θ1 Orionis (theta1 Orionis)

Altitude: 1.0° Azimuth: 100.0° Direction: East

θ1 Orionis is a variable and multiple hypergiant star in the constellation of Orion.

θ1 Orionis visual magnitude is 6.7. Because of its reltive faintness, θ1 Orionis should be visible only from locations with dark skyes, while it is not visible at all from skyes affected by light pollution.

The table below summarizes the key facts about θ1 Orionis:

Color of θ1 Orionis ⬤

Magnitude of θ1 Orionis 6.7

Class Hypergiant

VISIBILITY RIGHT NOW

θ1 Orionis (theta1 Orionis) is above the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: 1.0°
Azimuth: 100.0°
Direction: East

Celestial coordinates and finder chart of θ1 Orionis

θ1 Orionis 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 θ1 Orionis are provided in the following table:

Right Ascension J2000 05h 35m 17s

Declination J2000 -05° 23’ 16”

Galactic Longitude 209.01°

Galactic Latitude -19.38°

Constellation Orion

The simplified sky map below shows the position of θ1 Orionis in the sky:

Finder chart θ1 Orionis (theta1 Orionis) star

Simplified finder chart for θ1 Orionis (theta1 Orionis).

Visibility of θ1 Orionis from your location

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

Today's θ1 Orionis (theta1 Orionis) rise, transit and set times from Greenwich, United Kingdom edit_location_alt are the following (all times relative to the local timezone Europe/London):

Azimuth: 95.4° RISE 8:13

Max altitude: 33.1° TRANSIT 13:44

Azimuth: 264.6° SET 19:15

RIGHT NOW θ1 Orionis (theta1 Orionis) is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of θ1 Orionis

The image below is a photograph of θ1 Orionis 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 θ1 Orionis is 0.005 arcsec per year in Right Ascension and 0.002 arcsec per year in Declination and the associated displacement for the next 100000 years is represented with the red arrow.

Image of θ1 Orionis (theta1 Orionis) star

DSS2 image of θ1 Orionis. The red arrow shows the motion of θ1 Orionis during the next 100000 years (8.33 arcmin in Right Ascension and 3.33 arcmin in declination);

Distance of θ1 Orionis from the Sun and relative movement

θ1 Orionis is distant 32,600,000.00 light years from the Sun and it is moving far from the Sun at the speed of 31 kilometers per second.

Distance (parsec) 10,000,000.00 pc

Distance (light year) 32,600,000.00 ly

Heliocentric radial velocity 31 km/s

Proper Motion RA 0.005 arcsec/year

Proper Motion Dec 0.002 arcsec/year

Spectral properties of θ1 Orionis

θ1 Orionis belongs to spectral class B0 and has a luminosity class of V corresponding to a hypergiant star.

Absolute magnitude -23.30

Spectral Type B0V

Color Index (B-V) 0.09

Temperature of θ1 Orionis 9125K

The red dot in the diagram below shows where θ1 Orionis is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of θ1 Orionis. Attribution: Richard Powell / CC BY-SA

θ1 Orionis star system properties

θ1 Orionis is a visual double star which can be observed with binoculars or small telescopes. The table below shows key information about the θ1 Orionis double sysyem:

Main star magnitude 6.7

Secondary star magnitude 6.8

Magnitude difference 0.1

Separation 117 arcsec

Alternative designations of θ1 Orionis

Bayer designation θ1 Orionis
(theta1 Orionis)

Flamsteed designation 41 Orionis

Henry Draper Catalogue HD37023

Hipparcos Catalogue HIP26224

Durchmusterung Catalogue BD-05 1315

General Catalogue of Variable Stars 2295

Aitken Double Star Catalogue ADS4186

In Evidence

Other stars in Orion