Rasalhague
is the forty-sixth star in the Nautical Almanac. The name of this
Second Magnitude star comes from the Arabic Ras-al-hawwa, the Head of
the Snake Handler. It is also called Alpha Ophiuchi, because it is the
brightest star in the constellation of Ophiuchus The Snake Handler.
Rasalhague is a binary star system which lies about 48 light years from Earth. The system is just under a billion years old. It takes 3,148.5 days for the secondary to orbit the primary. The two stars are about 900 million miles apart.
Rasalhague Alpha seems to be leaving its Main Sequence. It is a white star of two-and-a-half times the mass and radius of the Sun. It is 25 times as bright as the Sun, and burns at a temperature of about 14,000 degrees F. It rotates fast, at almost 550,000 miles per hour, and is extremely oblate. It may in fact be coming apart under centrifugal forces.
Rasalhague Beta, which was discovered more recently, has a mass of about 0.85 that of the Sun. It is an orange star which burns at 7000 degrees F.
Orange stars like Rasalhague Beta have long life spans --- up to 30 billion years --- and are of particular interest since they develop stable planetary systems that last long enough to harbor life.
Rasalhague is a binary star system which lies about 48 light years from Earth. The system is just under a billion years old. It takes 3,148.5 days for the secondary to orbit the primary. The two stars are about 900 million miles apart.
Rasalhague Alpha seems to be leaving its Main Sequence. It is a white star of two-and-a-half times the mass and radius of the Sun. It is 25 times as bright as the Sun, and burns at a temperature of about 14,000 degrees F. It rotates fast, at almost 550,000 miles per hour, and is extremely oblate. It may in fact be coming apart under centrifugal forces.
Rasalhague Beta, which was discovered more recently, has a mass of about 0.85 that of the Sun. It is an orange star which burns at 7000 degrees F.
Orange stars like Rasalhague Beta have long life spans --- up to 30 billion years --- and are of particular interest since they develop stable planetary systems that last long enough to harbor life.
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