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17 Lyrae - HD178449 - HIP93917

17 Lyrae is a blue to white main sequence dwarf star that can be located in the constellation of Lyra. HIP93917 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD178449. 17 Lyrae has alternative name(s), 17 Lyrae , 17 Lyr.

Location of 17 Lyrae

The location of the star in the galaxy 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 star is compared to the celestial equator and is expressed in degrees. For 17 Lyrae, the location is 19h 07m 25.50 and +32d30`06.0 .

Proper Motion of 17 Lyrae

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 032.36 ± 000.24 towards the north and 122.42 ± 000.31 east if we saw them in the horizon.

17 Lyrae 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 5.0000000 that I have given is based on the Spectral Types page that I have found on the Internet. You might find a different figure, one that may have been calculated rather than generalised that I have done. The figure is always the amount times the luminosity of the Sun. It is an imprecise figure because of a number of factors including but not limited to whether the star is a variable star and distance.

Physical Properties (Colour, Temperature, Radius) of 17 Lyrae

17 Lyrae has a spectral type of F0V. This means the star is a blue to white main sequence dwarf star. The star has a B-V Colour Index of 0.36 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,918 Kelvin.

17 Lyrae has been calculated as 2.40 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,672,651.67.km.

17 Lyrae Apparent and Absolute Magnitudes

17 Lyrae has an apparent magnitude of 5.20 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 2.16 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.11. 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 17 Lyrae

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 24.64 which gave the calculated distance to 17 Lyrae as 132.37 light years away from Earth or 40.58 parsecs. It would take a spaceship travelling at the speed of light, 132.37 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 24.05 which put 17 Lyrae at a distance of 135.62 light years or 41.58 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.

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 Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

17 Lyrae Facts

Alternative Names

Traditional Name17 Lyrae
Short Name17 Lyr
Alternative Name(s)17 Lyrae
Hipparcos Library I.D.93917
Bonner DurchmusterungBD+32 3326
Henry Draper Designation178449

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude2.16 / 2.11
Apparent Magnitude5.20
Right Ascension (R.A.)19h 07m 25.50
Declination (Dec.)+32d30`06.0
1997 Distance from Earth24.64 Parallax (milliarcseconds)
 132.37 Light Years
 40.58 Parsecs
2007 Revised Distance from Earth24.05 Parallax (milliarcseconds)
 135.62 Light Years
 41.58 Parsecs
Proper Motion Dec.32.36 ± 0.24 milliarcseconds/year
Proper Motion RA.122.42 ± 0.31 milliarcseconds/year
B-V Index0.36
Spectral TypeF0V
Colour(F) blue to white

Estimated Facts

Radius (x the Sun)2.40
Luminosity (x the Sun)5.0000000
Calculated Effective Temperature6,918 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Multi-Star System

The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.


Proper Motion mas/yr
H.D. IdB.D. IdStar CodeMagnitudeR.A.Dec.SpectrumColourYear
178449+32 3326.0A5.00000125.0000034.00000F0Yellow/White
B9.100001958
C11.400001933
+32 3325.0D9.20000-38.000000.000001956
E9.3000011.0000015.000001956
F8.9000016.00000-3.000001956
EG10.600001910
H10.600001280.000001115.00000M3Red1935
HI11.400001960
HJ11.400001910
HK12.300001910

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