The visual binary 70 Ophiuchi has a period of 87.7 years. the parallax of 70 Ophiuchi is 0.2 arcsec, and the apparent length of the semimajor axis as seen through a telescope is 4.5 arcsec. what is the distance to 70 Ophiuchi in parsecs? what is the actual length of the semimajor axis in AU? What is the sum of the massses of the two stars? Give your answer in solar masses.