Universe Guide

Zubeneschamali (Beta Librae, 27 Librae) Star Facts

Zubeneschamali Facts

  • Zubeneschamali is a main sequence star that can be located in the constellation of Libra. The description is based on the spectral class.
  • Zubeneschamali is a main star of the constellation outline.
  • Based on the spectral type (B8V) of the star, the star's colour is blue .
  • Zubeneschamali is the 1st brightest star in Libra based on the Hipparcos 2007 apparent magnitude. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.
  • Zubeneschamali has a radius that is 4.90 times bigger than the Suns. Radius
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 185.11 light years away from us. Distance

Information on Zubeneschamali

Zubeneschamali is a star that creates a lot of discussion. There are a number of people who state this star is green and not any of the uniform star colours such as Blue, Yellow or White. Those who disagree about the colour say it is an optical illusion caused by the its environment. It is not the only star that is believed to be green, the companion star of Antares is also believed to be green but Zubenschamali is the brightest star that is possibly green.

The question over its colour maybe answered when the James Webb telescope goes into operation and takes a close look at the star. Failing that we`ll either have to visit it or wait for another advanced telescope to put up into space to take a look at the star.

Zubeneschamali's Alternative Names

Beta Librae (Bet Lib) 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 HR5685. HIP74785 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD135742.

Zubeneschamali has alternative name(s) :- Lanx Australis, zubenelschemali. In Arabic, it is known as Az-Zuban ash-Shamali.

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 27 Librae. The Flamsteed name can be shortened to 27 Lib.

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 3935.

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

Location of Zubeneschamali

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 Zubeneschamali, the location is 15h 17m 00.47 and -09° 22` 58.3 .

Radial Velocity and Proper Motion of Zubeneschamali

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 -19.65 ± 0.10 milliarcseconds/year towards the north and -98.10 ± 0.16 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 -35.60000 km/s with an error of about 1.80 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 Zubeneschamali

Zubeneschamali Colour and Temperature

Based on the star's spectral type of B8V , Zubeneschamali's colour and type is blue main sequence star. The star's effective temperature is 12,300 Kelvin which is hotter than our own Sun's effective Temperature which is 5,777 Kelvin.

Zubeneschamali 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 390.03 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Zubeneschamali Radius

Zubeneschamali Radius has been calculated as being 4.90 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 3,409,420.00.km. If you need the diameter of the star, you just need to multiple the radius by 2.

Zubeneschamali Mass

The Zubeneschamali's solar mass is 3.50 times that of our star, the Sun. The Sun's Mass is 1,989,100,000,000,000,000,000 billion kg. which to calculate using this website is too large. To give idea of size, the Sun is 99.86% the mass of the solar system.

Zubeneschamali Iron Abundance

Zubeneschamali Iron Abundance is 0.33 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.

Zubeneschamali Apparent and Absolute Magnitudes

Zubeneschamali has an apparent magnitude of 2.61 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 -0.84 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.16. 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 Zubeneschamali

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 20.38000 which gave the calculated distance to Zubeneschamali as 160.04 light years away from Earth or 49.07 parsecs. If you want that in miles, it is about 940,815,204,724,304.94, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 17.62000 which put Zubeneschamali at a distance of 185.11 light years or 56.75 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 11,705,446.19 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 7,357.00 Parsecs or 23,995.84 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 Zubeneschamali

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 A380736168,665,549.18
Speed of Sound (Mach 1)767.269161,791,815.12
Concorde (Mach 2)1,534.5480,895,802.13
New Horizons Probe33,0003,761,752.85
Speed of Light670,616,629.00185.11

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 Zubeneschamali Facts and Figures

Visual Facts

Primary / Proper / Traditional NameZubeneschamali
Alternative NamesBeta Librae, Bet Lib, Lanx Australis, zubenelschemali, Az-Zuban ash-Shamali, HD 135742, HIP 74785, HR 5685, 27 Librae, 27 Lib, BD-08 3935
Spectral TypeB8V
Constellation's Main StarYes
Multiple Star SystemNo / Unknown
Star Type Main Sequence Dwarf Star
GalaxyMilky Way
Absolute Magnitude -0.84 / -1.16
Visual / Apparent Magnitude2.61
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)15h 17m 00.47
Declination (Dec.)-09° 22` 58.3
Galactic Latitude39.23412458 degrees
Galactic Longitude352.02237508 degrees
1997 Distance from Earth20.38000 Parallax (milliarcseconds)
 160.04 Light Years
 49.07 Parsecs
2007 Distance from Earth17.62000 Parallax (milliarcseconds)
 185.11 Light Years
 56.75 Parsecs
 11,705,446.19 Astronomical Units
Galacto-Centric Distance23,995.84 Light Years / 7,357.00 Parsecs
Proper Motion Dec.-19.65000 ± 0.10000 milliarcseconds/year
Proper Motion RA.-98.10000 ± 0.16000 milliarcseconds/year
B-V Index-0.07
Radial Velocity-35.60000 ± 1.80 km/s
Iron Abundance0.3300 ± 9.99 Fe/H
Semi-Major Axis7162.0000000
Stellar Luminosity (Lsun)390.0300000

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Radius (x the Sun)4.90
Effective Temperature10,845 Kelvin
Mass Compared to the Sun3.50

Sources and Links

SIMBAD SourceLink

Location of Zubeneschamali in Libra

Zubeneschamali Location in Libra

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

Libra Main Stars

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