By: Shreya Patel


Saiph is a blue super giant that is the sixth brightest star in the constellation Orion, lying to the lower left in the Hunter's main seven-star figure. It is also the 57th brightest star in the Earth’s sky. Its name comes from a longer Arabic phrase for "sword of the giant," though it lies outside the region known today as Orion's Sword. Though at about the same distance as Rigel, Saiph looks fainter because its much higher temperature causes it to radiate much of its light in the ultraviolet part of the spectrum.

What is a Blue Super Giant?

Blue super giants are the result of millions of years of stellar evolution. Stellar evolution is the process by which a star undergoes a sequence of radical changes during it's lifetime. Depending on the mass of the star, this lifetime ranges from only a few million years for the most massive to trillions of years for the least massive.

While red super giants are the largest stars, at typical radii between 22 and 800 times the radius of our sun, blue super giants are decidedly smaller at less than 25 solar radii. Also, while red super giants tend to have very slow, yet dense stellar winds, those of blue super giants are typically very fast, yet sparse.

Blue super giants will eventually die in a supernova event. Depending on the mass of the star, the core remnant of the supernova will ultimately be a neutron star or a black hole.

How big is Saiph compared to other stars and planets?

Saiph is about the same size as Arcturus, which is shown in the fourth picture.
Big image

Important words to know

  1. Lightyear- The speed of light travels 186,282 miles per second, which is 670,616,629 mph. A lightyear is how far light travels in a year (nearly 6 trillion miles). Saiph is 720 lightyears away from Earth.
  2. Luminosity- The amount of energy. Saiph’s luminosity is 57,500 times the sun.
  3. Apparent Visual Magnitude- The apparent magnitude of a star is a measure of it's brightness as seen by an observer on Earth. Saiph shines at an apparent visual magnitude of 2.07. It looks fainter because it's much higher temperature (26,000 K) causes it to radiate much of it's light in the ultraviolet part of the spectrum.
  4. Absolute Magnitude- The magnitude (brightness) as it would be seen at a standard distance of 10 parsecs. The absolute magnitude of Saiph is 4.66

Fun Facts About Blue Supergiants

  • The lifespan of a blue supergiant star can be up to 10 million years.

  • These stars have short lifespans in comparison to most stars.

  • Blue supergiant stars are of rare occurrence in comparison to other kinds of stars. However, the luminosity of these stars makes them easily visible.

  • The process of their evolution is a bit complicated to understand. Even after years of research, the process is not completely understood, till date.

  • It is from spectral class "B".