Universe Guide

40 Draconis

40 Draconis Facts

  • 40 Draconis is a main sequence star that can be located in the constellation of Draco. The description is based on the spectral class.
  • 40 Draconis is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (K2Vvar) of the star, the star's colour is orange to red .
  • The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.
  • The star has an estimated age of 3.40 Billion of Years but could be as young as 2.80 to 4.10 according to Hipparcos.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 236.87 light years away from us. Distance

40 Draconis's Alternative Names

The Id of the star in the Yale Bright Star Catalogue is HR6809. HIP88127 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD166865.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John named the stars in the constellation with a number and its latin name, this star's Flamsteed designation is 40 Draconis. The Flamsteed name can be shortened to 40 Dra.

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+79 570.

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

Location of 40 Draconis

The location of the main sequence 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 40 Draconis, the location is 18h 00m 03.37 and +80° 00` 01.9 .

Radial Velocity and Proper Motion of 40 Draconis

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 120.37 ± 6.91 milliarcseconds/year towards the north and 47.06 ± 6.19 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 5.76000 km/s with an error of about 0.07 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 40 Draconis

40 Draconis Colour and Temperature

Based on the star's spectral type of K2Vvar , 40 Draconis's colour and type is orange to red main sequence star. The star has a B-V Colour Index of 0.52 which means the star's temperature is about 6,202 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

40 Draconis Radius

40 Draconis estimated radius has been calculated as being 2.46 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,715,137.64.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 3.5303861481958048258155172486. 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.

40 Draconis Iron Abundance

40 Draconis Iron Abundance is -0.05 with an error value of 0.08 Fe/H with the Sun has a value of 1 to put it into context. The value comes from the Hipparcos Extended Catalog.

40 Draconis Estimated Age

The stars age according to Hipparcos data files put the star at an age of about 3.40 Billion years old but could be between 2.80 and 4.10 Billion years old. In comparison, the Sun's age is about 4.6 Billion Years Old.

40 Draconis Apparent and Absolute Magnitudes

40 Draconis has an apparent magnitude of 6.11 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 2.58 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.80. 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 40 Draconis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 19.64000 which gave the calculated distance to 40 Draconis as 166.07 light years away from Earth or 50.92 parsecs. If you want that in miles, it is about 976,263,315,724,602.11, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 13.77000 which put 40 Draconis at a distance of 236.87 light years or 72.62 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 14,978,845.86 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. The star's Galacto-Centric Distance is 7,416.00 Parsecs or 24,188.27 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

Travel Time to 40 Draconis

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 A380736215,827,392.54
Speed of Sound (Mach 1)767.269207,031,641.98
Concorde (Mach 2)1,534.54103,515,686.08
New Horizons Probe33,0004,813,604.88
Speed of Light670,616,629.00236.87

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 40 Draconis Facts and Figures

Visual Facts

Primary / Proper / Traditional Name40 Draconis
Alternative NamesHD 166865, HIP 88127, HR 6809, 40 Dra, BD+79 570
Spectral TypeK2Vvar
Constellation's Main StarNo
Multiple Star SystemYes
Star Type Main Sequence Dwarf Star
ColourOrange to Red
GalaxyMilky Way
Age3.40 Billion Years Old
Age Range2.80 - 4.10 Billion Years Old
Absolute Magnitude 2.58 / 1.80
Visual / Apparent Magnitude6.11
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)18h 00m 03.37
Declination (Dec.)+80° 00` 01.9
Galactic Latitude28.90861582 degrees
Galactic Longitude111.78113137 degrees
1997 Distance from Earth19.64000 Parallax (milliarcseconds)
 166.07 Light Years
 50.92 Parsecs
2007 Distance from Earth13.77000 Parallax (milliarcseconds)
 236.87 Light Years
 72.62 Parsecs
 14,978,845.86 Astronomical Units
Galacto-Centric Distance24,188.27 Light Years / 7,416.00 Parsecs
Proper Motion Dec.120.37000 ± 6.91000 milliarcseconds/year
Proper Motion RA.47.06000 ± 6.19000 milliarcseconds/year
B-V Index0.52
Radial Velocity5.76000 ± 0.07 km/s
Iron Abundance-0.0500 ± 0.08 Fe/H
Semi-Major Axis8690.0000000

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Radius (x the Sun)3.53
Effective Temperature6,202 Kelvin

Sources and Links

SIMBAD SourceLink

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
166865+79 570.0B6.2000046.00000127.00000F5Yellow/White1984
+79 574.0C9.20000-15.0000021.00000G5Yellow1984

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.

You can decline to give a name which if that is the case, the comment will be attributed to a random star. A name is preferred even if its a random made up one by yourself.

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