Observer's guide
About Whirlpool Galaxy
Whirlpool Galaxy (M51) is catalogued as a spiral galaxy in Canes Venatici. Its J2000 position is RA 13:29:52.71, Dec +47:11:42.6, corresponding to 202.4696 degrees RA and 47.1953 degrees Dec. The local catalogue places it about 37,000,000 light-years away. Its referenced angular extent is approximately 9.04 by 7.78 arcminutes.
Observing tips
This is rated as a moderate target at magnitude 8.4. It is associated with spring observing, with midnight placement typically strongest around April. From 52 degrees north its theoretical meridian altitude is about 85.2 degrees; local horizons and the live altitude chart determine the practical window.
A small telescope under reasonably dark skies is a good starting point; use the live altitude chart to choose its highest point.
What to expect
The SIMBAD classification for the matched source is Sy2. SIMBAD records the morphology as SA. A published radial velocity value is 522.5 km/s. The SIMBAD record currently connects it to 4597 bibliographic references.
At roughly 9 arcminutes across, it benefits from a narrower field and adequate image scale. Use the listed 9.04 by 7.78 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.