Dear Nora,

this issue has been fixed with ESASky 2.1 which is available online since yesterday.

Thank you for your contribution in the project.

Cheers

Dear Nora,

thank you very much to report this issue that we didn't manage to catch out in our tests. We have checked our coordinate library (where the coordinates conversion are done) and we have found that there was a bug related to a wrong usage of the Java Math.signum method. As the official Java Docs for Math.signum says, this function:

"

Returns the signum function of the argument; zero if the argument is zero, 1.0 if the argument is greater than zero, -1.0 if the argument is less than zero.

Special Cases:

• If the argument is NaN, then the result is NaN.
• If the argument is positive zero or negative zero, then the result is the same as the argument.

"

We didn't handle well the second special case, where the input number is a negative zero.

We have fixed already this bug in our library and the plan is to release it together with the new version of ESASky 2.1 in February.

Thanks again to spot this issue!

Best regards,

Fabrizio