Return to Scale View
About News Create With Us
Return to Scale View

How big is R Doradus?

R Doradus is 410,000,000 kilometer

What Is R Doradus?

Have you ever looked up at the night sky and wondered about the stars you see? They might seem small and distant, but some are so massive that they’d dwarf our own sun. One such star is R Doradus, a red giant star that holds a fascinating record. It’s thought to be the star with the largest apparent size as seen from Earth.

Size and Comparison of R Doradus

R Doradus is not the biggest star in the universe, but it appears larger than any other stars from our view on Earth, because of its relative closeness. How big is it really? Imagine this:

  • If you were to replace our sun with R Doradus, it would stretch almost to the orbit of Venus. That’s almost 67 million miles in diameter!
  • R Doradus is about 370 times the size of our Sun.
  • If we compare it to Earth, the size differences are even more dramatic. R Doradus is nearly 410,000 times bigger than Earth.

A Closer Look at R Doradus

R Doradus is a red giant star. Red giants are stars that have used up the hydrogen fuel at their core. As a result, they expand and cool down, leading to a reddish appearance. R Doradus is located in the far-southern constellation Dorado, about 178 light-years (or 55 parsecs) away from Earth. While R Doradus is incredibly large, it’s not as hot as some other stars. Its surface temperature is about half that of the Sun. This cooler temperature contributes to its red color.

The Wonders of R Doradus

Despite its size, R Doradus isn’t visible to the naked eye. You’d need a telescope to see it. However, its size and proximity make it an exciting object for astronomers to study.

  • It has a variable brightness which changes over a cycle of about 338 days.
  • R Doradus is not alone. It’s part of a binary system, which means it has a stellar companion.
  • The star is also nearing the end of its life. In the future, it will shed its outer layers and become a white dwarf. In conclusion, R Doradus is a celestial spectacle that showcases the immense scale and diversity of the universe. From its giant size to its red glow, this star offers us a glimpse into the fascinating world beyond our own planet. So, the next time you gaze at the night sky, remember the giant R Doradus, lurking in the constellation Dorado, waiting to be explored.
Smaller By Category
Enif
Enif is an orange supergiant. Its name means "nose" in Arabic, because in the constellation Pegasus, it is in the position of the muzzle. Coincidentally, the word "Enif" backwards is "Fine".
Deneb
Deneb is the brightest star in the constellation of Cygnus. Deneb is 2,600 light-years away, which makes it the most distant of the 25 brightest stars. If you lived on Mars, Deneb would appear above the North Pole - not Polaris.
Gacrux
Gacrux can be found in the constellation Crux. Crux, which means "cross" in Latin, is known as the Southern Cross. We think Gacrux might be a binary star, but we haven't been able to spot its companion yet. The main star is a red giant.
Larger By Category
S Doradus
S Doradus is a hypergiant, as well as one of the brightest stars in the Large Magellanic Cloud. For more about the Large Magellanic Cloud, zoom out 8.5 orders of magnitude.
La Superba
La Superba is one of the reddest stars in the night sky. It is so red because of all the carbon-13 it creates when fusing helium. (Normal carbon is carbon-12.) La Superba is only 2700° C, making it one of the coldest stars.
V354 Cephei
V354 Cephei is a red supergiant, and it's huge. If placed in the Solar System, it would extend out to the asteroid belt. 354, in addition to being in this star's name, is also the year Augustine of Hippo was born.