Peacock / Alpha Pavonis Star Facts (Type, Distance, Magnitude, Age, Colour, Location and more)

Peacock, also known as Alpha Pavonis (Bayer) is a spectroscopic binary star located in the constellation of Pavo, The Peacock. Peacock is a major star and forms part of the constellation.

Based on the spectral type (B2IV), Peacock colour is blue, which means that the star is one of the hottest stars in the Universe, hotter than our star.

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Peacock temperature is in the range of 10,000 to 30,000 Kelvin. Based on the spectral type (B2IV) as we don't have the exact temperature', we can deduce that the surface temperature of Peacock is in the order of 10,000 and 25,000K based on the notes from Harvard University. To put this in context, the temperature of our Sun is about 5,778 Kelvin as said by Google.

Peacock is the brightest star in Pavo and the 44th in the night sky based on the Hipparcos 2007 apparent magnitude. Based on a parallax of 18.24, Peacock distance from Earth can be calculated at being 178.82 light years away or 56.18 parsecs.

Peacock is a naked-eye star, so you don't need a telescope or binoculars when you look up on a clear night. The lower the magnitude, the easier it will be to see it.

Location

The location of the Peacock in the night sky is determined by the right ascension (R.A.) and declination (Dec.). These are equivalent to the Longitude and Latitude on Earth. The Right Ascension (Longitude) is expressed in time (hh:mm:ss) and is how far the star is along Earth's celestial equator. If the R.A. is positive, then it's eastwards and vice versa.

The Declination (Latitude) is how far north or south the object is compared to the celestial equator and is expressed in degrees. If the value is positive, it is north of the celestial equator. For Peacock, the location is 20h 25m 38.85 and -56° 44` 05.6 .

Based on the location of Pavo, Peacock can be located in the southern hemisphere of the celestial sky. The celestial hemisphere is equivalent to the hemispheres on Earth. Peacock is south of the Ecliptic. The Ecliptic is the path that the Earth takes as it orbits the Sun. As the Earth is titled, we therefore have Celestial and Ecliptic hemispheres and they can be different for a star.

Physical Properties

Spectral Type

Peacock spectral type of B2IV which means its colour and type is blue spectroscopic binary star. There is no relationship between colour and size. For example, a red star can be large or small. Small stars are more energy efficient than larger stars and live longer.

Peacock Luminosity

Luminosity is the amount of energy a star pumps out relative to the amount that our star, the Sun, gives out. Our star, the Sun's value is 1. Peacock luminosity figure of 864.38 is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012. The star generates more energy than our star.

Magnitude (Apparent / Absolute / Visible)

A number represents a star’s magnitude, whether apparent/visual or absolute. The smaller the number, the brighter the star is. The Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.

Peacock apparent magnitude is 1.94, which is a measure of the star's brightness as seen from Earth. Apparent Magnitude is also known as Visual Magnitude.

If you use the 1997 parallax value, Peacock' absolute magnitude is -1.81. If you use the 2007 parallax value, Peacock' absolute magnitude is -1.75. Absolute Magnitude is the star's apparent magnitude from 10 parsecs or 32.6 light years. The magnitude assumes nothing is between the object and the viewer, such as dust clouds. To compare different stars' actual brightness, you would best use Absolute rather than Apparent Magnitude.

Peacock is visible from Earth without needing binoculars or a telescope. The lower the Apparent Magnitude of a star or other object is, the easier it is to see in the night sky. An object with a magnitude greater than 6.5 cannot be seen without a telescope or other device.


Radial Velocity and Proper Motion

In simplistic terms, all non-rogue stars, like planets, orbit around a central object, although that is actually not true. Where is the centre of the Solar System. For simplicity it's the central star, such as the Sun. In the case of a star, it's the galactic centre. The constellations 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 is measured in milliarcseconds. Peacock is moving -86.02 ± 0.33 milliarcseconds/year towards the north and 6.9 ± 0.52 milliarcseconds/year east if we saw them in the horizon.

The radial velocity, the speed at which the Peacock is moving away from the Sun, is 2.00000 km/s with an error of about 3.90 km/s . When the value is negative, the star and the Sun are getting closer to one another; likewise, a positive number means that two stars are moving away. It's nothing to fear as the stars are so far apart they won't collide in our lifetime, if ever.

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 an E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated, so they could be wrong. Information regarding Metallicity and/or Mass is from the E.U. Exoplanets. The data was obtained as of 12th Feb 2017.

Peacock Fact Table

The table is scrollable if you can't see everything, just swipe the table to see the hidden information.

Primary NamePeacock
Spectral TypeB2IV
Binary or Multiple StarYes
Star TypeSpectroscopic Binary
Colour blue
GalaxyMilky Way
ConstellationPavo
Main StarYes
Absolute Magnitude -1.81 / -1.75
Visual / Apparent Magnitude1.94
Visible From Earth Yes
Right Ascension (R.A.)20h 25m 38.85
Declination (Dec.)-56° 44` 05.6
Galactic Latitude-35.19309926 °
Galactic Longitude340.90457507 °
1997 Distance from Earth17.80000 Parallax (milliarcseconds)
 183.24 Light Years
 56.18 Parsecs
2007 Distance from Earth18.24000 Parallax (milliarcseconds)
 178.82 Light Years
 54.82 Parsecs
 11,307,357.888 Astronomical Units
Galacto-Centric Distance23,999.099 Light Years / 7,358 Parsecs
Proper Motion Dec.-86.02000 ± 0.33000 milliarcseconds/year
Proper Motion RA.6.90000 ± 0.52000 milliarcseconds/year
B-V Index-0.11
Radial Velocity2.00000 ± 3.9 km/s
Eccentricity0.07980
Semi-Major Axis6862.0000000
Luminosity (Lsun)864.3800000
Brightest in Night Sky44th

Sources and Links


Modified Date24th July 2024
Published DateJan 2015
SIMBAD SourceLink


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