Astr 327 Homework #3
Items:
- Homework assignment (in postscript)
- Homework assignment (in LaTeX)
- Flynn and Freeman dataset
In this dataset, the coordinate of galactic latitude and longitude are
given by _Glon and _Glat, the apparent mag of the star is Vmag and the
absolute magnitude is Mv. From these data you should be able to construct
the stars' z-coordinate. Then RV is the stars' observed line of sight
radial velocity; you'll need to convert it to the stars' z velocity.
The other columns (RA and Dec) are superfluous...
- Peterson etal dataset:
- radial velocity
In this dataset, the important data is distance from center of cluster
("Dist" in arcmin) and position angle ("PA" in degrees). These two values
will give you the (x,y) of the star w.r.t. the cluster center. RV is then
the observed line of sight radial velocity of the star. You'll need
to calculate, and subtract out, the mean line of sight radial velocity of the
cluster.
- proper motion
In this dataset the x,y position of the star w.r.t. the cluster is given directly
(note that this is a different set of stars from the previous dataset!).
then the proper motion of each star is given in mu_x and mu_y, in units of
milliarcseconds per year. Make sure to solve for and subtract out any mean
proper motion of the star cluster. Realize that if you have an observed proper
motion (which is an angular velocity), if you know the distance you can solve
for the true velocity, or vice versa.
- Fortran code snippet to convert r,v to cartesian