In the thread referred to, a number of us identified problems with some planetarium programs.
For accurate ephemerides, you need to use one of the following sources :
NASA Horizons Web Interface
http://ssd.jpl.nasa.gov/horizons.cgi#top
the Ephemeris Service of the Minor Planet Center - at
http://www.minorplanetcenter.net/iau/MPEph/MPEph.html
(Specify the object as:
2012 DA14 and enter your specific location.)
ChrisM has also identified Heavens Above. I tried this interface quickly. It seems to generate a circular chart depicting the sky displaying ALT AZ over time. Accordingly, it cannot display stars because they move over time. The other two interfaces allow you to choose your own time interval, Heavens Above doesn't give you a choice, it is a default 1 hr intervals. I've used 15min intervals for the latter part. This still leaves 7 degrees between plot points.
Because the object is so close to Earth even a short distance will be noticable eg -
North to South Canberra......2 minutes of arc difference
Brisbane to Sydney..............1 degree difference
If looking with an eyepiece giving a half degree field, it isn't going to matter if you have coords for your town or city and are a few minutes out.
On the other hand, look with a chart generated for the wrong city and it will be a couple of eyepiece fields away. Time is also important. By the time it brightens to easy visibility in a small telescope, it will have an apparent motion of 0.5 deg/min so make sure you have a reasonably accurate time source (A GPS displays time accurate to within a few seconds - this should be good enough) and go to a location in the sky ahead of time and wait for it.
Joe Cali
