<p>The wikipedia article is a bit of a mess, but the Nasa value is utterly unreasonable.  752 is 10 times more massive than the minimal mass for a star, and any body with that much mass would be a star or proto-star  (or stellar remnant, I suppose, but not in this case)</p>
<p>The difficulty is in deducing the properties of the planet(s) from the disc of dust and gas that surrounds the young star, this involves building models of the disc and trying out possible planetary systems to find one that fits the observations well.</p>
<p>The first observations, in 2014 found a possible fit with a planet of mass 15-20 <span class="math-container">$M_j$</span>.  This accounts for various websites quoting &quot;15&quot;, &quot;17&quot; or &quot;20&quot; Jupiters for the mass of the planet.</p>
<p>Other groups have done their own analyses, and come up with different models of the planetary system.</p>
<p>For example, There is <a href="https://arxiv.org/abs/2110.03373" rel="nofollow noreferrer">Constraining the properties of the potential embedded planets in the disk around HD 100546</a> (Pyerin et.al, 2021) They state:</p>
<blockquote>
<p>We find that an inner planet located at <span class="math-container">$r_1=13au$</span> with a mass <span class="math-container">$M_1=8M_{Jup}$</span> and an outer planet located at <span class="math-container">$r_2=143au$</span> with a mass <span class="math-container">$M_2=3M_{Jup}$</span> leads to the best agreement between synthetic and ALMA observations.</p>
</blockquote>
<p>Recent models such as this and <a href="https://www.aanda.org/articles/aa/abs/2021/07/aa41278-21/aa41278-21.html" rel="nofollow noreferrer">(Fedele et.al, 2021)</a> come up with a two-giant-planet model.  This uncertainty combined with the &quot;wow&quot; factor for the apparent physical size of the planet suggested in 2014 explains why there are so many different values.</p>
<p>However not everyone agrees!  <a href="https://arxiv.org/abs/2206.03236" rel="nofollow noreferrer">(Cassassus et.al, 2022)</a></p>
<blockquote>
<p>tentatively propose a qualitative interpretation in terms of a surface disturbance to the Keplerian flow, i.e. a disk eruption, driven by an embedded outflow launched by a <span class="math-container">$\approx 10M_{earth}$</span> body. Another interpretation involves a disk-mass-loading hot-spot at the convergence of an envelope accretion streamer.</p>
</blockquote>
<p>Also <a href="https://ui.adsabs.harvard.edu/abs/2017AJ....153..244R/abstract" rel="nofollow noreferrer">Rameau et al 2017</a> based on <a href="https://webarchive.gemini.edu/20220203-instrumentation--gpi/" rel="nofollow noreferrer">GPI</a> data, conclude no planet:</p>
<blockquote>
<p>Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process.</p>
</blockquote>
<p>That is, no giant planet at all!</p>
<p>The conclusion is &quot;Science is hard&quot;, and it will take a bit more time, and more observations to decide exactly what is happening in this disc of gas and dust.</p>

CC BY-SA 4.0
2022-10-28T20:32:04.997Z
Also [Rameau et al 2017](https://ui.adsabs.harvard.edu/abs/2017AJ....153..244R/abstract) based on [GPI](https://webarchive.gemini.edu/20220203-instrumentation--gpi/) data, conclude no planet: "Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process. "
astrosnapper
CC BY-SA 4.0
2022-10-28T20:35:24.397Z
Thanks, I shall incorporate that verbatim.
James K
CC BY-SA 4.0
2022-10-28T20:39:10.250Z
There is additional info in the abstract such as "We detect H band emission at the location of the protoplanet HD 100546 b, but show that the choice of data processing parameters strongly affects the morphology of this source. It appears point-like in some aggressive reductions, but rejoins an extended disk structure in the majority of the others. Furthermore, we demonstrate that this emission appears stationary on a timescale of 4.6 years, inconsistent at the 2σ level with a Keplerian clockwise orbit at 59 au in the disk plane. " which didn't fit in the comment but would be good in the answer
astrosnapper
CC BY-SA 4.0
2022-10-28T17:00:27.230Z
2022-10-30T12:19:10.513Z
2022-10-30T12:19:10.513Z
James K
<p>What is HD 100546b's real mass?</p>
<p><a href="https://en.wikipedia.org/wiki/HD_100546#HD_100546_b" rel="nofollow noreferrer">In Wikipedia</a> I found that its mass is 3.1 Jupiter's masses but at <a href="https://exoplanets.nasa.gov/exoplanet-catalog/6713/hd-100546-b/" rel="nofollow noreferrer">Nasa official site</a> I found that it was 752 Jupiter masses, which sounds unbelievable.</p>
<p>And on the Internet, there are many different masses. If someone can also give a resource, it would be most welcome.</p>

CC BY-SA 4.0
2022-10-28T16:12:53.373Z
Please add links to your sources.  I've now done this for you.
James K
CC BY-SA 4.0
2022-10-28T16:25:23.090Z
I don't know where that NASA site is pulling that mass from [Exoplanet Archive](https://exoplanetarchive.ipac.caltech.edu/overview/HD%20100546) doesn't list a derived mass and lists it as "Controversial" based on algorithm-dependent detection and lack of orbital motion in a later dataset. Original paper has 1-10 $M_{jup}$ based on models but notes that the emitting area/radius is unreasonably large
astrosnapper
CC BY-SA 4.0
2022-10-29T00:18:21.893Z
It's not found in the somewhat canonical database at http://exoplanet.eu/catalog/ - probably for good reason as 752 Jupiter masses is approx 2 solar masses and not yet confirmed a planet (as James explains)
planetmaker
<exoplanet><resource-request>
What is the mass of exoplanet HD 100546b?
boring
# What is the mass of exoplanet HD 100546b?

