NavList:

Frank,

You asked:

What sort of positional information could I send that would be useful to my rescuers?

If you provided the observation time and altitude of 2 stars then they could fix your position. This double altitude sight is effectively what Doug Faunt suggested.

Alternatively the altitude and time of the parent star's meridian transit, if that is observable from your location, could be reported.

All this assumes that you or your rescuer's are able to correctly account for all the relativistic effects your clock was subject to during the voyage.

You are fortunate to be in a region where stars are visible at least some of the time. If you had crashed on the day side of a planet in a circular orbit with a tidally locked rotation period then things would have been much worse - no stars and a stationary Sun!

Robin Stuart