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19 Leonis - HD84722 - HIP48029

19 Leonis is a blue main sequence dwarf star that can be located in the constellation of Leo. The star can be seen with the naked eye, that is, you don't need a telescope/binoculars to see it.

HIP48029 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD84722.

19 Leonis has alternative name(s), 19 Leonis , 19 Leo.

Location of 19 Leonis

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 19 Leonis, the location is 09h 47m 25.99 and +11d34`05.4 .

Proper Motion of 19 Leonis

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 -4.72 ± 0.21 miliarcseconds/year towards the north and -50.52 ± 0.50 miliarcseconds/year east if we saw them in the horizon.

19 Leonis 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 9.0000000 that I have given is based on the Spectral Types page that I have found on the Internet. You might find a different figure, one that may have been calculated rather than generalised that I have done. The figure is always the amount times the luminosity of the Sun. It is an imprecise figure because of a number of factors including but not limited to whether the star is a variable star and distance.

Physical Properties (Colour, Temperature, Radius) of 19 Leonis

19 Leonis has a spectral type of A7Vn. This means the star is a blue main sequence dwarf star. The star is 7444.00000000 Parsecs from the Galactic Centre or terms of Light Years is 24279.5993273600000000s. The star has a B-V Colour Index of 0.25 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 7,483 Kelvin.

19 Leonis Radius has been calculated as being 2.57 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,791,512.92.km. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.43. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

19 Leonis Apparent and Absolute Magnitudes

19 Leonis has an apparent magnitude of 6.44 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 1.67 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 19 Leonis

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 11.14 which gave the calculated distance to 19 Leonis as 292.79 light years away from Earth or 89.77 parsecs. It would take a spaceship travelling at the speed of light, 292.79 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 11.81 which put 19 Leonis at a distance of 276.18 light years or 84.67 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.

The star's Galacto-Centric Distance is 7,444.00 Parsecs or 24,279.60 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.

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.

19 Leonis Facts

Alternative Names

Traditional/Proper Name19 Leonis
Short Name19 Leo
Alternative Name(s)19 Leonis
Hipparcos Library I.D.48029
Bonner DurchmusterungBDD+12 2095
Henry Draper Designation84722

Visual Facts

Star Typemain sequence dwarf star
Absolute Magnitude1.67 / 1.80
Visual / Apparent Magnitude6.44
Naked Eye VisibleYes - Ref: Wiki
Right Ascension (R.A.)09h 47m 25.99
Declination (Dec.)+11d34`05.4
Galactic Latitude44.20 degrees
Galactic Longitude223.53 degrees
1997 Distance from Earth11.14 Parallax (milliarcseconds)
 292.79 Light Years
 89.77 Parsecs
2007 Revised Distance from Earth11.81 Parallax (milliarcseconds)
 276.18 Light Years
 84.67 Parsecs
Galacto-Centric Distance24,279.60 Light Years / 7,444.00 Parsecs
Proper Motion Dec.-4.72 ± 0.21 milliarcseconds/year
Proper Motion RA.-50.52 ± 0.50 milliarcseconds/year
B-V Index0.25
Radial Velocity-3.70 ± 1.78 km/s
Spectral TypeA7Vn
Colour(A) blue

Estimated Facts

Luminosity (x the Sun)9.0000000
Calculated Effective Temperature7,483 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

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
84722+12 2095.0A6.40000-64.000000.00000A7White
B1980

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UGWednesday, 5th April 2017 10:04:58 PM
Nilson, I did some research and 19 Leonis is a Double or Multiple star so SkySafari is correct. If you copy the address at the bottom of this comment into a browser, it'll take you to Simbad, a large star repository used by astronomers world wide. Most commercial software such as SkySafari will be correct. The only time you ever really need to query something is if its on Wikipedia because anyone can edit it. Skysafari will have their reputation on the line if its wrong. The figures in Red are calculated and therefore most likely wrong which is why I state that. When I get some free time, I'll update the information about double and multiple star systems for stars in the database. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=19+Leonis&submit=SIMBAD+search
Nilson BazanaTuesday, 4th April 2017 2:42:52 AM
High nice job on getting so much detail for such a overlooked star. Just one thing though: my copy of the SkySafari mobile app says it is a double star. Does that actually hold any true to it? What do you say? Cheers,