Your Guide to the Solar System and the Night Sky
This site is free and ad-free thanks to the support of our users. If you can, please consider a donation.
public Observing fromLocation: Greenwich, United Kingdom edit_location_alt
north SunriseRise: 6:55  
clear_day Transit: 12:49  
SunsetSet: 18:41 south
sunny DaytimeWhat's Visible Now
All Constellations » Orion » 


Altitude: -32.6°   Azimuth: 321.8°   Direction: North-West

HR1681 is a hypergiant star in the constellation of Orion.

HR1681 visual magnitude is 6.1. Because of its reltive faintness, HR1681 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 HR1681:


HR1681 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Altitude: -32.6°
Azimuth: 321.8°
Direction: North-West

Celestial coordinates and finder chart of HR1681

HR1681 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 HR1681 are provided in the following table:

05h 10m 03s
-00° 33’ 55”

The simplified sky map below shows the position of HR1681 in the sky:

Finder chart HR1681 star
Simplified finder chart for HR1681.

Visibility of HR1681 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 HR1681 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: 90.6°
Max altitude: 38.0°
Azimuth: 269.4°

Digitized Sky Survey image of HR1681

The image below is a photograph of HR1681 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 HR1681 is 0.001 arcsec per year in Right Ascension and -0.053 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR1681 star
DSS2 image of HR1681. The red arrow shows the motion of HR1681 during the next 10000 years (0.17 arcmin in Right Ascension and -8.83 arcmin in declination);

Distance of HR1681 from the Sun and relative movement

HR1681 is distant 314.37 light years from the Sun and it is moving far from the Sun at the speed of 26 kilometers per second.

96.43 pc
314.37 ly
26 km/s
0.001 arcsec/year
-0.053 arcsec/year

Spectral properties of HR1681

HR1681 belongs to spectral class K0 and has a luminosity class of III corresponding to a hypergiant star.


The red dot in the diagram below shows where HR1681 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR1681. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR1681