Your guide to the Solar System and the night sky
🌎 Location: Greenwich, United Kingdom [change]

Propus - η Geminorum (eta Geminorum)

Propus, also designated as η Geminorum (eta Geminorum), is a variable and multiple giant star in the constellation of Gemini.

Propus visual magnitude is 3.28. Because of its moderate brightness, Propus 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 Propus:

3.28
Giant
Propus - η Geminorum (eta Geminorum) is above the horizon from Greenwich, United Kingdom [change]. Altitude: 36°.

Celestial coordinates and finder chart of Propus

Propus 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 Propus are provided in the following table:

06h 14m 52s
+22° 30’ 24”
188.85°
2.52°
Gemini

The simplified sky map below shows the position of Propus in the sky:

Finder chart Propus - η Geminorum (eta Geminorum) star
Simplified finder chart for Propus - η Geminorum (eta Geminorum).

Visibility of Propus from your location

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

Today's Propus - η Geminorum (eta Geminorum) rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 67.5°
Max altitude: 61.0°
Azimuth: 292.5°
Propus - η Geminorum (eta Geminorum) is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of Propus

The image below is a photograph of Propus 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 Propus is -0.068 arcsec per year in Right Ascension and -0.012 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of Propus - η Geminorum (eta Geminorum) star
DSS2 image of Propus. The red arrow shows the motion of Propus during the next 10000 years (-11.33 arcmin in Right Ascension and -2.00 arcmin in declination);

Distance of Propus from the Sun and relative movement

Propus is distant 349.04 light years from the Sun and it is moving far from the Sun at the speed of 19 kilometers per second.

107.07 pc
349.04 ly
19 km/s
-0.068 arcsec/year
-0.012 arcsec/year

Spectral properties of Propus

Propus belongs to spectral class M3 and has a luminosity class of III corresponding to a giant star.

-1.87
M3III
3649K

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

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

Propus star system properties

Propus 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 Propus double sysyem:

3.28
5.28
2
0 arcsec

Alternative designations of Propus

Propus
η Geminorum
(eta Geminorum)
7 Geminorum
SAO78135
SAO78135