Universe Guide

Eta1 Fornacis

Eta1 Fornacis Facts

  • Eta1 Fornacis is a giant star that can be located in the constellation of Fornax. The description is based on the spectral class.
  • Eta1 Fornacis is not part of the constellation outline but is within the borders of the constellation.
  • Based on the spectral type (K0/K1III) of the star, the star's colour is orange to red .
  • The star can not be seen by the naked eye, you need a telescope to see it.
  • Using the most recent figures given by the 2007 Hipparcos data, the star is 497.96 light years away from us. Distance

Eta1 Fornacis's Alternative Names

Eta1 Fornacis (Eta01 For) 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 HR835. HIP13040 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD17528.

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

Location of Eta1 Fornacis

The location of the giant 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 Eta1 Fornacis, the location is 02h 47m 33.78 and -35° 33` 01.9 .

Radial Velocity and Proper Motion of Eta1 Fornacis

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 -35.06 ± 0.30 milliarcseconds/year towards the north and -41.32 ± 0.41 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 3.40000 km/s with an error of about 0.40 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 Eta1 Fornacis

Eta1 Fornacis Temperature and Colour

Based on the star's spectral type of K0/K1III , Eta1 Fornacis's colour and type is orange to red giant star. The star has a B-V Colour Index of 0.96 which means the star's temperature is about 4,927 Kelvin. The temperature was calculated using information from Morgans @ Uni.edu.

Eta1 Fornacis 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 67.34 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Eta1 Fornacis Radius

Eta1 Fornacis estimated radius has been calculated as being 12.13 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 8,437,650.41.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 9.766354603903788464298851872. 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.

Eta1 Fornacis Apparent and Absolute Magnitudes

Eta1 Fornacis has an apparent magnitude of 6.51 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 0.12 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.59. 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 Eta1 Fornacis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 5.27000 which gave the calculated distance to Eta1 Fornacis as 618.91 light years away from Earth or 189.75 parsecs. If you want that in miles, it is about 3,638,340,029,717,068.07, based on 1 Ly = 5,878,625,373,183.61 miles.

In 2007, Hipparcos data was revised with a new parallax of 6.55000 which put Eta1 Fornacis at a distance of 497.96 light years or 152.67 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 31,490,228.54 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 7,436.00 Parsecs or 24,253.51 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 Eta1 Fornacis

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 A380736453,723,174.70
Speed of Sound (Mach 1)767.269435,232,306.50
Concorde (Mach 2)1,534.54217,615,869.63
New Horizons Probe33,00010,119,401.71
Speed of Light670,616,629.00497.96

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.

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Additional Eta1 Fornacis Facts and Figures

Visual Facts

Primary / Proper / Traditional NameEta1 Fornacis
Alternative NamesEta01 For, HD 17528, HIP 13040, HR 835
Spectral TypeK0/K1III
Constellation's Main StarNo
Multiple Star SystemYes
Star TypeGiant Star
ColourOrange to Red
GalaxyMilky Way
Absolute Magnitude 0.12 / 0.59
Visual / Apparent Magnitude6.51
Naked Eye VisibleRequires a 7x50 Binoculars - Magnitudes
Right Ascension (R.A.)02h 47m 33.78
Declination (Dec.)-35° 33` 01.9
Galactic Latitude-63.92719045 degrees
Galactic Longitude238.99155054 degrees
1997 Distance from Earth5.27000 Parallax (milliarcseconds)
 618.91 Light Years
 189.75 Parsecs
2007 Distance from Earth6.55000 Parallax (milliarcseconds)
 497.96 Light Years
 152.67 Parsecs
 31,490,228.54 Astronomical Units
Galacto-Centric Distance24,253.51 Light Years / 7,436.00 Parsecs
Proper Motion Dec.-35.06000 ± 0.30000 milliarcseconds/year
Proper Motion RA.-41.32000 ± 0.41000 milliarcseconds/year
B-V Index0.96
Radial Velocity3.40000 ± 0.40 km/s
Semi-Major Axis9149.0000000
Stellar Luminosity (Lsun)67.3400000
Associated / Clustered StarsEta3 Fornacis

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Radius (x the Sun)9.77
Effective Temperature4,927 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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