Sirius Facts For Kids

Sirius is located at around 8.60 light-years / 2.64 parsecs away from the Earth. Keep reading for more interesting facts perfect for kids.

Sirius is the brightest star in the constellation of Canis Major and the most shining star in the night sky, except for our Sun, but this is only because Sirius is farther away from us than our Sun.

Printable Sirius Worksheets

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Sirius (α Canis Majoris) Worksheets

Key Facts & Summary

  • Sirius is located at around 8.60 light-years / 2.64 parsecs away from the Earth.
  • Sirius is designated as Alpha Canis Majoris, and it is a main-sequence star of spectral type A0 or A1.
  • Though it appears as a single star, Sirius is actually a binary star, composed out of Sirius A and Sirius B.
  • Sirius A is the primary star, while Sirius B is the companion. Sirius B is a white dwarf star of spectral type DA2.
  • Sirius has an apparent magnitude of -1.46, which is twice as bright as the second-brightest star in the night sky, Canopus.
  • Sirius is twice as big as our Sun, having 2.06 solar masses and around 1.711 solar radii.
  • Sirius is 25.4 times more luminous than our Sun.
  • The temperatures on Sirius have been recorded at 9,940 K. It is considerably hotter than our Sun.
  • However, Sirius is quite a young star, being only 242 million years old.
  • The secondary star, Sirius B, is a bit more massive than our Sun; however, it is several times smaller.
  • Sirius B, however, has surface average temperatures of around 25,000 K. This is more than four times as hot as our Sun. Sirius B is more than 100,000 times fainter than Sirius A.
  • Sirius B also appears to be younger than Sirius A, having only 228 million years.
  • The white dwarf, Sirius B, is the first white dwarf to be discovered.
  • Sirius rotates at a speed of 16 km/s. It is the first star to have its velocity measured. This happened in 1868.
  • Sirius is known as the Dog Star since it is the brightest star in the constellation of Canis Major – the larger celestial dog.
  • Sirius is the fifth closest star system to us.

Sirius Star for Kids

Sirius is the brightest star in the night sky and the brightest star in the constellation of Canis Major, the celestial greater dog. The ancients knew about Sirius due to its brightness.

The name Sirius comes from the Greek word “Seirious” which means “glowing” or “scorching,” while others know Sirius as the Dog Star. Sirius is actually moving closer to us, and because of this, its brightness will increase even further.

Sirius Characteristics

Sirius is designated as Alpha Canis Majoris, and it is a main-sequence star of spectral type A0 or A1. Though it appears as a single star, Sirius is actually a binary star, composed out of Sirius A and Sirius B.

Sirius A is the primary star, while Sirius B is the companion. Sirius B is a white dwarf star of spectral type DA2. Sirius has an apparent magnitude of -1.46, which is twice as bright as the second-brightest star in the night sky, Canopus.

Sirius is located at around 8.60 light-years / 2.64 parsecs away from the Earth. It is the fifth closest star system to us. Sirius is 25.4 times more luminous than our Sun. The temperatures on Sirius have been recorded at 9,940 K. It is considerably hotter than our Sun.

Sirius will be the brightest star in the night sky for the next 210,000 years. Over the next 60,000 years, Sirius will get even closer to Earth, and thus it will become even brighter.

Sirius B has an average surface temperature of around 25,000 K. This is more than four times as hot as our Sun. Sirius B is more than 100,000 times fainter than Sirius A.

Formation

Sirius is much younger than our Sun, as it formed around 242 million years ago. Sirius came to be from an interstellar medium of gas and dust. Gravity pulled the swirling gas and dust together and resulted in the brightest star of the constellation of Canis Major, Sirius. It is possible that the secondary star, Sirius B, also formed out of the same interstellar medium.

Fun Kids Facts About Sirius

- Stars such as Canopus or Rigel are brighter than Sirius, but Sirius is closer to us and thus appears brighter.

- The two stars in the Sirius star system were blue; however, Sirius B ran out of resources and became a white dwarf.

- The rising of Sirius marked the flooding of the Nile in ancient Egypt.

- For the ancient Greeks, Sirius marked the “dog days” – hot days – of summer.

- For the Polynesians, Sirius marked the coming of winter.

- Sirius has over 50 designations and names.

- Sometimes, Sirius flickers, and many people falsely report it as a UFO.

- The character Sirius from Harry Potter had the ability to transform himself Into a dog. It clearly is a reference to the star Sirius.

- The Dogon people of Mali in Africa knew about Sirius B and the orbital period of the Sirius star system before modern scientists did.

Size and Comparison

Sirius is more than twice as big as our Sun, having 1.711 solar radii and 2.063 solar masses. On the other hand, Sirius B is similar in size to Earth but has the Sun’s mass.

Trivia

Where is the Star Sirius Right Now?

Sirius is rising in the southeast in the hours after midnight. You can find Sirius looking in the south at dawn. Sirius will be the brightest star in the night sky for the next 210,000 years. Over the next 60,000 years, Sirius will get even closer to Earth, and thus it will become even brighter.

Is Sirius the North Star?

Sirius is not the North Star, that would be Polaris. Sirius is the brightest star in the night sky.

Why is Sirius Called the Dog Star?

Sirius is the brightest star in the constellation of Canis Major – the celestial greater dog. Due to its prominence in this constellation, Sirius is often called the dog star.

Is Sirius in the Milky Way?

Sirius is located in the Milky Way, just as our Solar System. Sirius is located at around 8.60 light-years / 2.64 parsecs away from the Earth. Sirius will forever be in the Milky Way.

Sirius Notes

- Sirius is the brightest star in the night sky and the brightest star located in the constellation of Canis Major.

- Sirius is known as the dog star since it is the brightest star in the constellation of Canis Major – the celestial greater dog.

- Sirius is a main-sequence star. It appears as a single star to the naked eye, but it is acutally a binary star system.

- The companion star, Sirius B, is a white dwarf and the first-ever white dwarf to be discovered.

- Sirius will be the brightest star in the night sky for the next 210,000 years. Over the next 60,000 years, Sirius will get even closer to Earth, and thus it will become even brighter.

Sources:

Image Sources:

  1. https://lh3.googleusercontent.com/proxy/YnL6Lw0crhsPce9m-vU2Tzl3EUEy2-JdiXftRNMBtRysfxy5SBIw4VZTATpBEwGMJAEFJP_qgjYZNA2ALj2yucvCAv_D
  2. https://www.odt.co.nz/sites/default/files/skywatch_8.jpg
  3. https://i.pinimg.com/originals/15/9e/1e/159e1e23dffad566c2c615a5d12fc3e3.jpg
  4. https://www.windows2universe.org/the_universe/images/Polaris_sm.jpg