19 Aquarii Star Facts
By : John Whitworth / Updated : Mar 30th, 2026 22:05
Contents
19 Aquarii is a subgiant star located in the constellation of Aquarius, The Water Carrier. 19 Aquarii colour is yellow - white.
19 Aquarii temperature range is between 6,000 and 7,500 Kelvin. 19 Aquarii effective temperature is 7,656 Kelvin which is hotter than the Sun's effective temperature, which is 5,777 Kelvin. Based on a parallax of 10.89, 19 Aquarii distance from Earth can be calculated at being 299.51 light years away or 84.60 parsecs.
19 Aquarii 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.
The Michigan Spectral Classification for 19 Aquarii is A8 V. The Hipparcos or Simbad spectral class is F0IV, and it is the latter which will be used for descriptions on this site.
Physical Properties
19 Aquarii Colour and Spectral Type
19 Aquarii spectral type of F0IV which means its colour and type is yellow to white subgiant 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.
19 Aquarii 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. 19 Aquarii Luminosity figure of 26.125 comes from the Vizier online catalogue. The star generates more energy than our star.
19 Aquarii Size (Radius)
19 Aquarii radius has been calculated as being 2.76 times bigger than the Sun. The Sun's radius is 695,800km, therefore, the 19 Aquarii radius is an estimated 1,920,408 km.
19 Aquarii Surface Gravity
The Surface Gravity of 19 Aquarii as measured in CGS (Centimeter-Gram-Second) is 3.626. The gravity has a relationship to its mass and radius. The larger the mass, the larger the gravity. 19 Aquarii surface gravity has an uncertainty range of between - and +.
19 Aquarii Location
19 Aquarii location in 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 19 Aquarii, the location is 21h 25m 13.02 and -09° 44` 53.3 .
Based on the location of Aquarius, 19 Aquarii can be located in the equatorial region of the celestial sky. The celestial hemisphere is equivalent to the hemispheres on Earth. Being in the equatorial region, 19 Aquarii can be seen in both terrestrial hemispheres but there is a caveat of depending how far south and north you are. 19 Aquarii is on 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.
19 Aquarii 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.
19 Aquarii apparent magnitude is 5.71, 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, 19 Aquarii' absolute magnitude is 1.07. If you use the 2007 parallax value, 19 Aquarii' absolute magnitude is 0.90. 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.
19 Aquarii is a naked-eye star, that is one 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.
19 Aquarii Distance from Earth
19 Aquarii distance from Earth is 275.94 light-years away from Earth or 84.60 parsecs. If you want that in miles, it is about 1,622,147,885,476,285.343, based on 1 Ly = 5,878,625,373,183.61 miles. The distance is calculated using the parallax from the original Hipparcos data released in 1997 which is 11.82000.
In 2007, Hipparcos data was revised with a new parallax of 10.89000, which puts the 19 Aquarii distance from Earth as 299.51 light years or 91.83 parsecs. It should not be taken as though the star is moving closer or further away from Earth. It is purely that the distance was recalculated.
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. When you use the 2007 distance, 19 Aquarii is roughly 18,941,165.174 Astronomical Units from the Earth/Sun give or take a few.
19 Aquarii Galacto-Centric Distance is 7,348 Parsecs or 23,966.483 Light Years. The Galacto-Centric Distance is the distance from the 19 Aquarii to the Centre of the Galaxy which is Sagittarius A*.
How long it will take to get to 19 Aquarii
The time it takes to travel to 19 Aquarii depends on how fast you are going. U.G. has done some calculations as to how long it will take to go at differing speeds. A note about the calculations, when I'm talking about years, I'm talking about non-leap years only (365 days).
The New Horizons space probe is the fastest one 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.
Mach 1 is the speed of sound; Mach 2 is twice the speed. |Before retiring, Concorde was the fastest commercial aeroplane and the only passenger jet that could do Mach 2.
For some small screens, you may need to swipe the table to see the information. If you need an explanation, hover over the bold text. At methods are assuming you have unlimited fuel and travel at a constant speed.
- Walking - 50,214,096,637.948
- Car - 2,869,376,950.74
- Airbus A380 - 272,902,699.119
- Mach 1 - 261,780,922.404
- Mach 2 - 148,342,973.82
- New Horizons - 5,518,032.598
- Speed of Light - 299.51
19 Aquarii 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. 19 Aquarii is moving -169.81 ± 0.39 milliarcseconds/year towards the north and 16.42 ± 0.63 milliarcseconds/year east if we saw them in the horizon.
The radial velocity, the speed at which the 19 Aquarii is towards the Sun, is -20.60000 km/s with an error of about 1.80 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.
19 Aquarii Facts
Any red fact description is not peer reviewed; it is estimated using other pieces of facts, e.g. temperature if in red is based on the colour of the star.
| Primary Name | 19 Aquarii |
| Alternative Names | HD 203875, EPIC 251163665, TYC 5777-1229-1, HIP 105761, HR 8195, 68 G. Aquarii, 19 Aqr, BD -10 5668, 2MASS J21251302-944548 |
| Spectral Type | F0IV |
| Star Type | High proper-motion Star |
| Colour | yellow to white |
| Galaxy | Milky Way |
| Constellation | Aquarius |
| Main Star | No |
| Absolute Magnitude | if(AbsMag1997.HasValue) { 1.07 } / / 0.9 |
| Visual / Apparent Magnitude | 5.71 |
| Visible From Earth | Yes |
| Right Ascension (R.A.) | 21h 25m 13.02 |
| Declination (Dec.) | -09° 44` 53.3 |
| Galactic Latitude | -38.5044346 ° |
| Galactic Longitude | 42.39990332 ° |
| 1997 Distance from Earth | 11.82 Parallax (milliarcseconds) |
| 275.94 Light Years | |
| 84.6 Parsecs | |
| 2007 Distance from Earth | 10.89 Parallax (milliarcseconds) |
| 299.51 Light Years | |
| 91.83 Parsecs | |
| 18941165.1737970468 Astronomical Units | |
| Galacto-Centric Distance | 23966.48251712 Light Years / 7348 Parsecs |
| Proper Motion Dec. | -169.81 ± 0.39 milliarcseconds/year |
| Proper Motion RA. | 16.42 ± 0.63 milliarcseconds/year |
| B-V Index | 0.2 |
| Radial Velocity | -20.6 ± 1.8 km/s |
| Eccentricity | 0.4812 |
| Semi-Major Axis | 4410 |
| Luminosity (Lsun) | 26.125 |
| Effective Temp. (Kelvin) | 7656 |
| Surface Gravity (cgs) | 3.626 |
| Radius | 2.76 |
| Source Date | January 2015 |
| SIMBAD Source | Link |
| EPIC Source | Epic Search |
| Source | Simbad, Vizier, Vizier, |
