Universe Guide

Deneb Algedi (Delta Capricorni, 49 Capricorni) Star Facts

Deneb Algedi Facts

Deneb Algedi's Alternative Names

Delta Capricorni (Del Cap) is the Bayer Classification for the star. The Bayer Classification was created by Johann Bayer in 1603. The brightest star in the constellation is normally given the Alpha designation, there are exceptions such as Pollux which is Beta Geminorum.

The Id of the star in the Yale Bright Star Catalogue is HR8322. HIP107556 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD207098. The Gliese ID of the star is GL 837. The star was part of the original catalogue devised by German Astronomer Wilheim Gliese of stars located within 20 parsecs of Earth. Star Names

Deneb Algedi has alternative name(s) :- , del Cap. In Arabic, it is known as Dhanab al-Jady.

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 49 Capricorni. The Flamsteed name can be shortened to 49 Cap.

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-16 5943.

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

Location of Deneb Algedi

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 Deneb Algedi, the location is 21h 47m 02.29 and -16° 07` 35.6 .

Radial Velocity and Proper Motion of Deneb Algedi

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 -296.70 ± 0.14 milliarcseconds/year towards the north and 261.70 ± 0.19 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 -3.40 km/s with an error of about 0.80 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.

Deneb Algedi 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 8.49 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Physical Properties (Colour, Temperature) of Deneb Algedi

Deneb Algedi Colour and Temperature

Deneb Algedi has a spectral type of A5mF2 (IV). This means the star is a blue - white subgiant star.

The star's effective temperature is 7,301 Kelvin which is hotter than our own Sun's effective Temperature which is 5,777 Kelvin.

Deneb Algedi Radius

Radius has been calculated as being 1.59 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,104,891.09.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 1.60. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

Deneb Algedi Apparent and Absolute Magnitudes

Deneb Algedi has an apparent magnitude of 2.85 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 2.49 If you used the 2007 Parallax value, you would get an absolute magnitude of 2.48. 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 Deneb Algedi

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 84.58 which gave the calculated distance to Deneb Algedi as 38.56 light years away from Earth or 11.82 parsecs. If you want that in miles, it is 25,858,977,214.

In 2007, Hipparcos data was revised with a new parallax of 84.27 which put Deneb Algedi at a distance of 38.70 light years or 11.87 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 2,448,346.19 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 7,393.00 Parsecs or 24,113.26 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 Deneb Algedi

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 A38073635,262,042.86
Speed of Sound (Mach 1)767.26933,824,986.47
Concorde (Mach 2)1,534.5416,912,471.19
New Horizons Probe33,000786,450.41
Speed of Light670,616,629.0038.70

Variable Type of Deneb Algedi

The star is a eclipsing binary sys Beta Lyrae (Sheliak) 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. Deneb Algedi brightness ranges from a magnitude of 3.070 to a magnitude of 2.920 over its variable period. The smaller the magnitude, the brighter the star. Its variable/pulsating period lasts for 1.0 days (variability).

Meteor Showers Radiating from near Deneb Algedi

The August delta Capricornids Meteor Shower radiants from a point near this star. The meteor shower runs typically between with a peak date of 19th August. The speed of a meteor in the shower is 22 Km/s.

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 Deneb Algedi Facts and Figures

Visual Facts

Primary / Proper / Traditional NameDeneb Algedi
Alternative NamesDelta Capricorni, Del Cap, Dhanab al-Jady, HD 207098, HIP 107556, HR 8322, 49 Capricorni, 49 Cap, BD-16 5943, Gliese 837, del Cap
Spectral TypeA5mF2 (IV)
Constellation's Main StarYes
Multiple Star System Yes
Star TypeSubgiant Star
GalaxyMilky Way
Absolute Magnitude 2.49 / 2.48
Visual / Apparent Magnitude2.85
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)21h 47m 02.29
Declination (Dec.)-16° 07` 35.6
Galactic Latitude-46.01 degrees
Galactic Longitude37.60 degrees
1997 Distance from Earth84.58 Parallax (milliarcseconds)
 38.56 Light Years
 11.82 Parsecs
2007 Distance from Earth84.27 Parallax (milliarcseconds)
 38.70 Light Years
 11.87 Parsecs
 2,448,346.19 Astronomical Units
Galacto-Centric Distance24,113.26 Light Years / 7,393.00 Parsecs
Proper Motion Dec.-296.70 ± 0.14 milliarcseconds/year
Proper Motion RA.261.70 ± 0.19 milliarcseconds/year
B-V Index0.18
Radial Velocity-3.40 ± 0.80 km/s
Semi-Major Axis7164.00
Stellar Luminosity (Lsun)8.49

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Variable Star Details

Variable Star ClassEclipsing binary sys
Variable Star TypeBeta Lyrae (Sheliak)
Mean Variability Period in Days1.023
Variable Magnitude Range (Brighter - Dimmer)2.920 - 3.070

Estimated Calculated Facts

Radius (x the Sun)1.60
Effective Temperature7,889 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
207098-16 5943.0A3.00000261.00000-294.00000A5White

Location of Deneb Algedi in Capricornus

Deneb Algedi Location in Capricornus

The map was generated using Night Vision, an awesome free application by Brian Simpson.

Capricornus Main 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