<p>Though my computer is still crunching the numbers (and subsequently slowing everything else down... ) I can tell you the answer is no. It's up to the 1700s already (starting from 2 BC) and I've already seen multiple conjunctions in quite decent proximity of all three. I set the max to 5 degrees. I'm using a modified form of this python script.
<a href="http://shallowsky.com/blog/science/astro/predicting-conjunctions.html" rel="nofollow">http://shallowsky.com/blog/science/astro/predicting-conjunctions.html</a></p>

<p>Ok, the script has finished. I don't have it nicely filtered down to ONLY the conjunctions of all three, so I have 3000+ lines of results. I can copy a few instances in real quick though.</p>

<pre><code>Conjunction of Venus, Jupiter and Regulus lasts from 2015/6/23 to 2015/8/4.
Venus and Jupiter are closest on 2015/7/2 (0.4 deg).
Venus and Regulus are closest on 2015/7/16 (2.4 deg).
Jupiter and Regulus are closest on 2015/8/4 (1.8 deg).

Conjunction of Venus, Regulus and Jupiter lasts from 1885/7/25 to 1885/8/11.
Venus and Regulus are closest on 1885/7/29 (1.1 deg).
Venus and Jupiter are closest on 1885/8/7 (0.4 deg).

Conjunction of Jupiter, Regulus and Venus lasts from 1861/6/19 to 1861/8/6.
Jupiter and Regulus are closest on 1861/7/16 (0.5 deg).
Regulus and Venus are closest on 1861/7/30 (1.1 deg).
Jupiter and Venus are closest on 1861/8/2 (0.6 deg).

Conjunction of Venus, Jupiter and Regulus lasts from 1837/7/24 to 1837/8/3.
Venus and Jupiter are closest on 1837/7/28 (0.7 deg).
Venus and Regulus are closest on 1837/7/31 (1.2 deg).
Jupiter and Regulus are closest on 1837/7/31 (3.6 deg).

Conjunction of Venus, Regulus and Jupiter lasts from 1802/7/16 to 1802/8/1.
Venus and Regulus are closest on 1802/7/19 (1.1 deg).
Venus and Jupiter are closest on 1802/7/27 (0.5 deg).

Conjunction of Jupiter, Regulus and Venus lasts from 1778/6/12 to 1778/8/2.
Jupiter and Regulus are closest on 1778/7/11 (0.5 deg).
Regulus and Venus are closest on 1778/7/19 (1.2 deg).
Jupiter and Venus are closest on 1778/7/21 (0.6 deg).

Conjunction of Venus, Jupiter and Regulus lasts from 1754/7/12 to 1754/7/31.
Venus and Jupiter are closest on 1754/7/16 (0.8 deg).
Venus and Regulus are closest on 1754/7/21 (1.2 deg).
Jupiter and Regulus are closest on 1754/7/31 (2.5 deg).
</code></pre>

<p>You should probably verify these finds with a program like Stellerium.
Note that I set the view point to be in the middle east. Roughly where Persia used to be.</p>

CC BY-SA 3.0
2015-08-10T20:58:42.950Z
Are those conjunctions at a decent elevation (high enough in the sky) during evening or night? It's important to filter out conjunctions that are only visible during the day, or are too close the horizon (or below).
Florin Andrei
CC BY-SA 3.0
2015-08-11T11:27:50.317Z
This should be filtering out such conjunctions, yes. But of course, don't trust my script. Verify them as well separately.
AdamMasters
CC BY-SA 3.0
2015-08-10T20:05:33.603Z
2015-08-10T20:05:33.603Z
AdamMasters
<p>I recently heard the claim that mid-July, the "Star of Bethlehem" formed for the first time in 2,000 years, where the <a href="https://en.wikipedia.org/wiki/Star_of_Bethlehem#Planetary_conjunction">Star of Bethlehem</a> is a three-way conjunction between Venus, Jupiter, and Regulus. The Wikipedia page I just linked mentions one such conjunction occurring in 2 BC, and other sources (like <a href="http://earthsky.org/tonight/see-venusjupiter-conjunction-in-western-sky-after-sunset">EarthSky</a>) mention the conjunction that happened last month, in 2015 AD. Has this three-way conjunction never happened in the intervening 2016 years?</p>

<p>(For the purpose of this question, I'll say that it counts as a conjunction when each pair of bodies is separated by no more than 10 degrees, as suggested by this <a href="http://cosmoquest.org/forum/showthread.php?127683-Venus-Jupiter-Regulus-Conjuction">CosmoQuest forum thread</a> on the subject.)</p>

CC BY-SA 3.0
2015-08-01T19:52:07.163Z
Also, I would have added the tags [tag:regulus] and [tag:conjunction], but I don't have enough rep. Yet.
El'endia Starman
CC BY-SA 3.0
2015-08-06T20:05:12.577Z
Visible conjunctions preferred, but you could point out that non-visible conjunctions happen too.
El'endia Starman
CC BY-SA 3.0
2015-08-08T02:20:39.747Z
Hmm. Looking at the forum thread again, one person said that the maximum separation for all pairs was 5.5 degrees on July 16. So, perhaps that would be a better restriction?
El'endia Starman
CC BY-SA 3.0
2015-08-10T20:24:23.443Z
Yeah. 10 degrees is quite a bit, really.
AdamMasters
CC BY-SA 3.0
2015-08-10T21:01:29.307Z
The Moon is 0.5 degrees in diameter. Anything much bigger than that would not count as a very spectacular conjunction. A few degrees at most, let's say 5, but it would really have to be more like 2 degrees or 1 to look particularly interesting.
Florin Andrei
CC BY-SA 3.0
2015-08-11T15:06:07.360Z
The actual date was around June 29 or 30. Not mid July, just FYI.
AdamMasters
<jupiter><venus>
Has the conjunction between Venus, Jupiter, and Regulus only occurred twice in 2,000 years?
El'endia Starman
# Has the conjunction between Venus, Jupiter, and Regulus only occurred twice in 2,000 years?

