<p>Unfortunately, I have not found much information. On the website of the &quot;<em>Societé Astronomique de France</em>&quot; they say:</p>
<p><em>A team of researchers from Paris Observatory – PSL under the direction of Dr. Miguel Montargès (author of the study published in Nature, &quot;<em>A dusty veil shading Betelgeuse during its Great Dimming</em>&quot;) is mobilizing the amateur astronomer community <strong>to acquire photometric and spectroscopic data</strong> on this occasion.
The collected data will be used <strong>to characterize Betelgeuse’s photosphere in the visible and, potentially, to reconstruct its image and the velocity distribution of the convective cells</strong></em>.</p>
<p>Ref. <a href="https://saf-astronomie.fr/loccultation-de-betelgeuse-par-lasteroide-319-leona-le-12-decembre-2023/" rel="nofollow noreferrer"><strong>Occultation of Betelgeuse by asteroid (319) Leona on 12/12/2023 – Press release</strong></a></p>
<p>I also found: <em>Asteroidal occultations of stars are frequent phenomena but the occultation of Betelgeuse by Leona will be extremely important and unique. It represents an extraordinary opportunity <strong>to analyze the diameter and brightness distribution of Betelgeuse’s photosphere</strong> by studying the light curve as the asteroid progressively occults the star from different points on Earth and at different wavelengths. In the overwhelming majority of the stellar occultations the diameters of the stars are tiny compared to the angular size of the solar system body that passes in front of them so the occultations are not gradual, but in this case, the huge angular diameter of Betelgeuse will give rise to a different phenomenon of “partial eclipse” and “total eclipse” (provided that Leona’s angular diameter is large enough compared with that of Betelgeuse)</em>.</p>
<p>Ref. <a href="https://arxiv.org/abs/2309.12272" rel="nofollow noreferrer"><strong>The stellar occultation by (319) Leona on 13 September 2023 in preparation for the occultation of Betelgeuse</strong></a></p>
<p>The &quot;International Occultation Timing Association / European Section e.V.&quot; made a <a href="https://www.iota-es.de/betelgeuse2023.html" rel="nofollow noreferrer"><strong>Call for Observations: Occultation of Betelgeuse by (319) Leona on 2023 Dec 12</strong></a></p>
<p>And they have published on their website a follow-up of the occultation: <a href="https://call4obs.iota-es.de/news-feed-occultation-of-betelgeuse-by-319-leona" rel="nofollow noreferrer"><strong>News Feed – Occultation of Betelgeuse by (319) Leona</strong></a></p>
<p>This Spanish website invites amateur astronomers to make observations of the occultation: <a href="https://starblink.org/ocultacion_betelgeuse" rel="nofollow noreferrer"><strong>La ocultación de Betelgeuse del 12 de diciembre de 2023</strong></a></p>
<p>The dimming of Betelgeuse due to the occultation, captured by an amateur in Spain this past night, can be seen here, (Betelgeuse is the bright star at the top, a little to the left).</p>
<p><a href="https://www.youtube.com/watch?v=KlIjVjqcnmE" rel="nofollow noreferrer"><strong>Occultation of Betelgeuse (Betelgeuze) by 319 Leona</strong> (Jörg Schoppmeyer)</a></p>
<p>Best regards.</p>
<p><strong>UPDATED:</strong> Light curves and videos of the occultation are being uploaded: <a href="https://call4obs.iota-es.de/observations-of-the-occultation-of-betelgeuse-by-319-leona" rel="nofollow noreferrer"><strong>Observations of the Occultation of Betelgeuse by (319) Leona (IOTA/ES)</strong></a></p>

CC BY-SA 4.0
2023-12-12T15:12:31.117Z
2023-12-14T07:19:14.880Z
2023-12-14T07:19:14.880Z
Albert
<p>On <a href="https://www.virtualtelescope.eu/webtv/" rel="nofollow noreferrer">https://www.virtualtelescope.eu/webtv/</a>, Gianluca Masi, the Italian astronomer and developer of &quot;THE VIRTUAL TELESCOPE PROJECT&quot;, has posted the following announcement :</p>
<blockquote>
<p>Next event: “Betelgeuse occultation by Leona: live view” – 12 Dec. 2023, starting at 01:00 UTC</p>
</blockquote>
<p>The Virual Telescope Project uses multiple robotic telescopes to perform observations.</p>
<p>More details here: <a href="https://www.virtualtelescope.eu/2023/12/04/the-extremely-rare-betelgeuse-occultation-by-asteroid-319-leona-online-event-12-dec-2023/" rel="nofollow noreferrer">https://www.virtualtelescope.eu/2023/12/04/the-extremely-rare-betelgeuse-occultation-by-asteroid-319-leona-online-event-12-dec-2023/</a></p>

