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: 4:50  
clear_day Transit: 12:56  
SunsetSet: 21:02 south
sunny DaytimeWhat's Visible Now
All Constellations » Orion » 


HR1840 is a sub-giant star in the constellation of Orion.

HR1840 visual magnitude is 6.33. Because of its reltive faintness, HR1840 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 HR1840:

HR1840 is above the horizon from Greenwich, United Kingdom edit_location_alt. Altitude: 22°.

Celestial coordinates and finder chart of HR1840

HR1840 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 HR1840 are provided in the following table:

05h 30m 20s
-07° 26’ 04”

The simplified sky map below shows the position of HR1840 in the sky:

Finder chart HR1840 star
Simplified finder chart for HR1840.

Visibility of HR1840 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 HR1840 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: 97.4°
Max altitude: 31.1°
Azimuth: 262.6°
HR1840 is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of HR1840

The image below is a photograph of HR1840 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 HR1840 is -0.013 arcsec per year in Right Ascension and 0.001 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of HR1840 star
DSS2 image of HR1840. The red arrow shows the motion of HR1840 during the next 10000 years (-2.17 arcmin in Right Ascension and 0.17 arcmin in declination);

Distance of HR1840 from the Sun and relative movement

HR1840 is distant 1,216.42 light years from the Sun and it is moving far from the Sun at the speed of 11 kilometers per second.

373.13 pc
1,216.42 ly
11 km/s
-0.013 arcsec/year
0.001 arcsec/year

Spectral properties of HR1840

HR1840 belongs to spectral class B2 and has a luminosity class of IV corresponding to a sub-giant star.


The red dot in the diagram below shows where HR1840 is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of HR1840. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR1840