<p>In 2014 and 15, an <a href="https://en.wikipedia.org/wiki/U_(TNO)" rel="noreferrer">object called U</a> has been detected by the ALMA in Chile, considered likely to be a super-Earth at 300 AU, among other options. Is it located where the hypothetical super-Earth supposedly responsible for ETNO's orbits is believed to be? Has there been any progress since 2015 in finding out what the U object is?</p>

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2021-06-30T15:00:37.560Z
Cool question! From the Wikipedia article: *A new submm source within a few arcseconds of α Centauri: ALMA discovers the most distant object of the solar system* https://arxiv.org/abs/1512.02652v1
uhoh
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2021-06-30T15:04:30.823Z
I note that the papers about U have not been cited; that suggests to me that the astronomy community has not been very convinced about it.
Anders Sandberg
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2021-06-30T15:11:32.940Z
@AndersSandberg I don't think the purpose of putting it up on arXive was to convince anyone of anything. I've just quoted one of the authors: https://astronomy.stackexchange.com/a/44666/7982 There may simply be no place where it is currently appropriate to cite this type of publication of early data for the purposes of discussion. However it seems that there would have been some follow-up observations and those, if published, would cite this work. I wonder if someone submitted a proposal and it wasn't accepted?
uhoh
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2021-06-30T17:20:19.277Z
@uhoh - If somebody states something fairly radical that seems like it would matter to a lot of research and the result is silence, then that seems to imply a lot about how credible people find it. I would still expect at least a few papers pointing out why the findings were wrong, though. Total silence is relatively rare.
Anders Sandberg
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2021-06-30T18:08:52.020Z
@AndersSandberg The Wikipedia article writes that ALMA has a narrow FOV, therefore Brown believed it unlikely. However, U's detection happened before the proposition of another planet by Batigyn and Brown himself. I wonder if U is in the direction they proposed the planet. The article further writes how another astronomer, Bruce Macintosh suggests it were _maybe_ artifacts due to ALMA's calibration methods.
John
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2021-06-30T23:18:09.787Z
@AndersSandberg I skimmed that arXiv preprint and found no radical statements; which statement there do you think might be thought of as radical?
uhoh
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2021-07-01T00:43:41.910Z
Liseau posted a follow-up in 2019: https://arxiv.org/abs/1904.03043
Mike G
<observational-astronomy><9th-planet><hypothetical>
What about the U planet?
John
# What about the U planet?

(Asked by: username_0 on 2021-06-30)

In 2014 and 15, an [object called U](https://en.wikipedia.org/wiki/U_(TNO)) has been detected by the ALMA in Chile, considered likely to be a super-Earth at 300 AU, among other options. Is it located where the hypothetical super-Earth supposedly responsible for ETNO's orbits is believed to be? Has there been any progress since 2015 in finding out what the U object is?

**Tags:** observational-astronomy, 9th-planet, hypothetical

> **Comments:**
> **username_1**: Cool question! From the Wikipedia article: *A new submm source within a few arcseconds of α Centauri: ALMA discovers the most distant object of the solar system* https://arxiv.org/abs/1512.02652v1  
> **username_2**: I note that the papers about U have not been cited; that suggests to me that the astronomy community has not been very convinced about it.  
> **username_1**: @username_2 I don't think the purpose of putting it up on arXive was to convince anyone of anything. I've just quoted one of the authors: https://astronomy.stackexchange.com/a/44666/7982 There may simply be no place where it is currently appropriate to cite this type of publication of early data for the purposes of discussion. However it seems that there would have been some follow-up observations and those, if published, would cite this work. I wonder if someone submitted a proposal and it wasn't accepted?  
> **username_2**: @username_1 - If somebody states something fairly radical that seems like it would matter to a lot of research and the result is silence, then that seems to imply a lot about how credible people find it. I would still expect at least a few papers pointing out why the findings were wrong, though. Total silence is relatively rare.  
> **username_0**: @username_2 The Wikipedia article writes that ALMA has a narrow FOV, therefore Brown believed it unlikely. However, U's detection happened before the proposition of another planet by Batigyn and Brown himself. I wonder if U is in the direction they proposed the planet. The article further writes how another astronomer, Bruce Macintosh suggests it were _maybe_ artifacts due to ALMA's calibration methods.  
> **username_1**: @username_2 I skimmed that arXiv preprint and found no radical statements; which statement there do you think might be thought of as radical?  
> **username_3**: Liseau posted a follow-up in 2019: https://arxiv.org/abs/1904.03043  

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## 0 answers

