astropy/astropy — pull request #1496 by astrofrog (2013-12-01 11:45:38+00:00)
Title: E-term calculation uses equinox but should use observation date

Currently, the calculation of e-terms uses the equinox:

```
eterms_a = fk4_e_terms(fk4c.equinox)
```

but this should be the observing epoch/date. We need to also make the accuracy tests more accurate to ensure that we catch this.