Talk:Fish Head Nebula

Miscredited Photo

New to wikipedia, so sorry if this is the wrong way of going about this.

However I noticed that the main photo of the Fish Head Nebula is credited to the Hubble Space Telescope, but has a watermark to "Carsten Frenzl" and appears to have been taken and processed by them, according to the image description. SharablePeak (talk) 17:35, 11 January 2025 (UTC)

 Done Thank you @SharablePeak, for letting us know. I fixed the caption. jengod (talk) 17:50, 11 January 2025 (UTC)

Wow that was fast, thanks SharablePeak (talk) 18:04, 11 January 2025 (UTC)

Duplicate

I think this article should be merged with Westerhout 3. If others agree, I can do that. (Not much work, because there isn’t much content) Tk833 (talk) 13:10, 25 November 2025 (UTC)

W3 is a molecular cloud. This is about a nebula within W3. ^EF⁵ 13:18, 25 November 2025 (UTC)

W3 is a radio source. Radio astronomer Westerhout detected 3 peaks in that region: W3, W4, and W5. At their positions, we see three nebulae: Fish Head Nebula, Heart Nebula, and Soul Nebula. W3 corresponds to (the HII region) Fish Head Nebula. Tk833 (talk) 14:37, 25 November 2025 (UTC)

Is there a source that backs this up? ^EF⁵ 14:41, 25 November 2025 (UTC)

Just compare the positions of the radio source (see Bibcode 1958BAN....14..215W) with the position of the Fish head Nebula. Westerhout 3 article says: "...corresponds specifically to the bright emission nebula Fish Head Nebula (IC 1795)..." .

Let me turn the question around: What source justifies the claim that the Fish Head Nebula is a separate object? The article refers only to other websites and SIMBAD doesn't even know a Fish Head Nebula.

But anyway, I can live with the current situation. Tk833 (talk) 15:25, 25 November 2025 (UTC)

The Fish Head Nebula is IC 1795, which is recognized here. I'm not seeing any sources that directly correlate W3 to this nebula which is why I don't think they should be merged. This publication notes that IC 1795 is in W3, not that they are the same thing or a duplicate designation. ^EF⁵ 15:37, 25 November 2025 (UTC)

I see no contradiction: W3 was detected as a radio peak in 1958 (see the reference above). Later, with better instruments, an extended structure could be seen. (Typically still designated W3 because this was the initial detection. In SIMBAD, W3 is still a point source.) Nowadays, with help of accurate distance measurements from Gaia, we know that W4 and W3 belong together. Furthermore, the Sharpless 2 designation for both the Heart Nebula and the Fish Head Nebula is SH2-190.

However, if you want to keep the article Fish Head Nebula, you should at least properly refer to the parent structures and support this with references (not just web pages). Currently, the article contains no non-trivial information that cannot be found in the W3 article, and all its references are webpages (Two amateur homepages and one link to a internet forum). Tk833 (talk) 17:15, 25 November 2025 (UTC)

We'll agree-to-disagree because I'm really not wanting to argue over this. ^EF⁵ 17:17, 25 November 2025 (UTC)

I disagree to disagree, because I do agree that the Fish Head Nebula can be seen as part of a larger structure (W3 / W3+W4 / SH2-190 / ...), as noted in my previous message. (As pointed out above, there are no exact definitions of what these designations precisely describe. This also varies over time and from author to author.)

Since I feel no urgent need to merge, I replaced the duplicate warning with a nebula-stub template. (I still think merging would have been the easier way to address the issues mentioned in my previous message.) Tk833 (talk) 19:46, 25 November 2025 (UTC)