Universe Guide

CV Circini

CV Circini Facts

  • CV Circini is a eruptive subgiant star that can be located in the constellation of Circinus. The description is based on the spectral class.
  • CV Circini is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (B1/2IVne) of the star, the star's colour is blue .
  • 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 5260.70 light years away from us. Distance

CV Circini's Alternative Names

HIP74147 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD133738.

CV Circini has alternative name(s) :- , CV Cir.

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

Location of CV Circini

The location of the subgiant 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 CV Circini, the location is 15h 09m 03.32 and -61° 53` 15.2 .

Radial Velocity and Proper Motion of CV Circini

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 -9.93 ± 0.38 milliarcseconds/year towards the north and -6.35 ± 0.47 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 -8.00000 km/s with an error of about 7.40 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 CV Circini

CV Circini Temperature and Colour

Based on the star's spectral type of B1/2IVne , CV Circini's colour and type is blue subgiant star. The star has a B-V Colour Index of 0 which means the star's temperature is about 9,531 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

CV Circini Radius

CV Circini estimated radius has been calculated as being 16.24 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 11,301,707.79.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 22.318573038226154496795948944. 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.

CV Circini Apparent and Absolute Magnitudes

CV Circini has an apparent magnitude of 6.97 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 -3.38 If you used the 2007 Parallax value, you would get an absolute magnitude of -4.07. 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 CV Circini

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 0.85000 which gave the calculated distance to CV Circini as 3837.22 light years away from Earth or 1176.47 parsecs. If you want that in miles, it is about 22,557,578,854,487,611.96, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 0.62000 which put CV Circini at a distance of 5260.70 light years or 1612.90 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 332,682,187.83 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 CV Circini

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 A3807364,793,359,918.72
Speed of Sound (Mach 1)767.2694,598,013,083.00
Concorde (Mach 2)1,534.542,299,003,545.15
New Horizons Probe33,000106,906,451.52
Speed of Light670,616,629.005,260.70

Variable Type of CV Circini

The star is a eruptive Gamma Cassiopeiae 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. CV Circini brightness ranges from a magnitude of 7.027 to a magnitude of 6.904 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 0.1 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.

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Additional CV Circini Facts and Figures

Visual Facts

Primary / Proper / Traditional NameCV Circini
Alternative NamesHD 133738, HIP 74147, CV Cir
Spectral TypeB1/2IVne
Constellation's Main StarNo
Multiple Star SystemNo / Unknown
Star TypeSubgiant Star
GalaxyMilky Way
Absolute Magnitude -3.38 / -4.07
Visual / Apparent Magnitude6.97
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)15h 09m 03.32
Declination (Dec.)-61° 53` 15.2
Galactic Latitude-3.22073743 degrees
Galactic Longitude318.39783784 degrees
1997 Distance from Earth0.85000 Parallax (milliarcseconds)
 3837.22 Light Years
 1176.47 Parsecs
2007 Distance from Earth0.62000 Parallax (milliarcseconds)
 5260.70 Light Years
 1612.90 Parsecs
 332,682,187.83 Astronomical Units
Proper Motion Dec.-9.93000 ± 0.38000 milliarcseconds/year
Proper Motion RA.-6.35000 ± 0.47000 milliarcseconds/year
B-V Index0
Radial Velocity-8.00000 ± 7.40 km/s

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassEruptive
Variable Star TypeGamma Cassiopeiae
Mean Variability Period in Days0.139
Variable Magnitude Range (Brighter - Dimmer)6.904 - 7.027

Estimated Calculated Facts

Radius (x the Sun)22.32
Effective Temperature9,531 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Comments and Questions

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