Your Guide to the Solar System and the Night Sky
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public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 4:49  
clear_day Transit: 12:56  
SunsetSet: 21:04 south
sunny DaytimeWhat's Visible Now
All Constellations » Hydra » 


HR4172 is a hypergiant star in the constellation of Hydra.

HR4172 visual magnitude is 6.04. Because of its reltive faintness, HR4172 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 HR4172:

HR4172 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Celestial coordinates and finder chart of HR4172

HR4172 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 HR4172 are provided in the following table:

10h 38m 50s
-12° 26’ 36”

The simplified sky map below shows the position of HR4172 in the sky:

Finder chart HR4172 star
Simplified finder chart for HR4172.

Visibility of HR4172 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 HR4172 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: 102.4°
Max altitude: 26.1°
Azimuth: 257.6°
HR4172 is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of HR4172

The image below is a photograph of HR4172 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 HR4172 is -0.057 arcsec per year in Right Ascension and 0.002 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR4172 star
DSS2 image of HR4172. The red arrow shows the motion of HR4172 during the next 10000 years (-9.50 arcmin in Right Ascension and 0.33 arcmin in declination);

Distance of HR4172 from the Sun and relative movement

HR4172 is distant 358.64 light years from the Sun and it is moving far from the Sun at the speed of 12 kilometers per second.

110.01 pc
358.64 ly
12 km/s
-0.057 arcsec/year
0.002 arcsec/year

Spectral properties of HR4172

HR4172 belongs to spectral class A0 and has a luminosity class of V corresponding to a hypergiant star.


The red dot in the diagram below shows where HR4172 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR4172. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR4172