(Asked by: username_0 on 2015-08-01)

I recently heard the claim that mid-July, the "Star of Bethlehem" formed for the first time in 2,000 years, where the [Star of Bethlehem](https://en.wikipedia.org/wiki/Star_of_Bethlehem#Planetary_conjunction) is a three-way conjunction between Venus, Jupiter, and Regulus. The Wikipedia page I just linked mentions one such conjunction occurring in 2 BC, and other sources (like [EarthSky](http://earthsky.org/tonight/see-venusjupiter-conjunction-in-western-sky-after-sunset)) mention the conjunction that happened last month, in 2015 AD. Has this three-way conjunction never happened in the intervening 2016 years?

(For the purpose of this question, I'll say that it counts as a conjunction when each pair of bodies is separated by no more than 10 degrees, as suggested by this [CosmoQuest forum thread](http://cosmoquest.org/forum/showthread.php?127683-Venus-Jupiter-Regulus-Conjuction) on the subject.)

**Tags:** jupiter, venus
> **Comments:**
> **username_0**: Also, I would have added the tags [tag:regulus] and [tag:conjunction], but I don't have enough rep. Yet.  
> **username_0**: Visible conjunctions preferred, but you could point out that non-visible conjunctions happen too.  
> **username_0**: Hmm. Looking at the forum thread again, one person said that the maximum separation for all pairs was 5.5 degrees on July 16. So, perhaps that would be a better restriction?  
> **username_1**: Yeah. 10 degrees is quite a bit, really.  
> **username_2**: The Moon is 0.5 degrees in diameter. Anything much bigger than that would not count as a very spectacular conjunction. A few degrees at most, let's say 5, but it would really have to be more like 2 degrees or 1 to look particularly interesting.  
> **username_1**: The actual date was around June 29 or 30. Not mid July, just FYI.  

---

## 1 answers

### Answer by username_1 on 2015-08-10. Score: 0

Though my computer is still crunching the numbers (and subsequently slowing everything else down... ) I can tell you the answer is no. It's up to the 1700s already (starting from 2 BC) and I've already seen multiple conjunctions in quite decent proximity of all three. I set the max to 5 degrees. I'm using a modified form of this python script.
http://shallowsky.com/blog/science/astro/predicting-conjunctions.html
Ok, the script has finished. I don't have it nicely filtered down to ONLY the conjunctions of all three, so I have 3000+ lines of results. I can copy a few instances in real quick though.
Conjunction of Venus, Jupiter and Regulus lasts from 2015/6/23 to 2015/8/4.
Venus and Jupiter are closest on 2015/7/2 (0.4 deg).
Venus and Regulus are closest on 2015/7/16 (2.4 deg).
Jupiter and Regulus are closest on 2015/8/4 (1.8 deg).

Conjunction of Venus, Regulus and Jupiter lasts from 1885/7/25 to 1885/8/11.
Venus and Regulus are closest on 1885/7/29 (1.1 deg).
Venus and Jupiter are closest on 1885/8/7 (0.4 deg).

Conjunction of Jupiter, Regulus and Venus lasts from 1861/6/19 to 1861/8/6.
Jupiter and Regulus are closest on 1861/7/16 (0.5 deg).
Regulus and Venus are closest on 1861/7/30 (1.1 deg).
Jupiter and Venus are closest on 1861/8/2 (0.6 deg).

Conjunction of Venus, Jupiter and Regulus lasts from 1837/7/24 to 1837/8/3.
Venus and Jupiter are closest on 1837/7/28 (0.7 deg).
Venus and Regulus are closest on 1837/7/31 (1.2 deg).
Jupiter and Regulus are closest on 1837/7/31 (3.6 deg).

Conjunction of Venus, Regulus and Jupiter lasts from 1802/7/16 to 1802/8/1.
Venus and Regulus are closest on 1802/7/19 (1.1 deg).
Venus and Jupiter are closest on 1802/7/27 (0.5 deg).

Conjunction of Jupiter, Regulus and Venus lasts from 1778/6/12 to 1778/8/2.
Jupiter and Regulus are closest on 1778/7/11 (0.5 deg).
Regulus and Venus are closest on 1778/7/19 (1.2 deg).
Jupiter and Venus are closest on 1778/7/21 (0.6 deg).

Conjunction of Venus, Jupiter and Regulus lasts from 1754/7/12 to 1754/7/31.
Venus and Jupiter are closest on 1754/7/16 (0.8 deg).
Venus and Regulus are closest on 1754/7/21 (1.2 deg).
Jupiter and Regulus are closest on 1754/7/31 (2.5 deg).

You should probably verify these finds with a program like Stellerium.
Note that I set the view point to be in the middle east. Roughly where Persia used to be.

> **Comments:**
> **username_2**: Are those conjunctions at a decent elevation (high enough in the sky) during evening or night? It's important to filter out conjunctions that are only visible during the day, or are too close the horizon (or below).  
> **username_1**: This should be filtering out such conjunctions, yes. But of course, don't trust my script. Verify them as well separately.  

---

