<p>I have a spectra of an M dwarf and I would like to remove the Doppler shift effects due to a known exoplanet, with known planetary parameters, from the whole spectra of the star. I have shifted/corrected the spectra for the radial velocity of the star itself along the line-of-sight but I'm not sure how to shift/correct it for the wobble of the star around a common centre of mass due to a planet orbiting it. Can someone please help?</p>

CC BY-SA 4.0
2021-04-06T12:38:35.947Z
Do you have more than one spectrum?  Or just a single spectrum at one particular time?  If it’s the latter, then it’s a simple Doppler shift correction, as you’ve already done (assuming you somehow know what the size of the velocity shift from the planet is).  If you have multiple spectra, then you would need to know the planet’s orbit, and thus what the velocity of the star would be, at each point, but it’s still just a Doppler shift correction.
Eric Jensen
CC BY-SA 4.0
2021-04-06T15:06:40.703Z
@EricJensen that basically is the answer IMHO.
planetmaker
<spectroscopy><doppler-effect>
How to remove radial velocity effects of an exoplanet from the host star spectra?
Mukul Kumar
# How to remove radial velocity effects of an exoplanet from the host star spectra?

(Asked by: username_0 on 2021-04-06)

I have a spectra of an M dwarf and I would like to remove the Doppler shift effects due to a known exoplanet, with known planetary parameters, from the whole spectra of the star. I have shifted/corrected the spectra for the radial velocity of the star itself along the line-of-sight but I'm not sure how to shift/correct it for the wobble of the star around a common centre of mass due to a planet orbiting it. Can someone please help?

**Tags:** spectroscopy, doppler-effect
> **Comments:**
> **username_1**: Do you have more than one spectrum?  Or just a single spectrum at one particular time?  If it’s the latter, then it’s a simple Doppler shift correction, as you’ve already done (assuming you somehow know what the size of the velocity shift from the planet is).  If you have multiple spectra, then you would need to know the planet’s orbit, and thus what the velocity of the star would be, at each point, but it’s still just a Doppler shift correction.  
> **username_2**: @EricJensen that basically is the answer IMHO.  

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## 0 answers

