Your guide to the Solar System and the night sky
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🌎  Observing from: Greenwich, United Kingdom [change]
🌅 Sunrise: 5:52  ☀️ Transit: 12:04  🌅 Sunset: 18:18

θ Boötis (theta Boötis)

θ Boötis is a variable and double main-sequence star in the constellation of Boötes.

θ Boötis visual magnitude is 4.05. Because of its moderate brightness, θ Boötis should be easily visible from locations with dark skyes, while it can be barely visible, or not visible at all, from skyes affected by light pollution.

The table below summarizes the key facts about θ Boötis:

θ Boötis (theta Boötis) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 17°.

Celestial coordinates and finder chart of θ Boötis

θ Boötis is situated north of the celestial equator, as such, it is more easily visible from the northern hemisphere. Celestial coordinates for the J2000 equinox as well as galactic coordinates of θ Boötis are provided in the following table:

14h 25m 11s
+51° 51’ 02”

The simplified sky map below shows the position of θ Boötis in the sky:

Finder chart θ Boötis (theta Boötis) star
Simplified finder chart for θ Boötis (theta Boötis).

Visibility of θ Boötis from your location

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

θ Boötis (theta Boötis) is circumpolar and transits at 02:16 UTC (altitude: 89.6°)

Digitized Sky Survey image of θ Boötis

The image below is a photograph of θ Boötis from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5x0.5 degrees (30x30 arcmins). The proper motion of θ Boötis is -0.236 arcsec per year in Right Ascension and -0.397 arcsec per year in Declination and the associated displacement for the next 1000 years is represented with the red arrow.

Image of θ Boötis (theta Boötis) star
DSS2 image of θ Boötis. The red arrow shows the motion of θ Boötis during the next 1000 years (-3.93 arcmin in Right Ascension and -6.62 arcmin in declination);

Distance of θ Boötis from the Sun and relative movement

θ Boötis is distant 47.50 light years from the Sun and it is moving towards the Sun at the speed of 11 kilometers per second.

14.57 pc
47.50 ly
-11 km/s
-0.236 arcsec/year
-0.397 arcsec/year

Spectral properties of θ Boötis

θ Boötis belongs to spectral class F7 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where θ Boötis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of θ Boötis. Attribution: Richard Powell / CC BY-SA

θ Boötis star system properties

θ Boötis is a visual double star which can be observed only with the help of very large telescopes. The table below shows key information about the θ Boötis double sysyem:

69.5 arcsec

Alternative designations of θ Boötis

θ Boötis
(theta Boötis)
Gl 549 A