<p>The blue line in the first image is the Galatic equator, the line that runs through the middle of the Milky Way.  It isn't the ecliptic*.  M36,M37 and M38 are star clusters, and tend to be near the galactic equator.</p>
<p>The ecliptic follows the apparent path of the sun and, as you might expect, it follows the zodiacal constellations.  The orange line in the second image is the ecliptic.</p>
<p>*<sub>It seems in very early versions, prior to Nov 2013, both lines were drawn, by April 2014, the ecliptic line had been removed, and until Oct 21st 2020 only the galactic equator was drawn. This was inconsistent with the other constellation maps.  From   November 2020, new high resolution images were prepared and these had the ecliptic drawn, not the galactic equator.  It seems likely that this was a result of human error.</sub></p>

CC BY-SA 4.0
2024-08-10T20:55:32.023Z
Thanks for the answer. So in the past, they drawed the galactic equator with the colors of the ecliptic path, as I can see, since I have the original image downloaded the day 2019/12/30. Looking the stats of this image, it was generated the day 2013/12/06.
Unix
CC BY-SA 4.0
2024-08-10T21:48:23.067Z
I've had a browse around, There are various versions of the constellation maps.  Some have just the ecliptic, Many have both the ecliptic and the galactic equator drawn. The version on "galactic-hunter.com" has only galactic equator. There is no standard "colour of the ecliptic path".  There are lots of possible lines that could be drawn in the sky: the equator, the ecliptic and the galactic equator are the three most common. You can't assume it is meant to be the ecliptic from the colour.
James K
CC BY-SA 4.0
2024-08-10T22:09:45.607Z
Well, in the version I have, there's only one blue line corresponding to the ecliptic (labeled when there's space enough), and only one chart where this line is the galactic line. So it's a mistake in my opinion, because it appears only in 1 chart of 89, being the ecliptic path in the others (whent it's visible). Actually, they fixed it, drawing the ecliptic with the same color and removing the galactic line at the same time.
Unix
CC BY-SA 4.0
2024-08-10T22:18:39.093Z
Actually, I assumed that by the context. Keep in mind that they generated these charts with a software like the one I'm using to generate my charts: plotting astronomical data through algorithms (Python, in my case). How only one chart ended up with the galactic line instead of the ecliptic is a mistery.
Unix
CC BY-SA 4.0
2024-08-10T22:21:52.087Z
You know, I think you're right.  Looking at the wayback machine versions,  Auriga seems to be the only one with the galactic equator drawn, and not the ecliptic.  So it probably was a mistake from back then
James K
CC BY-SA 4.0
2024-08-10T20:40:58.640Z
2024-08-10T22:32:06.197Z
2024-08-10T22:32:06.197Z
James K
<p>I'm making some sky charts using astropy and matplotlib (in Python), and I've just discovered that the ecliptic from the sky charts created by the IAU and Sky&amp;Telescope could be wrong. This is in Auriga constellation. Look at this:</p>
<p><a href="https://i.sstatic.net/pzEP6sfg.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/pzEP6sfg.gif" alt="enter image description here" /></a></p>
<p>The image I'm producing in my computer is the next one. I'm gonna target the M36 object, to see the same area, approximately. This is my image:</p>
<p><a href="https://i.sstatic.net/23a4bLM6.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/23a4bLM6.png" alt="enter image description here" /></a></p>
<p>See? In my case, ecliptic path is totally different. I'm using J2000 equinox. I've checked other software (kstars, skychart and stellarium) and they are like mine. Do they have a big mistake in the official IAU charts?</p>

CC BY-SA 4.0
2024-08-10T20:48:08.890Z
Can you please give the **exact** source of the first image.  The image on the iau  website is different https://www.iau.org/public/themes/constellations/
James K
CC BY-SA 4.0
2024-08-10T20:51:22.850Z
Oh I see. I downloaded this image 4 years ago! It's the same source. I'm glad that they corrected it. Thanks!!
Unix
<ecliptic>
Is the ecliptic path correct in this sky chart?
Unix
# Is the ecliptic path correct in this sky chart?

(Asked by: username_0 on 2024-08-10)

I'm making some sky charts using astropy and matplotlib (in Python), and I've just discovered that the ecliptic from the sky charts created by the IAU and Sky&Telescope could be wrong. This is in Auriga constellation. Look at this:

[![enter image description here](https://i.sstatic.net/pzEP6sfg.gif)](https://i.sstatic.net/pzEP6sfg.gif)

The image I'm producing in my computer is the next one. I'm gonna target the M36 object, to see the same area, approximately. This is my image:

[![enter image description here](https://i.sstatic.net/23a4bLM6.png)](https://i.sstatic.net/23a4bLM6.png)

See? In my case, ecliptic path is totally different. I'm using J2000 equinox. I've checked other software (kstars, skychart and stellarium) and they are like mine. Do they have a big mistake in the official IAU charts?

**Tags:** ecliptic

> **Comments:**
> **username_1**: Can you please give the **exact** source of the first image.  The image on the iau  website is different https://www.iau.org/public/themes/constellations/  
> **username_0**: Oh I see. I downloaded this image 4 years ago! It's the same source. I'm glad that they corrected it. Thanks!!  

---

## 1 answers

### Answer by username_1 on 2024-08-10. Score: 3 | Accepted answer

The blue line in the first image is the Galatic equator, the line that runs through the middle of the Milky Way. It isn't the ecliptic\*. M36,M37 and M38 are star clusters, and tend to be near the galactic equator.

The ecliptic follows the apparent path of the sun and, as you might expect, it follows the zodiacal constellations. The orange line in the second image is the ecliptic.

\*It seems in very early versions, prior to Nov 2013, both lines were drawn, by April 2014, the ecliptic line had been removed, and until Oct 21st 2020 only the galactic equator was drawn. This was inconsistent with the other constellation maps. From November 2020, new high resolution images were prepared and these had the ecliptic drawn, not the galactic equator. It seems likely that this was a result of human error.

> **Comments:**
> **username_0**: Thanks for the answer. So in the past, they drawed the galactic equator with the colors of the ecliptic path, as I can see, since I have the original image downloaded the day 2019/12/30. Looking the stats of this image, it was generated the day 2013/12/06.  
> **username_1**: I've had a browse around, There are various versions of the constellation maps.  Some have just the ecliptic, Many have both the ecliptic and the galactic equator drawn. The version on "galactic-hunter.com" has only galactic equator. There is no standard "colour of the ecliptic path".  There are lots of possible lines that could be drawn in the sky: the equator, the ecliptic and the galactic equator are the three most common. You can't assume it is meant to be the ecliptic from the colour.  
> **username_0**: Well, in the version I have, there's only one blue line corresponding to the ecliptic (labeled when there's space enough), and only one chart where this line is the galactic line. So it's a mistake in my opinion, because it appears only in 1 chart of 89, being the ecliptic path in the others (whent it's visible). Actually, they fixed it, drawing the ecliptic with the same color and removing the galactic line at the same time.  
> **username_0**: Actually, I assumed that by the context. Keep in mind that they generated these charts with a software like the one I'm using to generate my charts: plotting astronomical data through algorithms (Python, in my case). How only one chart ended up with the galactic line instead of the ecliptic is a mistery.  
> **username_1**: You know, I think you're right.  Looking at the wayback machine versions,  Auriga seems to be the only one with the galactic equator drawn, and not the ecliptic.  So it probably was a mistake from back then  

---

