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Diphda (Beta Ceti) - HD4128 - HIP3419 - HR188

Diphda (Beta Ceti) is a orange to red giant star that can be located in the constellation of Cetus. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

Beta Ceti is the Bayer Classification for the star. The Id of the star in the Yale Bright Star Catalogue is HR188. HIP3419 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD4128. The Id of the star in the Gould Star Catalogue is 70. Stars in the southern hemisphere are more likely to have a Gould Id than the northern hemisphere. For example, there are no Gould classified stars in Ursa Major. The Gliese ID of the star is Gliese GL31. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Ref : Star Names.

Diphda has alternative name(s), 16 Ceti, Deneb Kaitos , NSV_00272, 16 Cet. In Arabic, it is known as Ad-Difdi'.

Location of Diphda

The location of the star in the galaxy is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the star is compared to the celestial equator and is expressed in degrees. For Diphda, the location is 00h 43m 35.23 and -17d59`12.1 .

Proper Motion of Diphda

All stars like planets orbit round a central spot, in the case of planets, its the central star such as the Sun. In the case of a star, its the galactic centre. The constellations that we see today will be different than they were 50,000 years ago or 50,000 years from now. Proper Motion details the movements of these stars and are measured in milliarcseconds. The star is moving 31.99 ± 0.12 miliarcseconds/year towards the north and 232.55 ± 0.16 miliarcseconds/year east if we saw them in the horizon.

Diphda Luminosity

Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 96.0000000 that I have given is based on the Spectral Types page that I have found on the Internet. You might find a different figure, one that may have been calculated rather than generalised that I have done. The figure is always the amount times the luminosity of the Sun. It is an imprecise figure because of a number of factors including but not limited to whether the star is a variable star and distance.

Physical Properties (Colour, Temperature, Radius) of Diphda

Diphda has a spectral type of K0III. This means the star is a orange to red giant star. The star is 7402.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24142.6107228800000000s. The star has a B-V Colour Index of 1.01 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,830 Kelvin.

Diphda Radius has been calculated as being 15.31 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 10,653,603.12.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 15.38. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is 0.02 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

Diphda Apparent and Absolute Magnitudes

Diphda has an apparent magnitude of 2.04 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of -0.30 If you used the 2007 Parallax value, you would get an absolute magnitude of -0.31. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.

Distance to Diphda

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 34.04 which gave the calculated distance to Diphda as 95.82 light years away from Earth or 29.38 parsecs. It would take a spaceship travelling at the speed of light, 95.82 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

In 2007, Hipparcos data was revised with a new parallax of 33.86 which put Diphda at a distance of 96.33 light years or 29.53 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.

The star's Galacto-Centric Distance is 7,402.00 Parsecs or 24,142.61 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*. Diphda brightness ranges from a magnitude of 2.000 to a magnitude of 2.000 over its variable period. The smaller the magnitude, the brighter the star.

Source of Information

The source of the information if it has a Hip I.D. is from Simbad, the Hipparcos data library based at the University at Strasbourg, France. Hipparcos was a E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated so they could well be wrong. Information regarding Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

Diphda Facts

Alternative Names

Traditional/Proper NameDiphda
Short NameNSV 00272, 16 Cet
Arabic NameAd-Difdi'
English MeaningThe frog
Bayer DesignationBeta Ceti
Alternative Name(s)16 Ceti, Deneb Kaitos
Hipparcos Library I.D.3419
Yale Bright Star Catalogue (HR) Id188
Bonner DurchmusterungBDD-18 115
Gould I.D.70
Gliese ID31
Henry Draper Designation4128

Visual Facts

Star Typegiant star
Absolute Magnitude-0.30 / -0.31
Visual / Apparent Magnitude2.04
Naked Eye VisibleYes - Ref: Wiki
Right Ascension (R.A.)00h 43m 35.23
Declination (Dec.)-17d59`12.1
Galactic Latitude-80.68 degrees
Galactic Longitude111.33 degrees
1997 Distance from Earth34.04 Parallax (milliarcseconds)
 95.82 Light Years
 29.38 Parsecs
2007 Revised Distance from Earth33.86 Parallax (milliarcseconds)
 96.33 Light Years
 29.53 Parsecs
Galacto-Centric Distance24,142.61 Light Years / 7,402.00 Parsecs
Proper Motion Dec.31.99 ± 0.12 milliarcseconds/year
Proper Motion RA.232.55 ± 0.16 milliarcseconds/year
B-V Index1.01
Radial Velocity13.10 ± 0.10 km/s
Iron Abundance0.02 ± 9.99 Fe/H
Spectral TypeK0III
Colour(K) Orange to Red

Variable Star Details

Estimated Facts

Luminosity (x the Sun)96.0000000
Calculated Effective Temperature4,830 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Location of Diphda in Cetus


Diphda (Beta Ceti) Location in Cetus

The map was generated using Night Vision, an awesome free application by Brian Simpson.


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