CC BY-SA 4.0
2023-12-10T12:09:19.667Z
That's interesting to know - but it misses at least half the #question of "what can be learned" or "what do they expect to learn" (however the question title is broader than explained in the question...)
planetmaker
CC BY-SA 4.0
2023-12-10T20:22:23.593Z
I think this is for entertainment purposes for the public to watch, rather than for astronomical measurements. I would not call this a real astronomical observation campaign.
uhoh
CC BY-SA 4.0
2023-12-10T10:28:21.037Z
2023-12-10T20:30:42.837Z
2023-12-10T20:30:42.837Z
usernumber
<p>There's a lot of interest in <a href="https://en.wikipedia.org/wiki/Betelgeuse" rel="noreferrer">Betelgeuse</a> party because of it's recent fainting behavior, and despite being so close, the huge uncertainty in it's distance due to its fickle photocenter:</p>
<ul>
<li><a href="https://astronomy.stackexchange.com/q/39427/7982">Can New Horizons be used to measure the distance to Betelgeuse (despite its fickle photocenter)?</a></li>
<li><a href="https://astronomy.stackexchange.com/q/36365/7982">What will it finally take to accurately measure the distance to Betelgeuse?</a></li>
<li><a href="https://astronomy.stackexchange.com/q/34545/7982">Did the late 2019 &quot;fainting&quot; of Betelgeuse show any spectral trends that differ from it&#39;s normal variability?</a></li>
<li><a href="https://astronomy.stackexchange.com/q/35451/7982">Why does titanium oxide around Betelgeuse produce this particular sawtooth-shaped absorption spectrum?</a></li>
<li><a href="https://astronomy.stackexchange.com/q/34547/7982">When we say a variable star is &quot;fainting&quot; does it mean something more or different than &quot;dimming&quot; or &quot;fading&quot;?</a></li>
</ul>
<p>Soon the asteroid <a href="https://en.wikipedia.org/wiki/319_Leona" rel="noreferrer">319 Leona</a> will pass in front of Betelgeuse.</p>
<ul>
<li><a href="https://cloud.occultwatcher.net/event/1075-319-83995-648466-H27989#" rel="noreferrer">https://cloud.occultwatcher.net/event/1075-319-83995-648466-H27989#</a></li>
</ul>
<p><strong>Question:</strong> Is this occultation a rare and valuable opportunity to learn things about Betelgeuse itself and whatever might be around it (e.g. dust rings, etc.)? If so, what's been organized to maximize the granularity and diversity of measurements?</p>

