[Chinese & Modern Chinese skycultures] Potential incorrect constellation lines for 牛宿 (Ox Mansion)

[lethefrost]

I noticed that in the Chinese and Modern Chinese skycultures (chinese & modern_chinese), the constellation lines for 牛宿 (Ox Mansion) differ from several historical sources I have consulted. Specifically, I’ve observed:

• Missing connections in Stellarium (present in historical sources):
  • 牛宿三 (ξ² Cap) - 牛宿一 (β¹ Cap)
  • 牛宿一 (β¹ Cap) - 牛宿六 (ρ Cap)
• Additional connections in Stellarium (not present in the historical sources):
  • 牛宿二 (α² Cap) - 牛宿三 (ξ² Cap)
  • 牛宿六 (ρ Cap) - 牛宿四 (π Cap)

Current	Expected

These line patterns are derived from those references:

• Dunhuang Star Chart (《敦煌星图》), ~700 AD (Tang Dynasty)
• Tongzhan Daxiangli Xingjing (《通占大象历星经》), Tang Dynasty
• Xinyi Xiangfayao (《新仪象法要》), ~1100 AD (Song Dynasty) by Su Song—Among the various versions of this text that are accessible today (some being transcriptions or later copies), certain editions show no constellation lines at all, and some are missing the line between 牛宿一 (β¹ Cap) and 牛宿六 (ρ Cap)—See the third screenshot. It’s unclear whether these omissions are due to scanning limitations or loss during manual copying over time. However, the version from which I’ve attached in the first and second screenshots does include this line, and matches the other references listed here.
• Chunyou Tianwen Tu (《淳祐天文图》), or carved version Suzhou star cartography (苏州石刻天文图), ~1200 AD (Song Dynasty) by Huang Shang
• A modern SVG star map (source unknown, assistance appreciated for attribution)
• Even the included reference image "Astronomical Map of Complete Studies of Astronomy (1757)" in the chinese culture matches the historical sources described above.

I am unsure if it is an unintended error. Perhaps these differences are based on alternative sources or variations I am not aware of, or they might represent intentional design decisions made during the original creation of these skyculture files. @sunshuwei

I welcome any corrections or explanations and would appreciate learning about any other relevant references or the rationale behind these constellation-line decisions. If it turns out this discrepancy is indeed an error rather than an intentional design, I'd be happy to contribute a pull request to help correct it—please feel free to let me know.

Stellarium Version: 25.1.0

Operating System: macOS 15.4.1

Thank you very much for your attention, and for your wonderful efforts on Stellarium!

[sushoff]

First quick answer: Well, the constellation do change over the course of centuries. We attempt to show this, in particular please compare the "Chinese Chenzhuo" and the "Chinese Medieval" sky culture: these two SCs are historically correct. You must not mix different maps/ star catalogues.

"Modern Chinese" are the IAU-constellations with Chinese star names and other adoptions, so this is not at all historical, and "Chinese" without specifyer is a generalization & didactical reduction by Hong Kong Space Museum... it is also not historically correct. You must not compare it to the Dunhuang, Suzhou or Su Song Map ...

I don't think that it makes sense to have all the hundreds of flavours of the traditional Chinese (likewise: the Almagest) tradition in Stellarium, but to be historically correct, we should do so. Therefore, I am currently attempting to develop another system - an encyclopaedia where these confusions are resolved/ explained ... and ideally (if I get further funding) an interactive star chart with all the historical documents directly mapped would be displayed. - Unfortunately, during the past ~5 years most of my research proposals that aimed at this development have been rejected. What I am currently funded for is at least setting up the repository of the data collection.

Second, the Stellarium Team currently reorganizes the sky culture specification, so we may restructure this sort of information here, too.

Third, for the specific issue of missing line, I suggest that @sunshuwei with Yang Boshun and me think about a solution (not all of us are on Github, which slows down the communication.

[sushoff]

There are several mistakes in the "Chinese Modern" sky culture. Boshun had told me some time ago.

1. For the Ox mansion, we recommend to follow the old tradition (same as the Chenzhuo and Song version).

2. Boshun made changes to a few constellations. Here is his list:

   "HIP 19167": [{"english": "Stored Water", "native": "积水[天船]", "pronounce": "Jishui"}],

   "id": "CON chinese_chenzhuo 23G",

   "lines": [[39429, 43023, 39953], [43023, 44511, 44816], [44511, 47175]],

   "common_name": {"english": "Celestial Earth God's Temple", "native": "天社", "pronounce": "Tian She"}

   "id": "CON chinese_chenzhuo 01J",

   "lines": [[68702, 71683],

   "common_name": {"english": "Southern Gate", "native": "南门", "pronounce": "Nan Men"}

   "id": "CON chinese_chenzhuo 26B",

   "lines": [[48374, 46651, 48926, 48748, 53699, 53502, 53773, 51986, 50609, 51561, 50799, 50191, 50241, 49485, 48374]],

   "common_name": {"english": "Celestial Temple", "native": "天庙", "pronounce": "Tian Miao"}

   "id": "CON chinese_chenzhuo 28H",

   "lines": [[51523, 52154, 52742, 53154, 54463, 56243, 59747, 60379, 61084], [60781, 57439, 54751, 53253, 51849, 51140], [50555, 50676, 51192, 51232, 52102, 52468, 54301, 56561, 60260, 62434], [50371, 51576, 52419, 57669, 58758, 60009, 60718]],

   "common_name": {"english": "House for Musical Instruments", "native": "器府", "pronounce": "Qi Fu"}

3. I will update the JSON-file

[lethefrost]

Thank you so much for the following up and clarification! I appreciate your work and time.

