ο Sagittarii (omicron Sagittarii)

ο Sagittarii is a variable and double giant star in the constellation of Sagittarius.

ο Sagittarii visual magnitude is 3.77. Because of its moderate brightness, ο Sagittarii 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 ο Sagittarii:

Color of ο Sagittarii ⬤

Magnitude of ο Sagittarii 3.77

Class Giant

VISIBILITY RIGHT NOW ο Sagittarii (omicron Sagittarii) is below the horizon from Greenwich, United Kingdom edit_location_alt.

Celestial coordinates and finder chart of ο Sagittarii

ο Sagittarii 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 ο Sagittarii are provided in the following table:

Right Ascension J2000 19h 04m 41s

Declination J2000 -21° 44’ 30”

Galactic Longitude 14.71°

Galactic Latitude -12.51°

Constellation Sagittarius

The simplified sky map below shows the position of ο Sagittarii in the sky:

Finder chart ο Sagittarii (omicron Sagittarii) star

Simplified finder chart for ο Sagittarii (omicron Sagittarii).

Visibility of ο Sagittarii 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 ο Sagittarii (omicron Sagittarii) 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: 111.7° RISE 23:25

Max altitude: 16.8° TRANSIT 3:27

Azimuth: 248.3° SET 7:25

RIGHT NOW ο Sagittarii (omicron Sagittarii) is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of ο Sagittarii

The image below is a photograph of ο Sagittarii 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 ο Sagittarii is 0.08 arcsec per year in Right Ascension and -0.06 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of ο Sagittarii (omicron Sagittarii) star

DSS2 image of ο Sagittarii. The red arrow shows the motion of ο Sagittarii during the next 10000 years (13.33 arcmin in Right Ascension and -10.00 arcmin in declination);

Distance of ο Sagittarii from the Sun and relative movement

ο Sagittarii is distant 138.78 light years from the Sun and it is moving far from the Sun at the speed of 25 kilometers per second.

Distance (parsec) 42.57 pc

Distance (light year) 138.78 ly

Heliocentric radial velocity 25 km/s

Proper Motion RA 0.08 arcsec/year

Proper Motion Dec -0.06 arcsec/year

Spectral properties of ο Sagittarii

ο Sagittarii belongs to spectral class G9 and has a luminosity class of III corresponding to a giant star.

Absolute magnitude 0.62

Spectral Type G9III

Color Index (B-V) 1.01

Temperature of ο Sagittarii 4719K

The red dot in the diagram below shows where ο Sagittarii is situated in the Hertzsprung–Russell diagram.

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

ο Sagittarii star system properties

ο Sagittarii 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 ο Sagittarii double sysyem:

Main star magnitude 3.77

Secondary star magnitude 13.67

Magnitude difference 9.9

Separation 35.7 arcsec

Alternative designations of ο Sagittarii

Bayer designation ο Sagittarii
(omicron Sagittarii)

Flamsteed designation 39 Sagittarii

Henry Draper Catalogue HD177241

SAO Catalogue SAO187643

Hipparcos Catalogue HIP93683

Durchmusterung Catalogue BD-21 5237

Gliese Catalogue Wo 9641

General Catalogue of Variable Stars 11703

Aitken Double Star Catalogue ADS11996

In Evidence

Other stars in Sagittarius