Universe Guide

Eta Hydrae (7 Hydrae) Star Facts

Minazal Ath Thani Facts

  • Minazal Ath Thani is a main sequence star that can be located in the constellation of Hydra. The description is based on the spectral class.
  • Minazal Ath Thani is a main star of the constellation outline.
  • Based on the spectral type (B3V...) of the star, the star's colour is blue .
  • The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 586.62 light years away from us. Distance

Minazal Ath Thani's Alternative Names

Eta Hydrae (Eta Hya) is the Bayer Classification for the star. The Bayer Classification was created by Johann Bayer in 1603. The brightest star in the constellation is normally given the Alpha designation, there are exceptions such as Pollux which is Beta Geminorum.

The Id of the star in the Yale Bright Star Catalogue is HR3454. HIP42799 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD74280.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John named the stars in the constellation with a number and its latin name, this star's Flamsteed designation is 7 Hydrae. The Flamsteed name can be shortened to 7 Hya.

The Gould star designation is one that was designed by American astronomer, Benjamin Apthorp Gould. Gould stars are predominantly in the Southern and Equatorial constellations but do appear in northern constellations such as Bootes and Orion. The star has the designation 49 G. Hydrae. There are no stars with a Gould designation in Ursa Major for example.

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+03 2039.

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

Location of Minazal Ath Thani

The location of the main sequence 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 Minazal Ath Thani, the location is 08h 43m 13.49 and +03° 23` 55.2 .

Radial Velocity and Proper Motion of Minazal Ath Thani

Proper Motion

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 -1.08 ± 0.14 milliarcseconds/year towards the north and -19.39 ± 0.24 milliarcseconds/year east if we saw them in the horizon.

Radial Velocity

The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is 16.10000 km/s with an error of about 0.30 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.

Physical Properties of Minazal Ath Thani

Minazal Ath Thani Temperature and Colour

Based on the star's spectral type of B3V... , Minazal Ath Thani's colour and type is blue main sequence star. The star has a B-V Colour Index of -0.19 which means the star's temperature is about 16,152 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

Minazal Ath Thani 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 2,137.52 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Minazal Ath Thani Radius

Minazal Ath Thani estimated radius has been calculated as being 2.36 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,640,399.95.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.9544057131878963573918485475. The figure is derived at by using the formula from SDSS rather than peer reviewed papers. It has been known to produce widely incorrect figures.

Minazal Ath Thani Iron Abundance

Minazal Ath Thani Iron Abundance is 0.01 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context. The value comes from the Hipparcos Extended Catalog.

Minazal Ath Thani Apparent and Absolute Magnitudes

Minazal Ath Thani has an apparent magnitude of 4.30 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 -1.48 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.97. 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 Minazal Ath Thani

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 6.99000 which gave the calculated distance to Minazal Ath Thani as 466.61 light years away from Earth or 143.06 parsecs. If you want that in miles, it is about 2,743,025,385,381,204.26, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 5.56000 which put Minazal Ath Thani at a distance of 586.62 light years or 179.86 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.

Using the 2007 distance, the star is roughly 37,098,529.55 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun. The star's Galacto-Centric Distance is 7,518.00 Parsecs or 24,520.96 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Travel Time to Minazal Ath Thani

The time it will take to travel to this star is dependent on how fast you are going. U.G. has done some calculations as to how long it will take going at differing speeds. A note about the calculations, when I'm talking about years, I'm talking non-leap years only (365 days).

The New Horizons space probe is the fastest probe that we've sent into space at the time of writing. Its primary mission was to visit Pluto which at the time of launch (2006), Pluto was still a planet.

DescriptionSpeed (m.p.h.)Time (years)
Airbus A380736534,506,965.90
Speed of Sound (Mach 1)767.269512,723,864.65
Concorde (Mach 2)1,534.54256,361,598.20
New Horizons Probe33,00011,921,125.06
Speed of Light670,616,629.00586.62

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 Minazal Ath Thani Facts and Figures

Visual Facts

Primary / Proper / Traditional NameMinazal Ath Thani
Alternative NamesEta Hydrae, Eta Hya, HD 74280, HIP 42799, HR 3454, 49 G. Hydrae, 7 Hydrae, 7 Hya, BD+03 2039
Spectral TypeB3V...
Constellation's Main StarYes
Multiple Star SystemNo / Unknown
Star Type Main Sequence Dwarf Star
GalaxyMilky Way
Absolute Magnitude -1.48 / -1.97
Visual / Apparent Magnitude4.30
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)08h 43m 13.49
Declination (Dec.)+03° 23` 55.2
Galactic Latitude26.32048277 degrees
Galactic Longitude223.25104325 degrees
1997 Distance from Earth6.99000 Parallax (milliarcseconds)
 466.61 Light Years
 143.06 Parsecs
2007 Distance from Earth5.56000 Parallax (milliarcseconds)
 586.62 Light Years
 179.86 Parsecs
 37,098,529.55 Astronomical Units
Galacto-Centric Distance24,520.96 Light Years / 7,518.00 Parsecs
Proper Motion Dec.-1.08000 ± 0.14000 milliarcseconds/year
Proper Motion RA.-19.39000 ± 0.24000 milliarcseconds/year
B-V Index-0.19
Radial Velocity16.10000 ± 0.30 km/s
Iron Abundance0.0100 ± 9.99 Fe/H
Semi-Major Axis8056.0000000
Stellar Luminosity (Lsun)2137.5200000

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Radius (x the Sun)2.95
Effective Temperature16,152 Kelvin

Sources and Links

SIMBAD SourceLink

Hydra Main Stars

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