Universe GuideSearchTwitterComments

Z Aquarii

Z Aquarii Facts

Z Aquarii's Alternative Names

HIP117703 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD223737.

Z Aquarii has alternative name(s) :- Z Aqr, Z Aqr.

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-16 6379.

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

Location of Z Aquarii

The location of the luminous giant 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 Z Aquarii, the location is 23h 52m 14.61 and -15° 51` 16.5 .

Radial Velocity and Proper Motion of Z Aquarii

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 -15.57 ± 1.01 miliarcseconds/year towards the north and 9.98 ± 1.46 miliarcseconds/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 68.90 km/s with an error of about 1.90 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 (Colour, Temperature) of Z Aquarii

Z Aquarii Colour and Temperature

Z Aquarii has a spectral type of M1/M2Ib/II. This means the star is a red luminous giant star. The star has a B-V Colour Index of 1.48 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,056 Kelvin.

Z Aquarii Radius

Radius has been calculated as being 94.35 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 65,648,710.63.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 33.63. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

Z Aquarii Apparent and Absolute Magnitudes

Z Aquarii has an apparent magnitude of 9.05 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 -3.49 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.25. 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 Z Aquarii

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.31 which gave the calculated distance to Z Aquarii as 10521.40 light years away from Earth or 3225.81 parsecs. It would take a spaceship travelling at the speed of light, 10521.40 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 0.87 which put Z Aquarii at a distance of 3749.00 light years or 1149.43 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 237,085,304.21 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.

Variable Type of Z Aquarii

The star is a pulsating Semi-Regular Star w 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. Z Aquarii brightness ranges from a magnitude of 9.755 to a magnitude of 8.241 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 133.1 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.

Hide Explanations
Show GridLines

Additional Z Aquarii Facts and Figures

Visual Facts

Primary / Proper / Traditional NameZ Aquarii
Alternative NamesZ Aqr, HD 223737, HIP 117703, BD-16 6379, Z Aqr
Spectral TypeM1/M2Ib/II
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeLuminous Giant Star
GalaxyMilky Way
Absolute Magnitude -3.49 / -1.25
Visual / Apparent Magnitude9.05
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)23h 52m 14.61
Declination (Dec.)-15° 51` 16.5
Galactic Latitude-72.23 degrees
Galactic Longitude69.30 degrees
1997 Distance from Earth0.31 Parallax (milliarcseconds)
 10521.40 Light Years
 3225.81 Parsecs
2007 Distance from Earth0.87 Parallax (milliarcseconds)
 3749.00 Light Years
 1149.43 Parsecs
 237,085,304.21 Astronomical Units
Proper Motion Dec.-15.57 ± 1.01 milliarcseconds/year
Proper Motion RA.9.98 ± 1.46 milliarcseconds/year
B-V Index1.48
Radial Velocity68.90 ± 1.90 km/s

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeSemi-Regular Star w
Mean Variability Period in Days133.100
Variable Magnitude Range (Brighter - Dimmer)8.241 - 9.755

Estimated Calculated Facts

Radius (x the Sun)33.63
Effective Temperature4,056 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

There's no register feature and no need to give an email address if you don't need to. All messages will be reviewed before being displayed. Comments may be merged or altered slightly such as if an email address is given in the main body of the comment.

This website is using cookies. More info. That's Fine