Rigel, also known by its Bayer designation Beta Orionis (β Ori, β Orionis), is the brightest star in the constellation Orion and the seventh brightest star in the night sky, with visual magnitude 0.13. The star as seen from Earth is actually a triple star system, with the primary star (Rigel A) a blue-white supergiant of absolute magnitude −7.84 and around 120,000 times as luminous as the Sun. It has exhausted its core hydrogen and swollen out to 79 times the Sun's radius. An Alpha Cygni variable, it pulsates periodically. Visible in small telescopes and 500 times fainter than Rigel A, Rigel B is itself a spectroscopic binary system, consisting of two main sequence blue-white stars of spectral type B9V that are themselves estimated to be 2.5 and 1.9 times as massive as the Sun.
The apparent magnitude of Rigel is listed in the astronomical database SIMBAD at 0.13, making it on average the seventh brightest star in the celestial sphere excluding the Sun—just fainter than Capella. It is an irregular pulsating variable with a visual range of magnitude 0.05–0.18. Although Rigel has the Bayer designation "beta", it is almost always brighter than Alpha Orionis (Betelgeuse). Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. Rigel is the third most inherently luminous first magnitude star after Deneb and Betelgeuse. Rigel has a color index (B–V) of −0.03, meaning it appears white or lightly blue-white.
Rigel is the name of an Argentinian sounding rocket. The double stage Rigel (first stage Canopus 1, second stage Orion-2) was launched seven times between 1969 and 1973. The Rigel rocket has a maximum altitude of 310 km, a launch mass of 300 kg, a diameter of 0.228 metres and a length of 6.30 metres.
Rigel was a large black Newfoundland dog who was said to have saved some of the survivors of the sinking of the RMS Titanic. One account of the story was published in the New York Herald, April 21, 1912, the other was the book Sinking of the Titanic and Great sea disasters by Logan Marshall, published 1912. However, although the story has been widely reproduced, there is certain doubt about whether the dog actually existed.
Rigel was said to have been owned by William McMaster Murdoch, the First Officer of the Titanic. Murdoch died in the sinking, but Rigel swam away, and stayed close to one of the lifeboats. When RMS Carpathia arrived on the scene looking for survivors, Rigel began to bark. The lifeboat had drifted under the bows of the Carpathia, and was at risk of being run down, but the people in the boat were too exhausted to make themselves heard. Rigel's barks alerted Captain Arthur Rostron, who ordered the engines stopped and began the search for survivors. Everyone in the lifeboat was saved, and Rigel was pulled from the icy water after three hours, unaffected by the experience. The dog was too large to be pulled from the water by hand, but Jonas Briggs managed to get a canvas sling under its belly, with which it was hauled aboard.