<p>Accounting for the transverse Doppler effect (and other relativistic effects) is essential in modelling the X-ray spectral emission lines from the accretion discs around black holes (e.g. <a href="https://academic.oup.com/mnras/article/363/1/177/1299829" rel="noreferrer">Cadaz &amp; Calvani 2005</a>). In this case the transverse Doppler effect is "mixed up" with gravitational redshift and it is treated holistically in the Schwarzschild or Kerr metrics.</p>

<p>The transverse Doppler effect is also essential in interpreting the signals from binary pulsars and even in single pulsars because of the rotation of the Earth and its motion around the Sun.</p>

CC BY-SA 4.0
2018-11-18T16:35:37.027Z
@BenCrowell - All true, except there are now possibilities with precisely measured proper motions and parallaxes to have an independent measure of transverse velocity.
ProfRob
CC BY-SA 4.0
2018-11-20T01:28:09.970Z
Can you check my understanding that about 25km/s or more is enough to measure the transverse velocity with the transverse doppler effect? (Source: https://lm.facebook.com/l.php?u=http%3A%2F%2Fadsbit.harvard.edu%2Ffull%2F1997MNRAS.291L..63O%2FL000064.000.html%3Ffbclid%3DIwAR0pNODDhbWNZdzqYrSdYD8W89694zJChQQbWh1RcebVyxIKZEcZeZMX3MQ&h=AT1-2jkTyWs4hiBUsqHhD5FI0wH4Poad-8W0aIGWORMXirPfomPh9wh6qgvXNMzRDhMgyn08OATKxtL9_B03E4Y4ysCb7u3fQczsHCLNAyOmRhKy52oqmfBtU6jr516W7OjXE64uiQ)
Hyeonseo Yang
CC BY-SA 4.0
2018-11-18T11:36:31.947Z
2018-11-18T11:36:31.947Z
ProfRob
<p>Are there any astronomical examples where the transverse doppler effect(Horizontal doppler effect) is applied (Derives a meaningful result)?</p>

<light><special-relativity><doppler-effect>
Are there any examples where the transverse doppler effect is applied in astronomy?
YYJ
# Are there any examples where the transverse doppler effect is applied in astronomy?

(Asked by: username_0 on 2018-11-18)

Are there any astronomical examples where the transverse doppler effect(Horizontal doppler effect) is applied (Derives a meaningful result)?

**Tags:** light, special-relativity, doppler-effect

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## 1 answers

### Answer by username_1 on 2018-11-18. Score: 6 | Accepted answer

Accounting for the transverse Doppler effect (and other relativistic effects) is essential in modelling the X-ray spectral emission lines from the accretion discs around black holes (e.g. [Cadaz & Calvani 2005](https://academic.oup.com/mnras/article/363/1/177/1299829)). In this case the transverse Doppler effect is "mixed up" with gravitational redshift and it is treated holistically in the Schwarzschild or Kerr metrics.

The transverse Doppler effect is also essential in interpreting the signals from binary pulsars and even in single pulsars because of the rotation of the Earth and its motion around the Sun.

> **Comments:**
> **username_1**: @BenCrowell - All true, except there are now possibilities with precisely measured proper motions and parallaxes to have an independent measure of transverse velocity.  
> **username_2**: Can you check my understanding that about 25km/s or more is enough to measure the transverse velocity with the transverse doppler effect? (Source: https://lm.facebook.com/l.php?u=http%3A%2F%2Fadsbit.harvard.edu%2Ffull%2F1997MNRAS.291L..63O%2FL000064.000.html%3Ffbclid%3DIwAR0pNODDhbWNZdzqYrSdYD8W89694zJChQQbWh1RcebVyxIKZEcZeZMX3MQ&h=AT1-2jkTyWs4hiBUsqHhD5FI0wH4Poad-8W0aIGWORMXirPfomPh9wh6qgvXNMzRDhMgyn08OATKxtL9_B03E4Y4ysCb7u3fQczsHCLNAyOmRhKy52oqmfBtU6jr516W7OjXE64uiQ)  

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