Based on the changes in the light curve and the behavior of the series of spectra, this is a<u> binary system. </u>
<h3>How is this is binary system?</h3>
The characteristics described are those of a binary system with the specific type of system being the spectroscopic binary system.
This is because in a spectroscopic binary system, there won't be significant changes in brightness but as a result of stars orbiting towards and then away from us, spectral features will appear as alternative absorption lines.
In conclusion, this is a binary system.
Find out more on binary systems at brainly.com/question/15868824.
We have that the speed of the object between 60 to 70 seconds

From the question we are told
The speed of the object between 60 to 70 seconds
Generally the equation for Average speed is mathematically given as

Where

Therefore

In conclusion
The speed of the object between 60 to 70 seconds

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So picture below to see answer and explanation.