50 Bootis Star Facts
By : John Whitworth / Updated : Mar 30th, 2026 22:05
Contents
50 Bootis is a main sequence star located in the constellation of Bootes, The Bear Driver. 50 Bootis colour is blue, which means that the star is one of the hottest stars in the Universe, hotter than our star.
50 Boötis temperature range is 10,000 to 30,000 Kelvin. 50 Boötis effective temperature is 10,957 Kelvin which is hotter than the Sun's effective temperature, which is 5,777 Kelvin. Based on a parallax of 12.45, 50 Bootis distance from Earth can be calculated at being 261.98 light years away or 75.76 parsecs.
50 Boötis 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.
Physical Properties
50 Bootis Colour and Spectral Type
50 Boötis spectral type of B9Vn which means its colour and type is blue main sequence 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.
50 Boötis 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. 50 Boötis Luminosity figure of 55.17 comes from the Vizier online catalogue. The star generates more energy than our star.
50 Bootis Surface Gravity
The Surface Gravity of 50 Boötis as measured in CGS (Centimeter-Gram-Second) is 4.013. The gravity has a relationship to its mass and radius. The larger the mass, the larger the gravity. 50 Boötis surface gravity has an uncertainty range of between - and +.
50 Bootis Location
50 Boötis 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 50 Boötis, the location is 15h 21m 48.61 and +32° 56` 01.2 .
Based on the location of Bootes, 50 Boötis can be located in the northern hemisphere of the celestial sky. The celestial hemisphere is equivalent to the hemispheres on Earth. 50 Boötis is north 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.
50 Bootis 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.
50 Boötis apparent magnitude is 5.38, 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, 50 Bootis' absolute magnitude is 0.98. If you use the 2007 parallax value, 50 Bootis' absolute magnitude is 0.86. 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.
50 Boötis 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.
50 Boötis Distance from Earth
50 Boötis distance from Earth is 247.09 light-years away from Earth or 75.76 parsecs. If you want that in miles, it is about 1,452,549,543,459,938.195, 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 13.20000.
In 2007, Hipparcos data was revised with a new parallax of 12.45000, which puts the 50 Boötis distance from Earth as 261.98 light years or 80.32 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, 50 Bootis is roughly 16,567,073.797 Astronomical Units from the Earth/Sun give or take a few.
50 Boötis Galacto-Centric Distance is 7,374 Parsecs or 24,051.285 Light Years. The Galacto-Centric Distance is the distance from the 50 Bootis to the Centre of the Galaxy which is Sagittarius A*.
How long it will take to get to 50 Bootis
The time it takes to travel to 50 Boötis 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 - 43,922,036,116.355
- Car - 2,509,830,635.22
- Airbus A380 - 238,706,718.024
- Mach 1 - 228,978,551.806
- Mach 2 - 129,754,907.286
- New Horizons - 4,826,597.375
- Speed of Light - 261.98
50 Bootis 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. 50 Boötis is moving 13.91 ± 0.17 milliarcseconds/year towards the north and -48.63 ± 0.24 milliarcseconds/year east if we saw them in the horizon.
The radial velocity, the speed at which the 50 Boötis is towards the Sun, is -9.00000 km/s with an error of about 3.50 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.
50 Bootis 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 | 50 Bootis |
| Alternative Names | HD 136849, TYC 2566-1640-1, HIP 75178, HR 5718, 50 Boo, BD +33 2581, 2MASS J15214858-3256012 |
| Spectral Type | B9Vn |
| Star Type | High proper-motion Star |
| Colour | blue |
| Galaxy | Milky Way |
| Constellation | Bootes |
| Main Star | No |
| Absolute Magnitude | if(AbsMag1997.HasValue) { 0.98 } / / 0.86 |
| Visual / Apparent Magnitude | 5.38 |
| Visible From Earth | Yes |
| Right Ascension (R.A.) | 15h 21m 48.61 |
| Declination (Dec.) | +32° 56` 01.2 |
| Galactic Latitude | 57.11620758 ° |
| Galactic Longitude | 52.36232343 ° |
| 1997 Distance from Earth | 13.2 Parallax (milliarcseconds) |
| 247.09 Light Years | |
| 75.76 Parsecs | |
| 2007 Distance from Earth | 12.45 Parallax (milliarcseconds) |
| 261.98 Light Years | |
| 80.32 Parsecs | |
| 16567073.7967916672 Astronomical Units | |
| Galacto-Centric Distance | 24051.28498656 Light Years / 7374 Parsecs |
| Proper Motion Dec. | 13.91 ± 0.17 milliarcseconds/year |
| Proper Motion RA. | -48.63 ± 0.24 milliarcseconds/year |
| B-V Index | -0.05 |
| Radial Velocity | -9 ± 3.5 km/s |
| Eccentricity | 0.0233 |
| Semi-Major Axis | 7480 |
| Luminosity (Lsun) | 55.17 |
| Effective Temp. (Kelvin) | 10957 |
| Surface Gravity (cgs) | 4.013 |
| Source Date | January 2015 |
| SIMBAD Source | Link |
| Source | Simbad, Vizier, Vizier, |