(Asked by: username_0 on 2022-10-28)

What is HD 100546b's real mass?

[In Wikipedia](https://en.wikipedia.org/wiki/HD_100546#HD_100546_b) I found that its mass is 3.1 Jupiter's masses but at [Nasa official site](https://exoplanets.nasa.gov/exoplanet-catalog/6713/hd-100546-b/) I found that it was 752 Jupiter masses, which sounds unbelievable.

And on the Internet, there are many different masses. If someone can also give a resource, it would be most welcome.

**Tags:** exoplanet, resource-request
> **Comments:**
> **username_1**: Please add links to your sources.  I've now done this for you.  
> **username_2**: I don't know where that NASA site is pulling that mass from [Exoplanet Archive](https://exoplanetarchive.ipac.caltech.edu/overview/HD%20100546) doesn't list a derived mass and lists it as "Controversial" based on algorithm-dependent detection and lack of orbital motion in a later dataset. Original paper has 1-10 $M_{jup}$ based on models but notes that the emitting area/radius is unreasonably large  
> **username_3**: It's not found in the somewhat canonical database at http://exoplanet.eu/catalog/ - probably for good reason as 752 Jupiter masses is approx 2 solar masses and not yet confirmed a planet (as James explains)  

---

## 1 answers

### Answer by username_1 on 2022-10-28. Score: 7 | Accepted answer

The wikipedia article is a bit of a mess, but the Nasa value is utterly unreasonable. 752 is 10 times more massive than the minimal mass for a star, and any body with that much mass would be a star or proto-star (or stellar remnant, I suppose, but not in this case)

The difficulty is in deducing the properties of the planet(s) from the disc of dust and gas that surrounds the young star, this involves building models of the disc and trying out possible planetary systems to find one that fits the observations well.

The first observations, in 2014 found a possible fit with a planet of mass 15-20 $M\_j$. This accounts for various websites quoting "15", "17" or "20" Jupiters for the mass of the planet.

Other groups have done their own analyses, and come up with different models of the planetary system.

For example, There is [Constraining the properties of the potential embedded planets in the disk around HD 100546](https://arxiv.org/abs/2110.03373) (Pyerin et.al, 2021) They state:

> We find that an inner planet located at $r\_1=13au$ with a mass $M\_1=8M\_{Jup}$ and an outer planet located at $r\_2=143au$ with a mass $M\_2=3M\_{Jup}$ leads to the best agreement between synthetic and ALMA observations.

Recent models such as this and [(Fedele et.al, 2021)](https://www.aanda.org/articles/aa/abs/2021/07/aa41278-21/aa41278-21.html) come up with a two-giant-planet model. This uncertainty combined with the "wow" factor for the apparent physical size of the planet suggested in 2014 explains why there are so many different values.

However not everyone agrees! [(Cassassus et.al, 2022)](https://arxiv.org/abs/2206.03236)

> tentatively propose a qualitative interpretation in terms of a surface disturbance to the Keplerian flow, i.e. a disk eruption, driven by an embedded outflow launched by a $\approx 10M\_{earth}$ body. Another interpretation involves a disk-mass-loading hot-spot at the convergence of an envelope accretion streamer.

Also [Rameau et al 2017](https://ui.adsabs.harvard.edu/abs/2017AJ....153..244R/abstract) based on [GPI](https://webarchive.gemini.edu/20220203-instrumentation--gpi/) data, conclude no planet:

> Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process.

That is, no giant planet at all!

The conclusion is "Science is hard", and it will take a bit more time, and more observations to decide exactly what is happening in this disc of gas and dust.

> **Comments:**
> **username_2**: Also [Rameau et al 2017](https://ui.adsabs.harvard.edu/abs/2017AJ....153..244R/abstract) based on [GPI](https://webarchive.gemini.edu/20220203-instrumentation--gpi/) data, conclude no planet: "Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process. "  
> **username_1**: Thanks, I shall incorporate that verbatim.  
> **username_2**: There is additional info in the abstract such as "We detect H band emission at the location of the protoplanet HD 100546 b, but show that the choice of data processing parameters strongly affects the morphology of this source. It appears point-like in some aggressive reductions, but rejoins an extended disk structure in the majority of the others. Furthermore, we demonstrate that this emission appears stationary on a timescale of 4.6 years, inconsistent at the 2σ level with a Keplerian clockwise orbit at 59 au in the disk plane. " which didn't fit in the comment but would be good in the answer  

---

