The biggest star in the sky

This is an IR Observation of R Doradus, a variable star in the constellation of Dorado (the Swordfish), located in the far southern sky. R Doradus is a variable star with a period of about 338 days, changing its magnitude from approximately 4.8 at maximum (when it is visible with the unaided eye) to 6.6 at minimum (when it requires a small telescope). R Doradus is approximately 200 light-years away.

The measured size implies that it has a physical diameter of 370 +- 50 times that of the Sun, or well over 250 million km! If R Doradus would be placed at the centre of the Solar System, its surface would be outside of the orbit of Mars. Although even bigger stars are known — Betelgeuse for one — none appears as large in the sky because they are all at greater distances. The very large apparent size of R Doradus is due to the combination of its relative proximity and large physical size.

Crédit:

ESO

À propos de l'image

Identification:eso9706a
Type:Observation
Date de publication:11 mars 1997
Communiqués de presse en rapport:eso9706
Taille:1151 x 605 px

À propos de l'objet

Nom:Gamma Reticulli, R Doradus
Type:Milky Way : Star : Evolutionary Stage : Red Giant
Milky Way : Star : Type : Variable
Catégorie:Stars

Formats des images

Grand JPEG
127,7 Kio

Fonds d'écran

1024x768
147,9 Kio
1280x1024
203,3 Kio
1600x1200
265,1 Kio
1920x1200
296,6 Kio
2048x1536
367,5 Kio

Couleurs & filtres

DomaineLongueur d'ondeTélescope
Infrarouge
Near-IR
1.25 μmNew Technology Telescope