<p>If I understood your explanation of the problem correctly, in earlier papers, Star C was identified as a spectroscopic binary, while in the later paper based on X-ray data, it was classified as a single star. The first thing that comes to mind is that if subsystem C is a spectroscopic binary, it’s quite possible that one component has X-ray emissions while the other does not. If they are spectroscopic binaries in the sense that it's a close binary system, having X-rays from one star and not from the other is quite common.</p>
<p>Therefore, the question is in which range the star is considered single or binary, but I might not have fully understood your question</p>

CC BY-SA 4.0
2024-08-28T14:13:07.210Z
Yes, the earliest reference I could find for delta Ori C to be a spectroscopic binary is the cited 2010 paper, I don't know if there's anything earlier than that. The X-ray study was published in 2015, while the papers mentioning component C as binary are more recent (2023 and 2024). If as you say the X-ray survey could have missed the binary nature of delta Ori C (due to only one component emitting X-rays), could one say that the spectroscopic result is more reliable in this regard? The question is essentially whether the C component is actually a binary system or not.
user3764418
CC BY-SA 4.0
2024-08-28T19:28:12.080Z
yes, spectroscopic result is more reliable (if we speak in the say of existing two objects at all). The absence of X-ray from the secondary does not mean that there is no secondary at all. 

To sum up (from your words), we can say:
- Ori C is a spectroscopically binary
- only one component emits X-ray

You can find the same thoughts in the latest papers (dedicated to X-ray from Ori C) – if it is, you will see references and discussions about the binary nature of Ori C. You can also ask ChatGPT to help you in analyzing :)
Stephan Panarin
CC BY-SA 4.0
2024-08-28T12:22:32.110Z
2024-08-28T12:22:32.110Z
Stephan Panarin
<p>According to some recent studies, the star Mintaka in Orion's belt (<span class="math-container">$\delta$</span> <em>Orionis</em>) is a multiple star system consisting of 6 stars in total:</p>
<ul>
<li>the triple system <span class="math-container">$\delta$</span> Ori A, with <span class="math-container">$\delta$</span> Ori Aa1, <span class="math-container">$\delta$</span> Ori Aa2 and <span class="math-container">$\delta$</span> Ori Ab;</li>
<li>the single component <span class="math-container">$\delta$</span> Ori B;</li>
<li>the spectroscopic binary component <span class="math-container">$\delta$</span> Ori C (or <em>HD 36485</em>).</li>
</ul>
<p>The studies I'm referring to are mainly <a href="https://arxiv.org/pdf/2301.10290" rel="nofollow noreferrer">a 2023 study</a> by Oplištilová et al., which quotes <a href="https://www.semanticscholar.org/paper/The-magnetic-field-and-circumstellar-environment-of-Leone-Bohlender/37c6826aa2083ffb2d66c383b7c6b5f0ae7fd9e8" rel="nofollow noreferrer">a 2010 study</a> by Leone et al. with respect to <span class="math-container">$\delta$</span> Ori C being a binary star, and states that the system has 6 components overall:</p>
<blockquote>
<p>The bright star δ Ori (HR 1852, HD 36486, HIP 25930, ADS 4134) is a multiple stellar system consisting of six components: Aa1, Aa2, Ab, B, Ca, and Cb, more specifically, the eclipsing binary Aa1+Aa2, the interferometric binary (Aa1+Aa2)+Ab, the faint visual companion B, and the spectroscopic binary Ca+Cb</p>
</blockquote>
<p>(from the Introduction)</p>
<p><a href="https://link.springer.com/article/10.1007/s12036-024-10002-2" rel="nofollow noreferrer">This 2024 study by Malkov et al</a> confirms that <span class="math-container">$\delta$</span> Ori C is a spectroscopic binary. On page 2, they say (emphasis mine):</p>
<blockquote>
<p>HD 36486 has remote companions B and C at separation ρ = 33&quot; (V = 14.m 2, O9V) and ρ = 56&quot;
(V = 6.m 83, B2Vsn), respectively. <strong>Companion C (=HD 36485, B2Vsn) is itself a spectroscopic (SB1) binary</strong></p>
</blockquote>
<p>The <a href="https://simbad.cds.unistra.fr/simbad/sim-id?Ident=HD%2036485" rel="nofollow noreferrer">Simbad</a> database also seems to consider <span class="math-container">$\delta$</span> Ori C as a spectroscopic binary, if I'm not mistaken.</p>
<p>However, <a href="https://www.nasa.gov/universe/more-than-meets-the-eye-delta-orionis-in-orions-belt/" rel="nofollow noreferrer">this 2015 article</a> by NASA says that <span class="math-container">$\delta$</span> Ori B and C are single stars, while <span class="math-container">$\delta$</span> Ori A is a triple system, which would bring the total number of components to 5 instead of 6.
They cite studies conducted by the Chandra X-Ray observatory (a series of papers starting with <a href="https://arxiv.org/pdf/1507.04972" rel="nofollow noreferrer">this one</a> by Nichols et al.). These studies, though, seem more concerned with <span class="math-container">$\delta$</span> Ori A than with the other components, but I could be mistaken.</p>
<p>Can you explain why there is this discrepancy in the total number of stars in the system? Are there more recent studies that report <span class="math-container">$\delta$</span> Ori C as a single star and not a spectroscopic binary?</p>
<p>I'm asking this because it seems that the doubt relates only to the C component, while A and B are established as triple and single, respectively.</p>

CC BY-SA 4.0
2024-08-28T13:46:05.707Z
You nicely reference your findings - that's awesome and very well done, and it's a good question. The question will be even nicer to read, if you use the authors' names instead of "this" in the visible text :)
planetmaker
CC BY-SA 4.0
2024-08-28T14:05:59.633Z
@planetmaker I've added authors' names where missing, thanks.
user3764418
<binary-star><star-systems><orion>
Number of components in the Mintaka star system?
user3764418
# Number of components in the Mintaka star system?