CC BY-SA 4.0
2023-12-07T02:35:19.650Z
FWIW, 319 Leona has been in retrograde motion since early November and will resume prograde motion in early February. Here's a geocentric plot of its J2000 ecliptic longitude & latitude, using a 2 day timestep https://i.sstatic.net/XhHoT.png (with numeric labels every 30 days)
PM 2Ring
CC BY-SA 4.0
2023-12-07T05:05:46.333Z
@PM2Ring *Beautiful!* I'll bet you can add Betelgeuse's trajectory fairly easily (hint hint) :-)
uhoh
CC BY-SA 4.0
2023-12-07T06:24:18.180Z
The ecliptic coords of Betelgeuse are lon 88.755, lat -16.027. That plot is from the centre of the Earth, so it's of limited use in determining the exact time of occultation. I only posted it to give a rough idea of how 319 Leona is currently moving.
PM 2Ring
CC BY-SA 4.0
2023-12-07T06:52:00.107Z
@PM2Ring ya, Betelgeuse has a substantial parallax, but at this scale its motion is invisible and the intersection with Earth's surface (rather than center) even "invisibler", but I feel better seeing the dot anyway https://i.sstatic.net/ji9cq.png
uhoh
CC BY-SA 4.0
2023-12-11T19:51:58.327Z
Discussed on Phil Plaits newsletter https://badastronomy.substack.com/p/big-body-briefly-blocks-betelgeuse
James K
CC BY-SA 4.0
2023-12-14T06:00:24.313Z
Something similar happened in [2022 regarding Pluto](https://www.abc.net.au/news/2022-06-12/nasa-scientists-in-australian-outback-searching-for-pluto/101130096) to get a "weather report" for Pluto. Apparently Mike Skrutskie of U Virginia is a seasoned occultation observer, and does events like this a couple of times a week at home, “but mostly asteroids”. Apparently it is how the [rings or Uranus & Neptune were found](https://spaceaustralia.com/news/northern-territory-rural-students-observe-plutos-shadow).
Fred
<observational-astronomy><betelgeuse><occultation><observation-campaign>
What can be learned by observing tumbling asteroid 319 Leona passing in front of Betelgeuse's fickle photocenter? What campaigns have been organized?
uhoh
# What can be learned by observing tumbling asteroid 319 Leona passing in front of Betelgeuse's fickle photocenter? What campaigns have been organized?

(Asked by: username_0 on 2023-12-07)

There's a lot of interest in [Betelgeuse](https://en.wikipedia.org/wiki/Betelgeuse) party because of it's recent fainting behavior, and despite being so close, the huge uncertainty in it's distance due to its fickle photocenter:

* [Can New Horizons be used to measure the distance to Betelgeuse (despite its fickle photocenter)?](https://astronomy.stackexchange.com/q/39427/7982)
* [What will it finally take to accurately measure the distance to Betelgeuse?](https://astronomy.stackexchange.com/q/36365/7982)
* [Did the late 2019 "fainting" of Betelgeuse show any spectral trends that differ from it's normal variability?](https://astronomy.stackexchange.com/q/34545/7982)
* [Why does titanium oxide around Betelgeuse produce this particular sawtooth-shaped absorption spectrum?](https://astronomy.stackexchange.com/q/35451/7982)
* [When we say a variable star is "fainting" does it mean something more or different than "dimming" or "fading"?](https://astronomy.stackexchange.com/q/34547/7982)

Soon the asteroid [319 Leona](https://en.wikipedia.org/wiki/319_Leona) will pass in front of Betelgeuse.

* <https://cloud.occultwatcher.net/event/1075-319-83995-648466-H27989#>

**Question:** Is this occultation a rare and valuable opportunity to learn things about Betelgeuse itself and whatever might be around it (e.g. dust rings, etc.)? If so, what's been organized to maximize the granularity and diversity of measurements?

**Tags:** observational-astronomy, betelgeuse, occultation, observation-campaign

> **Comments:**
> **username_1**: FWIW, 319 Leona has been in retrograde motion since early November and will resume prograde motion in early February. Here's a geocentric plot of its J2000 ecliptic longitude & latitude, using a 2 day timestep https://i.sstatic.net/XhHoT.png (with numeric labels every 30 days)  
> **username_0**: @username_1 *Beautiful!* I'll bet you can add Betelgeuse's trajectory fairly easily (hint hint) :-)  
> **username_1**: The ecliptic coords of Betelgeuse are lon 88.755, lat -16.027. That plot is from the centre of the Earth, so it's of limited use in determining the exact time of occultation. I only posted it to give a rough idea of how 319 Leona is currently moving.  
> **username_0**: @username_1 ya, Betelgeuse has a substantial parallax, but at this scale its motion is invisible and the intersection with Earth's surface (rather than center) even "invisibler", but I feel better seeing the dot anyway https://i.sstatic.net/ji9cq.png  
> **username_2**: Discussed on Phil Plaits newsletter https://badastronomy.substack.com/p/big-body-briefly-blocks-betelgeuse  
> **username_3**: Something similar happened in [2022 regarding Pluto](https://www.abc.net.au/news/2022-06-12/nasa-scientists-in-australian-outback-searching-for-pluto/101130096) to get a "weather report" for Pluto. Apparently Mike Skrutskie of U Virginia is a seasoned occultation observer, and does events like this a couple of times a week at home, “but mostly asteroids”. Apparently it is how the [rings or Uranus & Neptune were found](https://spaceaustralia.com/news/northern-territory-rural-students-observe-plutos-shadow).  

