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FK Hydrae

FK Hydrae Facts

FK Hydrae's Alternative Names

HIP41201 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD70938.

FK Hydrae has alternative name(s) :- , FK Hya.

BD number is the number that the star was filed under in the Durchmusterung or Bonner Durchmusterung, a star catalogue that was put together by the Bonn Observatory between 1859 to 1903. The star's BD Number is BD-08 2343.

More details on objects' alternative names can be found at Star Names .

Location of FK Hydrae

The location of the variable star in the night sky 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 object is compared to the celestial equator and is expressed in degrees. For FK Hydrae, the location is 08h 24m 27.87 and -08° 31` 12.9 .

Physical Properties (Colour, Temperature) of FK Hydrae

FK Hydrae has a spectral type of Mb. This means the star is a red variable star. The star has a B-V Colour Index of 1.3 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,386 Kelvin.

FK Hydrae Radius has been calculated as being 19.09 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 13,281,713.56.km. If you need the diameter of the star, you just need to multiple the radius by 2. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

FK Hydrae Apparent and Absolute Magnitudes

FK Hydrae has an apparent magnitude of 7.58 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. Using the supplied Parallax value, you would get an absolute magnitude of -0.36 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 FK Hydrae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 2.58 which gave the calculated distance to FK Hydrae as 1264.20 light years away from Earth or 387.60 parsecs. It would take a spaceship travelling at the speed of light, 1264.20 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

Variable Type of FK Hydrae

The star is a pulsating Slow Irregular variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted. FK Hydrae brightness ranges from a magnitude of 7.469 to a magnitude of 6.854 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.6 days (variability).

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.

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Additional FK Hydrae Facts and Figures

Visual Facts

Primary / Proper / Traditional NameFK Hydrae
Alternative NamesHD 70938, HIP 41201, BD-08 2343, FK Hya
Spectral TypeMb
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeVariable Star
GalaxyMilky Way
Absolute Magnitude -0.36
Visual / Apparent Magnitude7.58
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)08h 24m 27.87
Declination (Dec.)-08° 31` 12.9
Galactic Latitude16.26 degrees
Galactic Longitude231.77 degrees
Distance from Earth2.58 Parallax (milliarcseconds)
 1264.20 Light Years
 387.60 Parsecs
 79,947,681.82 Astronomical Units
B-V Index1.30
Radial Velocity57.10 ± 999.00 km/s

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeSlow Irregular
Mean Variability Period in Days0.559
Variable Magnitude Range (Brighter - Dimmer)6.854 - 7.469

Estimated Calculated Facts

Radius (x the Sun)19.09
Effective Temperature4,386 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

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