Universe Guide

FZ Ursae Majoris

FZ Ursae Majoris Facts

  • FZ Ursae Majoris is a eruptive variable star that can be located in the constellation of Ursa Major. The description is based on the spectral class.
  • FZ Ursae Majoris is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (M...) of the star, the star's colour is red .
  • The star can not be seen by the naked eye, you need a telescope to see it.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 2280.86 light years away from us. Distance

FZ Ursae Majoris's Alternative Names

HIP44925 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD77833.

FZ Ursae Majoris has alternative name(s) :- , FZ UMa.

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+69 506.

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

Location of FZ Ursae Majoris

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 FZ Ursae Majoris, the location is 09h 09m 05.07 and +69° 12` 38.8 .

Radial Velocity and Proper Motion of FZ Ursae Majoris

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 -12.15 ± 0.42 milliarcseconds/year towards the north and 7.55 ± 0.64 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 -37.23 km/s with an error of about 0.27 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 FZ Ursae Majoris

FZ Ursae Majoris Temperature and Colour

Based on the star's spectral type of M... , FZ Ursae Majoris's colour and type is red variable star. The star has a B-V Colour Index of 1.5 which means the star's temperature is about 4,014 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

FZ Ursae Majoris Radius

FZ Ursae Majoris estimated radius has been calculated as being 88.67 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 61,697,219.18.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 41.47. 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.

FZ Ursae Majoris Apparent and Absolute Magnitudes

FZ Ursae Majoris has an apparent magnitude of 7.56 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 -3.31 If you used the 2007 Parallax value, you would get an absolute magnitude of -1.66. 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 FZ Ursae Majoris

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.67 which gave the calculated distance to FZ Ursae Majoris as 4868.11 light years away from Earth or 1492.54 parsecs. If you want that in miles, it is about 28,617,794,965,448,863.68, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 1.43 which put FZ Ursae Majoris at a distance of 2280.86 light years or 699.30 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 144,239,973.93 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.

Travel Time to FZ Ursae Majoris

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 A3807362,078,237,288.62
Speed of Sound (Mach 1)767.2691,993,541,566.81
Concorde (Mach 2)1,534.54996,769,484.29
New Horizons Probe33,00046,350,989.22
Speed of Light670,616,629.002,280.86

Variable Type of FZ Ursae Majoris

The star is a eruptive 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. FZ Ursae Majoris brightness ranges from a magnitude of 7.621 to a magnitude of 7.409 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.2 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 FZ Ursae Majoris Facts and Figures

Visual Facts

Primary / Proper / Traditional NameFZ Ursae Majoris
Alternative NamesHD 77833, HIP 44925, BD+69 506, FZ UMa
Spectral TypeM...
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeVariable Star
GalaxyMilky Way
ConstellationUrsa Major
Absolute Magnitude -3.31 / -1.66
Visual / Apparent Magnitude7.56
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)09h 09m 05.07
Declination (Dec.)+69° 12` 38.8
Galactic Latitude37.22 degrees
Galactic Longitude144.51 degrees
1997 Distance from Earth0.67 Parallax (milliarcseconds)
 4868.11 Light Years
 1492.54 Parsecs
2007 Distance from Earth1.43 Parallax (milliarcseconds)
 2280.86 Light Years
 699.30 Parsecs
 144,239,973.93 Astronomical Units
Proper Motion Dec.-12.15 ± 0.42 milliarcseconds/year
Proper Motion RA.7.55 ± 0.64 milliarcseconds/year
B-V Index 1.50
Radial Velocity-37.23 ± 0.27 km/s

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeIrregular
Mean Variability Period in Days0.192
Variable Magnitude Range (Brighter - Dimmer)7.409 - 7.621

Estimated Calculated Facts

Radius (x the Sun)41.47
Effective Temperature4,014 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

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