Binary Stars: Visual and Spectroscopic

[@reemhaidar4701]

Could you tell me plz what is the simulator you used in showing Sirius motion?

[@JasonKendallAstronomer]

Stellarium.

[@JasonKendallAstronomer]

And Sky Safari.

[@astroab8523]

Thank you for this amazing astronomy lesson , i just have one small question , how can we make the difference between an eclipsing binary star and a cepheid variable , i mean they both change their brightness , how can astronomers tell one from the other ?

[@JasonKendallAstronomer]

Godo question! it's all in the shape of the light curve. Meaning exactly how fast it gets bright and dim, and how the rate of change of brightness changes with time. If you want to learn more, go on over to the American Association of Variable Star Observers website at www.aavso.org

[@astroab8523]

Jason Kendall thank you ☺☺