✨ Implement hips2fits function

src/ipyaladin/widget.py

@@ -296,6 +296,30 @@ def target(self, target: Union[str, SkyCoord]) -> None:
             }
         )
 
+    def hips2fits(self, hips: str, output_file: Optional[str] = None) -> None:
+        """Convert a HiPS image to a FITS file.
+
+        Parameters
+        ----------
+        hips: str
+            The HiPS to convert. See here for a list of available HiPS:
+            https://aladin.cds.unistra.fr/hips/list
+        output_file: str, optional
+            The name of the output FITS file. If None, the FITS file is not saved.
+
+        """
+        from astroquery.hips2fits import hips2fits
+
+        fits = hips2fits.query_with_wcs(
+            hips=hips,
+            format="fits",
+            get_query_payload=False,
+            wcs=self.wcs,
+        )
+        if output_file is not None:
+            fits.writeto(output_file)
+        return fits
+
     def add_catalog_from_URL(
         self, votable_URL: str, votable_options: Optional[dict] = None
     ) -> None: