Take a Journey of Discovery with RXTE - Classroom Activity

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Your light curve expert team receives a report from the spectrum team analyzing the spectrum of the mystery object.

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Spectrum Team Report

From:Spectrum Team
To: Drew Freeman Research Facility

  • The lines in the spectrum show that the star is a K type red star. Stars of that type usually have a mass of 0.7 times the mass of the Sun.

  • The spectal lines also show that the star is moving at a maximum speed of 457 km/s around the star that is the source of our X-rays.

  • The two stars orbit each other once every 7.7 hours.

  • From this information, we have calculated that the total mass of the system is 5.0 times the mass of the sun. This means that the mass of the Mystery X-ray Source is equal to the mass of the system minus the mass of the companion star.

    5.0 - 0.7 = 4.3

    The Mystery Source is 4.3 times the mass of the Sun.

Using the information in this report, your team should now be able to accurately identify the source of the X-ray emission. (Hint: Reread the links on black holes and neutron stars.)

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