far apart things lie. ... A light-year or lightyear, symbol ly, is the distance light travels in vacuum in one Julian year. ... Stellar parallax motion The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standard luminosity distance away from us (in the absence of interstellar extinction!). It allows the overall brightnesses of objects to be compared without regard to distance. ... Unsolved problems in physics: What causes anything to have mass? Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... In classical geometry, a radius of a circle or sphere is any line segment from its center to its boundary. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... Luminosity has different meanings in several different fields of science. ... The solar luminosity, , is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... [[Image:Translational motion. ... The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ... In astronomy, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium. ... A sphere rotating around its axis. ... The Pleiades, an open cluster of stars in the constellation of Taurus. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... In astronomy, many stars are referred to simply by catalogue numbers. ... 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. ... The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory (HCO) to form the Harvard-Smithsonian Center for Astrophysics (CfA). ... In astronomy, many stars are referred to simply by catalogue numbers. ... Alpha (uppercase Α, lowercase α) is the first letter of the Greek alphabet. ... The Pleiades, an open cluster of stars in the constellation of Taurus. ... This article or section does not cite its references or sources. ... Hydra (IPA: ) is the largest of the 88 modern constellations, and was also one of the 48 constellations listed by Ptolemy. ...

Alphard is an orange giant star. The name Alphard is from the Arabic Al Fard, "the solitary one." The Arabic language ( ), or simply Arabic ( ), is the largest member of the Semitic branch of the Afro-Asiatic language family (classification: South Central Semitic) and is closely related to Hebrew, Amharic and Aramaic. ...