orientation of galactic coordinate system centered at Earth's sun, looking from Earth's perspective? Ouch my brain exploded!
Ultrus
to work out. I managed to plot stars in a sky looking from the Sun's
position, and can make out constellations seen from our sky. Now if I
virtually move to the Earth's position, and look at the sun, how will
the galactic sphere of stars rotate?
My current project can be seen at: www.christopherstevens.cc/fun
To get started, star locations were calculated from the Yale Bright
Star Catalog, with datasets obtained from:
http://terpsichore.stsci.edu/~summers/viz/datasets/datasets.html .
Basic information regarding the galactic coordinate system can be
found at: http://en.wikipedia.org/wiki/Galactic_coordinate_system . I
also saw a cool youTube video showing a changing orientation of the
galactic equator at: http://www.youtube.com/watch?v=I0HEgGbY-kw .
Any thoughts on where to get started? I could probably do without the
stars in this simulation toy, but since I already went through the
trouble, I feel it would be a waste to do so. I appreciate any
feedback you could give. I also much appreciate it if you could spell
things out as much as you can stand as my mind is more artistically
oriented then mathematically inclined. :P
Thank you much!
Chris
Raphanus
> I'm making an Earth simulator in Flash and still have several concepts
> to work out. I managed to plot stars in a sky looking from the Sun's
> position, and can make out constellations seen from our sky. Now if I
> virtually move to the Earth's position, and look at the sun, how will
> the galactic sphere of stars rotate?
>
> My current project can be seen at:www.christopherstevens.cc/fun
>
> To get started, star locations were calculated from the Yale Bright
> Star Catalog, with datasets obtained from:http://terpsichore.stsci.edu/~summers/viz/datasets/datasets.html.
> Basic information regarding the galactic coordinate system can be
> also saw a cool youTube video showing a changing orientation of the
> galactic equator at:http://www.youtube.com/watch?v=I0HEgGbY-kw.
>
> Any thoughts on where to get started? I could probably do without the
> stars in this simulation toy, but since I already went through the
> trouble, I feel it would be a waste to do so. I appreciate any
> feedback you could give. I also much appreciate it if you could spell
> things out as much as you can stand as my mind is more artistically
> oriented then mathematically inclined. :P
>
> Thank you much!
>
> Chris
The effects will be extremely small because the distance to the stars
is much greater than the sun-earth distance. If one looks at the sky
now and wait a half-year (we're now on the other side of the sun) one
can't tell any difference without scientific instruments. I don't
think there is any use in trying to be precise. Fake it. Have them
move a small - barely perceptible amount in an direction opposite to
the direction of motion.
Ultrus
Raphanus,
Good point and great idea! That will work well for this project. I
guess the biggest issue on faking it right now is the current
orientation around the sun. The big dipper (seen in orange in my
project) looks upside down, where in our sky in the US it looks right
side up. Of course everything looks different standing on the Earth's
surface. I'm looking for ways to verify which way is up, down, etc. in
the star sphere so that the stars are in the somewhat correct
directions. It is very possible that my calculations may have inverted
where things really should be, or rotated everything 90 or more
degrees, etc.
Raphanus
> > Fake it. Have them move a small - barely perceptible amount in an direction opposite to the direction of motion.
>
> Raphanus,
> Good point and great idea! That will work well for this project. I
> guess the biggest issue on faking it right now is the current
> orientation around the sun. The big dipper (seen in orange in my
> project) looks upside down, where in our sky in the US it looks right
> side up.
Believe me - the big dipper doesn't move just because the observer
moves from the sun to the earth. I have seen the big dipper appear to
be upside down. It depends on the time of night and the season.
Of course everything looks different standing on the Earth's
> surface. I'm looking for ways to verify which way is up, down, etc. in
> the star sphere so that the stars are in the somewhat correct
> directions. It is very possible that my calculations may have inverted
> where things really should be, or rotated everything 90 or more
> degrees, etc.
Remember that a reference frame doesn't dictate in which direction the
oberver is looking - only where the observer is located. The earth's
surface is a moving reference frame.
My impression is that you may have more thinking to do about what
you're trying to accomplish.
The star Polaris could be "the star" of your show.
Good luck.
Ultrus
Raphanus,
Thanks again for your feedback. I understand what your saying and
apologize if my words aren't making much sense. Let me show you a
draft:
http://www.christopherstevens.cc/fun/test2.htm
The stars don't "move" themselves, but they do move on the screen as I
rotate about the Earth. The star locations will never physically
change in this project. I hope that helps clarify. You can see the
potential in the link I sent, but calculating or faking what direction
the sun is in relation to the Earth (I can figure this part out), and
galactic angle of the galactic star shpere in relation to this project
scene, makes my left eye fall out of the socket.
One point that bugs me is Polaris. Polaris is highlighted in orange,
just "south" of the Big Dipper. To me it seems to be an odd location
for a "north star", even if the the Earth's surface is a moving
reference frame. That's when I started seeking calculations that might
put the sun and earth into perspective with the rest of the galaxy,
rotating the star sphere to fit the scene anyway. After some sleep
though it may come together. If you hold apple/ctrl+click and drag,
you'll see the "star sphere" or backdrop I speak of.
Thanks much for your input. I look forward to any additional thoughts
out there. :)