[alex-w]

Boshun’s fix in commit 26d92d6d6eab04b1a7de711826fe037d8db9a2fd

[sushoff]

@lethefrost I don't dare to touch the "Modern (Chinese)" and the "Chinese" (Without specification), as both seem to me a bit ...well,... artificial. They are not based on any specific historical map. They are meant to reflect "pop-culture", and as such - in my view - don't try to immitate any of them specifically.

On behalf of Stellarium, all astral researchers, I thank @sunshuwei and Yang Boshun for their contributions of the historical maps of the Han- and Song-Dynasty. Hence, I would like to encourage you to do something similar for the Suzhou Map and Dun Huang Map - that would be really great, specifically as this one is so famous! If you think, "Chinese" already matches it to a good extend, it may even ease your work, as you can copy it to your own branch and just vary what you think needs to be different (e.g. the lines in the Ox constellation).

However, this issue I would close now:

• as I said, the SCs you mentioned are not meant to show any historical accuracy
• we added some fixes in the accurate Chinese SC

If you do a "Chinese (Dun Huang)" or "Chinese (Suzhou)", we will open a new issues for that -> ok?

[lethefrost]

@lethefrost I don't dare to touch the "Modern (Chinese)" and the "Chinese" (Without specification), as both seem to me a bit ...well,... artificial. They are not based on any specific historical map. They are meant to reflect "pop-culture", and as such - in my view - don't try to immitate any of them specifically.

On behalf of Stellarium, all astral researchers, I thank @sunshuwei and Yang Boshun for their contributions of the historical maps of the Han- and Song-Dynasty. Hence, I would like to encourage you to do something similar for the Suzhou Map and Dun Huang Map - that would be really great, specifically as this one is so famous! If you think, "Chinese" already matches it to a good extend, it may even ease your work, as you can copy it to your own branch and just vary what you think needs to be different (e.g. the lines in the Ox constellation).

However, this issue I would close now:

• as I said, the SCs you mentioned are not meant to show any historical accuracy
• we added some fixes in the accurate Chinese SC

If you do a "Chinese (Dun Huang)" or "Chinese (Suzhou)", we will open a new issues for that -> ok?

Hi @sushoff , thanks for the clarification. I'd actually be interested in helping with researching historical sources and contributing a skyculture in the future. At the moment I'm a bit busy though—is this something without a strict deadline, or not urgent? Also, if I run into questions along the way, who would be the right person to ask, and which platform do you usually use for communication?

[sushoff]

Our platform is GitHub, as you know.

There is definitely no deadline. Actually, I recommend to wait with new contributions a bit, as a student team has just developed a new "sky culture maker" that looks promissing but needs to be tested (and perhaps improved). Then, with that, it will be really easy to contribute new sky cultures.

[lethefrost]

Our platform is GitHub, as you know.

There is definitely no deadline. Actually, I recommend to wait with new contributions a bit, as a student team has just developed a new "sky culture maker" that looks promissing but needs to be tested (and perhaps improved). Then, with that, it will be really easy to contribute new sky cultures.

Sounds wonderful and thanks for telling me about it! Looking forward to trying out the cool tool after a while ☺️

[gzotti]

1. For the Ox mansion, we recommend to follow the old tradition (same as the Chenzhuo and Song version).

Can we apply this now please? If we all agree that the current version from a lost modern map is "bad", please apply the well-known historical lines for the Ox.

[sunshuwei]

This is indeed an error. My apologies—I was busy and did not see this issue for a long time.

[sushoff]

This is indeed an error. My apologies—I was busy and did not see this issue for a long time.

[sushoff]

1. For the Ox mansion, we recommend to follow the old tradition (same as the Chenzhuo and Song version).

Can we apply this now please? If we all agree that the current version from a lost modern map is "bad", please apply the well-known historical lines for the Ox.

Both SCs concerned are Digitalis contributions, but we may rework it (CC allows) - Sun Shuwei has done so in the past, so @sunshuwei please keep editing it

[sunshuwei]

1. For the Ox mansion, we recommend to follow the old tradition (same as the Chenzhuo and Song version).

Can we apply this now please? If we all agree that the current version from a lost modern map is "bad", please apply the well-known historical lines for the Ox.

Both SCs concerned are Digitalis contributions, but we may rework it (CC allows) - Sun Shuwei has done so in the past, so @sunshuwei please keep editing it

OK

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Hello @lethefrost!

Please check the fresh version (development snapshot) of Stellarium: https://github.com/Stellarium/stellarium-data/releases/tag/weekly-snapshot

[github-actions[bot]]

Hello @lethefrost!

Please check the latest stable version of Stellarium: https://github.com/Stellarium/stellarium/releases/latest