Astronomical Data

General discussion about Celestia that doesn't fit into other forums.
Topic author
Guest

Astronomical Data

Post #1by Guest » 20.09.2002, 03:39

Hello,

I downloade Celestia a few months ago, and found it quite fun for just playing around.

However, I have decided to focus my efforts on building a similar program for a school computer programming project. The project is heavily focused on databases, so such a database as the stars in our galaxy would be a nice choice so I am able to include graphics and 3d.

However, I have searched (on Google) for a basic database that lists bare minimun information (coordinates in space, star information like name, radius, type, colour, heat index (?)) to no avail. One small database I found included distance from Earth (I'm assuming), and some other variable (probably an angle of some sort). I could use this data, and translate it easily to x, y, z coordinates, but I don't know what this other variable is, or how I would use it.

My question is how the Celestia star database was collected. I opened stars.dat, which was a formatted file which I couldn't read.

If someone could please direct me to useful information, or provide a useful database, I would be quite grateful.

Rigel
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Post #2by Rigel » 20.09.2002, 07:27

I think it will take years of programming to get the same result than in Celestia ... Good luck !

The only catalog with accurate distances to stars in the Hipparcos catalog, from which the stars database of Celestia was initially computed. It contains about 100000 stars.

:wink:

Paul
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Post #3by Paul » 20.09.2002, 08:46

I use the following astro-search engine:

http://vizier.u-strasbg.fr/viz-bin/VizieR

Although it can take a little effort to get the catalogues you want, and the interface can be a little daunting, it is flexible enough to let you obtain just the minimum data you need. I highly recommend it.
Cheers,
Paul

Topic author
Guest

Post #4by Guest » 20.09.2002, 19:54

I'm not trying to make a program as impressive as Celestia, just one that has a star field that you can navigate, and withdraw information about the stars, etc.

Paul, that site is very useful, thank you.

However, it lists it's Position in some odd units. I'm assuming (I'm probably wrong) that it gives you the latitude and longtitude of a position on the earth, and if you were to extend a line from the center of the Earth in that particular direction for a specific distance, your star would appear there.

I highly doubt that this is how they give star postions.

I realize that I'm getting into something quite complicated here, but can anyone briefly explain how you go from those units to simple x, y, z? How was this done in Celestia, because I know that 0penGL uses that same coordinate system.

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selden
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Post #5by selden » 21.09.2002, 01:23

You might want to consider using one of the early databases of nearby stars. They're relatively small and, I think, easier to understand than the recent gigantic catalogs generated from satellite based observations.

One of the best sources of professional astronomical catalogs is the Astronomical Data Center at Goddard. http://adc.gsfc.nasa.gov/

I'd particularly recommend the catalog "Stars within 25 pc of the Sun (Wolley+ 1970)"

I hope this helps a little.
Selden


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