If a star that has regular pulses(standard candle) is flying away from us at relativistic velocity(very distant), would that pulses look like very sluggish compared to a non-relativistic velocity(close to earth)...something like a clock ticking in a relativistic spaceship and....... ofcourse red-shifted.Thanks.

  • $\begingroup$ I am not very sure, what you ask. Could you please elaborate? $\endgroup$ – peterh - Reinstate Monica Aug 3 '19 at 21:35
  • $\begingroup$ Wikipedia has a detailed page on red shift and it's causes. Light already has a "built in" pulse - it has a wavelength. $\endgroup$ – StephenG Aug 4 '19 at 6:56
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    $\begingroup$ @peterh He means something like Cepheids; will their frequency change? $\endgroup$ – user1569 Aug 4 '19 at 8:29
  • $\begingroup$ Is this the same for a super nova in the sense that its explosion will last more fore an observer with a relativistic difference in velocities regards the star.Hubble law says more distant a nova is the more its speed.So more speed away from us more slower the picture of its explosion because of Lorentz law..(?) $\endgroup$ – Janko Bradvica Aug 4 '19 at 12:32
  • $\begingroup$ @JankoBradvica -- Yes. In fact, time dilation of Type Ia supernova light curves (and even the temporal evolution of their spectra) has been observed numerous times. $\endgroup$ – Peter Erwin Aug 4 '19 at 17:46

They would if we could see them far enough away, but cepheid variables are only visible up to about 20 million light years distant. That may sound like a long way, but in astronomical terms it is nearby.

  • $\begingroup$ 20 Mlyr is still enough to see a time dilation of 0.5%. $\endgroup$ – pela Aug 4 '19 at 16:37

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