(Asked by: username_0 on 2024-08-28)

According to some recent studies, the star Mintaka in Orion's belt ($\delta$ *Orionis*) is a multiple star system consisting of 6 stars in total:

* the triple system $\delta$ Ori A, with $\delta$ Ori Aa1, $\delta$ Ori Aa2 and $\delta$ Ori Ab;
* the single component $\delta$ Ori B;
* the spectroscopic binary component $\delta$ Ori C (or *HD 36485*).

The studies I'm referring to are mainly [a 2023 study](https://arxiv.org/pdf/2301.10290) by Oplištilová et al., which quotes [a 2010 study](https://www.semanticscholar.org/paper/The-magnetic-field-and-circumstellar-environment-of-Leone-Bohlender/37c6826aa2083ffb2d66c383b7c6b5f0ae7fd9e8) by Leone et al. with respect to $\delta$ Ori C being a binary star, and states that the system has 6 components overall:

> The bright star δ Ori (HR 1852, HD 36486, HIP 25930, ADS 4134) is a multiple stellar system consisting of six components: Aa1, Aa2, Ab, B, Ca, and Cb, more specifically, the eclipsing binary Aa1+Aa2, the interferometric binary (Aa1+Aa2)+Ab, the faint visual companion B, and the spectroscopic binary Ca+Cb

(from the Introduction)

[This 2024 study by Malkov et al](https://link.springer.com/article/10.1007/s12036-024-10002-2) confirms that $\delta$ Ori C is a spectroscopic binary. On page 2, they say (emphasis mine):

> HD 36486 has remote companions B and C at separation ρ = 33" (V = 14.m 2, O9V) and ρ = 56"
> (V = 6.m 83, B2Vsn), respectively. **Companion C (=HD 36485, B2Vsn) is itself a spectroscopic (SB1) binary**

The [Simbad](https://simbad.cds.unistra.fr/simbad/sim-id?Ident=HD%2036485) database also seems to consider $\delta$ Ori C as a spectroscopic binary, if I'm not mistaken.

However, [this 2015 article](https://www.nasa.gov/universe/more-than-meets-the-eye-delta-orionis-in-orions-belt/) by NASA says that $\delta$ Ori B and C are single stars, while $\delta$ Ori A is a triple system, which would bring the total number of components to 5 instead of 6.
They cite studies conducted by the Chandra X-Ray observatory (a series of papers starting with [this one](https://arxiv.org/pdf/1507.04972) by Nichols et al.). These studies, though, seem more concerned with $\delta$ Ori A than with the other components, but I could be mistaken.

Can you explain why there is this discrepancy in the total number of stars in the system? Are there more recent studies that report $\delta$ Ori C as a single star and not a spectroscopic binary?

I'm asking this because it seems that the doubt relates only to the C component, while A and B are established as triple and single, respectively.

**Tags:** binary-star, star-systems, orion
> **Comments:**
> **username_1**: You nicely reference your findings - that's awesome and very well done, and it's a good question. The question will be even nicer to read, if you use the authors' names instead of "this" in the visible text :)  
> **username_0**: @planetmaker I've added authors' names where missing, thanks.  

---

## 1 answers

### Answer by username_2 on 2024-08-28. Score: 1

If I understood your explanation of the problem correctly, in earlier papers, Star C was identified as a spectroscopic binary, while in the later paper based on X-ray data, it was classified as a single star. The first thing that comes to mind is that if subsystem C is a spectroscopic binary, it’s quite possible that one component has X-ray emissions while the other does not. If they are spectroscopic binaries in the sense that it's a close binary system, having X-rays from one star and not from the other is quite common.

Therefore, the question is in which range the star is considered single or binary, but I might not have fully understood your question

> **Comments:**
> **username_0**: Yes, the earliest reference I could find for delta Ori C to be a spectroscopic binary is the cited 2010 paper, I don't know if there's anything earlier than that. The X-ray study was published in 2015, while the papers mentioning component C as binary are more recent (2023 and 2024). If as you say the X-ray survey could have missed the binary nature of delta Ori C (due to only one component emitting X-rays), could one say that the spectroscopic result is more reliable in this regard? The question is essentially whether the C component is actually a binary system or not.  
> **username_2**: yes, spectroscopic result is more reliable (if we speak in the say of existing two objects at all). The absence of X-ray from the secondary does not mean that there is no secondary at all.   To sum up (from your words), we can say: - Ori C is a spectroscopically binary - only one component emits X-ray  You can find the same thoughts in the latest papers (dedicated to X-ray from Ori C) – if it is, you will see references and discussions about the binary nature of Ori C. You can also ask ChatGPT to help you in analyzing :)  

---

