<p>It may just be a case of terminology. I know that in atmospheric science the term 'retrieval' is quite common, but not so much in astrophysics. Certainly, in solar physics for instance inverse methods have been used for a long time. See this review paper for instance <a href="https://arxiv.org/abs/1609.08324" rel="nofollow noreferrer">https://arxiv.org/abs/1609.08324</a> . To some extent, these 'inverse' methods are just iterated forward methods anywa</p>

CC BY-SA 4.0
2022-02-20T22:06:56.547Z
2022-02-21T18:26:29.867Z
2022-02-21T18:26:29.867Z
Thomas
<p>Although there are lots of examples of atmospheric retrieval techniques being used on exoplanets, and recently brown dwarfs, I can't find any mention of atmospheric retrieval techniques being used on stars. Is this because:</p>
<p>a) My research is bad and there are examples of this?</p>
<p>b) It's not useful as the structure and profile of stars are well known, as well as how to determine parameters e.g. metallicity by UV absorption?</p>
<p>c) Another reason?</p>
<p>Any help would be greatly appreciated.</p>

CC BY-SA 4.0
2022-02-17T22:03:38.173Z
I think I’m missing something here, when you say atmosphere retrieval are you referring to just spectroscopy on planets or something a bit more nuanced? If just spectroscopy, then spectroscopy certainly exists on stars and has existed for a very long time.
Justin T
CC BY-SA 4.0
2022-02-17T22:07:44.000Z
And if you’re referring to finding stellar structure/ temperature profiles/ etc from spectroscopy as is done with planets, then this is done as well for stars, but probe slightly different characteristics since certain broad strokes about the stellar structure have been determined a long time ago through means including spectroscopic methods (convective vs radiative zones, core structure, etc)
Justin T
CC BY-SA 4.0
2022-02-18T15:18:47.370Z
@JustinT I am referring to using primarily Bayesian techniques to solve the inverse model problem rather than the forward model problem - for example please see here:
https://arxiv.org/abs/1808.04824
It's discussed at length in Rodgers (2000) for atmospheric sounding.
Bad_physicist
CC BY-SA 4.0
2022-02-20T10:27:51.347Z
It may just be a case of terminology. I know that in atmospheric science the term 'retrieval' is quite common, but not so in astrophysics. Certainly, in solar physics for instance inverse methods have been used for a long time. See this review paper for instance https://arxiv.org/abs/1609.08324  To some extent, these 'inverse' methods are just iterated forward methods anyway.
Thomas
CC BY-SA 4.0
2022-02-20T17:38:53.093Z
@Thomas Thanks for this - it is exactly what I was looking for!
Bad_physicist
CC BY-SA 4.0
2022-02-20T18:57:37.617Z
I can add my comment as an answer as well if you want (I wasn't quite sure whether this would qualify as an answer for you)
Thomas
CC BY-SA 4.0
2022-02-20T19:28:12.390Z
@thomas do make it an answer, otherwise there is nothing to vote for and the question will keep being recycled. The system needs answers as answers.
James K
CC BY-SA 4.0
2022-02-20T21:24:08.817Z
@Thomas Please do so I can set this as answered
Bad_physicist
<exoplanet><brown-dwarf><modeling><stellar-atmospheres>
Can we use atmospheric retrieval techniques on stars?
Bad_physicist
# Can we use atmospheric retrieval techniques on stars?

(Asked by: username_0 on 2022-02-17)

Although there are lots of examples of atmospheric retrieval techniques being used on exoplanets, and recently brown dwarfs, I can't find any mention of atmospheric retrieval techniques being used on stars. Is this because:

a) My research is bad and there are examples of this?

b) It's not useful as the structure and profile of stars are well known, as well as how to determine parameters e.g. metallicity by UV absorption?

c) Another reason?

Any help would be greatly appreciated.

**Tags:** exoplanet, brown-dwarf, modeling, stellar-atmospheres
> **Comments:**
> **username_1**: I think I’m missing something here, when you say atmosphere retrieval are you referring to just spectroscopy on planets or something a bit more nuanced? If just spectroscopy, then spectroscopy certainly exists on stars and has existed for a very long time.  
> **username_1**: And if you’re referring to finding stellar structure/ temperature profiles/ etc from spectroscopy as is done with planets, then this is done as well for stars, but probe slightly different characteristics since certain broad strokes about the stellar structure have been determined a long time ago through means including spectroscopic methods (convective vs radiative zones, core structure, etc)  
> **username_0**: @JustinT I am referring to using primarily Bayesian techniques to solve the inverse model problem rather than the forward model problem - for example please see here: https://arxiv.org/abs/1808.04824 It's discussed at length in Rodgers (2000) for atmospheric sounding.  
> **username_2**: It may just be a case of terminology. I know that in atmospheric science the term 'retrieval' is quite common, but not so in astrophysics. Certainly, in solar physics for instance inverse methods have been used for a long time. See this review paper for instance https://arxiv.org/abs/1609.08324  To some extent, these 'inverse' methods are just iterated forward methods anyway.  
> **username_0**: @Thomas Thanks for this - it is exactly what I was looking for!  
> **username_2**: I can add my comment as an answer as well if you want (I wasn't quite sure whether this would qualify as an answer for you)  
> **username_3**: @thomas do make it an answer, otherwise there is nothing to vote for and the question will keep being recycled. The system needs answers as answers.  
> **username_0**: @Thomas Please do so I can set this as answered  

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## 1 answers

### Answer by username_2 on 2022-02-20. Score: 0 | Accepted answer

It may just be a case of terminology. I know that in atmospheric science the term 'retrieval' is quite common, but not so much in astrophysics. Certainly, in solar physics for instance inverse methods have been used for a long time. See this review paper for instance <https://arxiv.org/abs/1609.08324> . To some extent, these 'inverse' methods are just iterated forward methods anywa


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