70 Ophiuchi

70 Ophiuchi

70 Ophiuchi (p Ophiuchi) is a binary star system located 16.7 light-years away from the Earth. It shines in the constellation Ophiuchus. Though it looks like a single point of light to the naked eye, telescopes show that it is made up of two stars orbiting each other.

At magnitude 4, 70 Ophiuchi appears as a dim star to observers far from bright city lights. This means it is just barely visible without any special equipment on a clear, dark night. Many people might never notice it unless they look closely at the right part of the sky.

Binary stars like 70 Ophiuchi are important for astronomers. By studying how these two stars move around each other, scientists can learn about the mass of stars and how they form. This system gives us a close-up example of the fascinating dance that many stars perform in space.

History

This star system was listed in an old star guide written by Ptolemy in his Almagest. It was called the 28th star in the constellation Ophiuchus.

Later, a scientist named William Herschel discovered that it was made of two stars orbiting each other. He showed that these two stars were tied together by gravity. This helped prove that Newton's law of universal gravitation works even for stars far from our Solar System.

Variability

70 Ophiuchi is a variable star. This means its brightness changes a little. The two stars together shine between magnitude 4.00 and 4.03. Scientists do not know which star causes these changes or why they happen. They think it might be like other kinds of variable stars, but they still have many questions. They have measured a period of 1.92396 days for these changes.

Binary star

The 70 Ophiuchi system has two stars that move around each other. One star is yellow-orange, and the other is orange. They are sometimes far apart and sometimes closer together. They take 88 years to complete one full orbit around each other.

Claims of a planetary system

In 1855, an astronomer named William Stephen Jacob thought there might be a planet around the star system 70 Ophiuchi because its orbit looked strange. Later, other astronomers also thought the same thing, but these ideas turned out to be wrong.

Recent studies show that no planets have been found around 70 Ophiuchi, but scientists still think it’s possible that small planets could exist there.