HR18

HR18 is a variable hypergiant star in the constellation of Cetus.

HR18 visual magnitude is 6.06. Because of its reltive faintness, HR18 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 HR18:

Color of HR18 ⬤

Magnitude of HR18 6.06

Class Hypergiant

VISIBILITY RIGHT NOW HR18 is below the horizon from Greenwich, United Kingdom edit_location_alt.

Celestial coordinates and finder chart of HR18

HR18 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 HR18 are provided in the following table:

Right Ascension J2000 00h 08m 33s

Declination J2000 -17° 34’ 39”

Galactic Longitude 74.69°

Galactic Latitude -76.25°

Constellation Cetus

The simplified sky map below shows the position of HR18 in the sky:

Simplified finder chart for HR18.

Visibility of HR18 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 HR18 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: 107.6° RISE 4:21

Max altitude: 20.9° TRANSIT 8:46

Azimuth: 252.4° SET 13:10

RIGHT NOW HR18 is below the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of HR18

The image below is a photograph of HR18 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 HR18 is 0 arcsec per year in Right Ascension and -0.025 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

DSS2 image of HR18. The red arrow shows the motion of HR18 during the next 10000 years (0.00 arcmin in Right Ascension and -4.17 arcmin in declination);

Distance of HR18 from the Sun and relative movement

HR18 is distant 1,347.11 light years from the Sun and it is moving towards the Sun at the speed of 17 kilometers per second.

Distance (parsec) 413.22 pc

Distance (light year) 1,347.11 ly

Heliocentric radial velocity -17 km/s

Proper Motion Dec -0.025 arcsec/year

Spectral properties of HR18

HR18 belongs to spectral class M0 and has a luminosity class of III corresponding to a hypergiant star.

Absolute magnitude -2.02

Spectral Type M0III

Color Index (B-V) 1.67

Temperature of HR18 3555K

The red dot in the diagram below shows where HR18 is situated in the Hertzsprung–Russell diagram.

H-R diagram showing the position of HR18. Attribution: Richard Powell / CC BY-SA

Alternative designations of HR18

Henry Draper Catalogue HD402

SAO Catalogue SAO147103

Hipparcos Catalogue HIP696

Durchmusterung Catalogue BD-18 3

General Catalogue of Variable Stars 51

In Evidence

Other stars in Cetus