In base_tcs.py update find_target_simbad query

python/lsst/ts/observatory/control/base_tcs.py

@@ -1682,41 +1682,47 @@ async def find_target_simbad(
 
         customSimbad = Simbad()
 
-        customSimbad.add_votable_fields("distance_result", "fluxdata(V)")
+        customSimbad.add_votable_fields("mesdistance", "V")
         customSimbad.TIMEOUT = self.long_long_timeout
 
         radec = self.radec_from_azel(az=az, el=el)
 
-        _ra = radec.ra.to_string(u.deg, decimal=True)
-        _dec = radec.dec.to_string(u.deg, decimal=True, alwayssign=True)
-        r = Angle(radius * u.deg).to_string(u.deg, decimal=True)
-
-        criteria = (
-            f"region(circle,ICRS,{_ra} {_dec},{r}d) & "
-            f"Vmag > {mag_limit} & Vmag < {mag_limit+mag_range} & "
-            "cat = HD"
-        )
-
+        # Execute the query_region asynchrnously
         loop = asyncio.get_event_loop()
-
         try:
             result_table = await loop.run_in_executor(
-                None, customSimbad.query_criteria, criteria
+                None, customSimbad.query_region, radec, radius * u.deg
             )
         except Exception as e:
-            self.log.exception("Querying Simbad failed. {criteria=}")
-            raise RuntimeError(f"Query {criteria=} failed: {e!r}")
+            self.log.exception("Querying Simbad failed.")
+            raise RuntimeError(f"Query region for {radec} failed: {e!r}")
 
-        if result_table is None:
-            raise RuntimeError(f"No result from query: {criteria}.")
+        if result_table is None or len(result_table) == 0:
+            raise RuntimeError(f"No results found for region around {radec}.")
 
-        result_table.sort("FLUX_V")
+        # Filter by V magnitude
+        good_mag = (result_table["V"] > mag_limit) & (
+            result_table["V"] < (mag_limit + mag_range)
+        )
+        result_table = result_table[good_mag]
+
+        # Further filter for HD objects (prefix "HD")
+        hd_mask = [str(name).startswith("HD") for name in result_table["main_id"]]
+        result_table = result_table[hd_mask]
+
+        if len(result_table) == 0:
+            raise RuntimeError(
+                f"No 'HD' object in Simbad catalog with magnitude between"
+                f" {mag_limit} and {mag_limit+mag_range}."
+            )
 
-        target_main_id = str(result_table["MAIN_ID"][0])
+        # Sort by V magnitude
+        result_table.sort("V")
+        target_main_id = str(result_table["main_id"][0]).strip()
 
         radec_icrs = ICRS(
-            ra=Angle(result_table[0]["RA"], unit=u.hourangle),
-            dec=Angle(result_table[0]["DEC"], unit=u.deg),
+            ra=Angle(result_table[0]["ra"], unit=u.hourangle),
+            dec=Angle(result_table[0]["dec"], unit=u.deg),
         )
         self.object_list_add(f"{target_main_id}".rstrip(), radec_icrs)