---

## 2 answers

### Answer by username_4 on 2023-12-12. Score: 4

Unfortunately, I have not found much information. On the website of the "*Societé Astronomique de France*" they say:

*A team of researchers from Paris Observatory – PSL under the direction of Dr. Miguel Montargès (author of the study published in Nature, "*A dusty veil shading Betelgeuse during its Great Dimming*") is mobilizing the amateur astronomer community **to acquire photometric and spectroscopic data** on this occasion.
The collected data will be used **to characterize Betelgeuse’s photosphere in the visible and, potentially, to reconstruct its image and the velocity distribution of the convective cells***.

Ref. [**Occultation of Betelgeuse by asteroid (319) Leona on 12/12/2023 – Press release**](https://saf-astronomie.fr/loccultation-de-betelgeuse-par-lasteroide-319-leona-le-12-decembre-2023/)

I also found: *Asteroidal occultations of stars are frequent phenomena but the occultation of Betelgeuse by Leona will be extremely important and unique. It represents an extraordinary opportunity **to analyze the diameter and brightness distribution of Betelgeuse’s photosphere** by studying the light curve as the asteroid progressively occults the star from different points on Earth and at different wavelengths. In the overwhelming majority of the stellar occultations the diameters of the stars are tiny compared to the angular size of the solar system body that passes in front of them so the occultations are not gradual, but in this case, the huge angular diameter of Betelgeuse will give rise to a different phenomenon of “partial eclipse” and “total eclipse” (provided that Leona’s angular diameter is large enough compared with that of Betelgeuse)*.

Ref. [**The stellar occultation by (319) Leona on 13 September 2023 in preparation for the occultation of Betelgeuse**](https://arxiv.org/abs/2309.12272)

The "International Occultation Timing Association / European Section e.V." made a [**Call for Observations: Occultation of Betelgeuse by (319) Leona on 2023 Dec 12**](https://www.iota-es.de/betelgeuse2023.html)

And they have published on their website a follow-up of the occultation: [**News Feed – Occultation of Betelgeuse by (319) Leona**](https://call4obs.iota-es.de/news-feed-occultation-of-betelgeuse-by-319-leona)

This Spanish website invites amateur astronomers to make observations of the occultation: [**La ocultación de Betelgeuse del 12 de diciembre de 2023**](https://starblink.org/ocultacion_betelgeuse)

The dimming of Betelgeuse due to the occultation, captured by an amateur in Spain this past night, can be seen here, (Betelgeuse is the bright star at the top, a little to the left).

[**Occultation of Betelgeuse (Betelgeuze) by 319 Leona** (Jörg Schoppmeyer)](https://www.youtube.com/watch?v=KlIjVjqcnmE)

Best regards.

**UPDATED:** Light curves and videos of the occultation are being uploaded: [**Observations of the Occultation of Betelgeuse by (319) Leona (IOTA/ES)**](https://call4obs.iota-es.de/observations-of-the-occultation-of-betelgeuse-by-319-leona)


---

### Answer by username_5 on 2023-12-10. Score: 0

On <https://www.virtualtelescope.eu/webtv/>, Gianluca Masi, the Italian astronomer and developer of "THE VIRTUAL TELESCOPE PROJECT", has posted the following announcement :

> Next event: “Betelgeuse occultation by Leona: live view” – 12 Dec. 2023, starting at 01:00 UTC

The Virual Telescope Project uses multiple robotic telescopes to perform observations.

More details here: <https://www.virtualtelescope.eu/2023/12/04/the-extremely-rare-betelgeuse-occultation-by-asteroid-319-leona-online-event-12-dec-2023/>

> **Comments:**
> **username_6**: That's interesting to know - but it misses at least half the #question of "what can be learned" or "what do they expect to learn" (however the question title is broader than explained in the question...)  
> **username_0**: I think this is for entertainment purposes for the public to watch, rather than for astronomical measurements. I would not call this a real astronomical observation campaign.  

---

