θ Ophiuchi (theta Ophiuchi)
θ Ophiuchi is a variable and double sub-giant star in the constellation of Ophiuchus.
θ Ophiuchi visual magnitude is 3.27. Because of its moderate brightness, θ Ophiuchi 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 Ophiuchi:
Celestial coordinates and finder chart of θ Ophiuchi
θ Ophiuchi is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of θ Ophiuchi are provided in the following table:
The simplified sky map below shows the position of θ Ophiuchi in the sky:
Visibility of θ Ophiuchi from your location
Today's θ Ophiuchi (theta Ophiuchi) rise, transit and set times from Greenwich, United Kingdom are the following (all times relative to the local timezone Europe/London):
Digitized Sky Survey image of θ Ophiuchi
The image below is a photograph of θ Ophiuchi 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 Ophiuchi is -0.004 arcsec per year in Right Ascension and -0.02 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.
Distance of θ Ophiuchi from the Sun and relative movement
θ Ophiuchi is distant 563.04 light years from the Sun and it is moving towards the Sun at the speed of 2 kilometers per second.
Spectral properties of θ Ophiuchi
θ Ophiuchi belongs to spectral class B2 and has a luminosity class of IV corresponding to a sub-giant star.
The red dot in the diagram below shows where θ Ophiuchi is situated in the Hertzsprung–Russell diagram.
θ Ophiuchi star system properties
θ Ophiuchi 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 Ophiuchi double sysyem: