Universe Guide


61 Cygni - HD201091 - HIP104214

61 Cygni is a orange to red rotating main sequence dwarf star that can be located in the constellation of Cygnus. 61 Cygni is the brightest star in Cygnus 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.

HIP104214 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD201091. The Gliese ID of the star is Gliese GL820A. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Ref : Star Names.

61 Cygni has alternative name(s), 61 Cygni , V1803_Cyg, 61 Cyg.

Location of 61 Cygni

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 61 Cygni, the location is 21h 06m 50.84 and +38d44`29.4 .

Proper Motion of 61 Cygni

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 3,269.20 ± 6.85 miliarcseconds/year towards the north and 4,168.31 ± 6.78 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of 61 Cygni

61 Cygni has a spectral type of K5V. This means the star is a orange to red main sequence dwarf star. The star is 7400.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24136.0874560000000000s. The star has a B-V Colour Index of 1.06 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 4,736 Kelvin.

61 Cygni Radius has been calculated as being 0.44 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 306,542.65.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 0.44. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is -0.19 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.

The star has a companion star which is in orbit close by, it has at least the following companions in close orbit, 61 Cygni B.

61 Cygni Apparent and Absolute Magnitudes

61 Cygni 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 7.49 If you used the 2007 Parallax value, you would get an absolute magnitude of 7.49. 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 61 Cygni

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 287.13 which gave the calculated distance to 61 Cygni as 11.36 light years away from Earth or 3.48 parsecs. It would take a spaceship travelling at the speed of light, 11.36 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 286.82 which put 61 Cygni at a distance of 11.37 light years or 3.49 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.

The star's Galacto-Centric Distance is 7,400.00 Parsecs or 24,136.09 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Variable Type of 61 Cygni

The star is a rotating BY Draconis 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. 61 Cygni brightness ranges from a magnitude of 6.000 to a magnitude of 5.000 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 1.0 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.

61 Cygni Facts

Alternative Names

Traditional/Proper Name61 Cygni
Short NameV1803 Cyg, 61 Cyg
Alternative Name(s)61 Cygni
Hipparcos Library I.D.104214
Bonner DurchmusterungBDD+38 4343
Gliese ID820A
Henry Draper Designation201091

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude7.49 / 7.49
Visual / Apparent Magnitude5.20
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)21h 06m 50.84
Declination (Dec.)+38d44`29.4
Galactic Latitude-5.82 degrees
Galactic Longitude82.31 degrees
1997 Distance from Earth287.13 Parallax (milliarcseconds)
 11.36 Light Years
 3.48 Parsecs
2007 Revised Distance from Earth286.82 Parallax (milliarcseconds)
 11.37 Light Years
 3.49 Parsecs
Galacto-Centric Distance24,136.09 Light Years / 7,400.00 Parsecs
Proper Motion Dec.3269.20 ± 6.85 milliarcseconds/year
Proper Motion RA.4168.31 ± 6.78 milliarcseconds/year
B-V Index1.06
Radial Velocity-65.74 ± 0.09 km/s
Iron Abundance-0.19 ± 9.99 Fe/H
Spectral TypeK5V
Colour(K) Orange to Red

Companions (Multi-Star and Exoplanets) Facts

Companion Stars61 Cygni B

Variable Star Details

Variable Star ClassRotating
Variable Star TypeBY Draconis
Mean Variability Period in Days1.000
Variable Magnitude Range (Brighter - Dimmer)5.000 - 6.000

Estimated Facts

Calculated Effective Temperature4,736 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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