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Astrerisms from the outside.

Posted: 30.04.2019, 15:33
by Janus
Has anyone besides me wondered what star signs like the the big and little dipper look like from elsewhere?
Or to put it another way, how narrow is our view of the universe from our lonely little rock.
Here is one view you might find interesting then.

Outside Of Asterisms.png

This is all of the asterisms as seen from quite a distance away.
Not nearly so neat looking or orderly from out there are they?

If you want to look things over for yourself, here.
(2.74 MiB) Downloaded 119 times

This is commit 5471 modified to keep asterisms bright and visible.
It also has RaDecDist visibility as well.

I roughly doubled the asterisms color and added some red, I dislike the original color anyway.
I then altered the visibility measure to keep them showing from a long ways away.
The purpose is to show how stars that look close or adjacent to us here, may not really be.

I hope others find this as amusing as I do.


Posted: 30.04.2019, 16:03
by pirogronian
Long time ago I made short video about this :smile: This is one of reasons why I love Celestia so much.
(but without English translation)

Posted: 30.04.2019, 23:12
by Lafuente_Astronomy
Well, I did ask for a proposition to allow asterism.dat files for planetary bodies

That was during the time I discovered that I can manipulate the asterisms.dat file, and made my own corrections to certain constellations, especially Ursa Major, since I feel that the Big Dipper is merely an asterism, and if Ursa Major is represented by th Big Dipper, than it lacks a lot

I specifically asked for asterisms.dat file for other planets in regards to Alpha Centauri. Since there are some big changes in the sky when we go to Alpha Centauri

Added after 7 minutes 1 second:
The most obvious example is here: Sirius is located near Betelgeuse, giving us a bright double-star view, and giving Orion 2 armpits, if that's the case here
Orion as seen from Proxima Centauri.jpg

Posted: 30.04.2019, 23:23
by Janus

Can you duplicate the view using the more visible version I posted.
I do not recognize what you mean, and no lines are visible to show me what you mean.
I don't know or use asterisms much except for the modified ones I use for charting interstellar journeys.


Posted: 30.04.2019, 23:33
by Lafuente_Astronomy
There you go:
Orion as seen from Proxima Centauri(With lines).jpg

Posted: 01.05.2019, 08:55
by onetwothree
Lafuente_Astronomy wrote:I specifically asked for asterisms.dat file for other planets in regards to Alpha Centauri. Since there are some big changes in the sky when we go to Alpha Centauri

I wish I were on Alpha Centauri's planets to draw constellations from there :)

Posted: 01.05.2019, 13:23
by Lafuente_Astronomy
onetwothree wrote:I wish I were on Alpha Centauri's planets to draw constellations from there

Well, at least with Celestia, provided you devs can find a way to allow multiple asterisms.dat files, or a single massive asterisms.dat file that comprises all asterisms of all possible star constellations as seen from other planets, and it also comes with their own grids, then it can be done.

I asked that exact question a month ago. It's somewhere in the "Celestia 1.7.0 Development Thread" post, I can mention it here if you want. I know that it's not necessary, as no credible scientist in Astronomy has ever done such a thing. But even if it's just for fun, I feel that contributions to the Astronomical Research can be done through the drawing of asterisms and constellations as seen from exoplanets, especially potentially habitable ones, as it could mark potential spots for spotting more objects for Astronomy, and the like. It could mark possible areas to scan from in the event we can land on such exoplanets and put our instruments there, just as we divided the sky into 88 different pieces(Actually 89, as Serpens is divided into 2 pieces) to specify and mark our astronomical discoveries. Because while out view of space from the Earth is immensely impressive, it can be further widened and expanded if we can, in the far, far future, carry our highly advanced instruments and put them on such planets to expand our view of the entire Universe, finite or infinite.

Hence, if the feasibility of such a program is possible, then perhaps it should be done, so that we can spark in the minds of many, an initiative to draw constellations for exoplanets, and thus contribute an imaginative aspect to Astronomy. While the existence of such things as galaxies, nebulae and stars are amazing in their own right, perhaps drawing figures in the skies has been the oldest use of imagination with regards to the sky.

All I'm saying is: If you can, and want, please allow a modification of the asterisms.dat file to allow the drawing of asterisms as seen from other planets. Our contributions would be very fantastic indeed.

Posted: 01.05.2019, 13:49
by Janus
I actually figured a couple of ways to do the multiple asterisms thing a while back.

First you need the multiple files.
Second, you need to list them in celestia.cfg as an array like catalogs are.

Then you either read the files when you issue a celx order. {Not recommended, just possible}
Or you read them all into memory as an array of asterisms.
The latter also allows for script created asterisms on the fly by adding a few celx calls, which can then be selected.

All you need to do is add something like this. {Warning, I am not a real C/C++ programmer.}

uint8_t asterismlistcount
uint8_t asterismactive
std::array<asterisms> masterasterismlist

I probably have that wrong, no time to look it up right now.
But it is intended to be an array of asterisms.
You then point asterisms to masterasterismlist[index]
set asterisms::prepared = 0/false
Since asterisms is a pointer, just change what it points to.
To change the displayed asterism list.
Been to distracted by greeking and other noise to study how to implement.


P.S. Someone please tell me there will be a way to turn all the greek letters off, they are incredibly annoying for me.
Perhaps a setting in the cfg, hint.

Posted: 01.05.2019, 14:41
by Lafuente_Astronomy
That can do, but perhaps let us listen to what the devs have to say about that first, then we can start. They might also offer improvements that could fulfill the purpose of our objectives, that is to allow asterisms in other planets, especially exoplanets