Observer's guide
About NGC 5904
NGC 5904 (M5) is catalogued as a globular cluster in Serpens Caput. Its J2000 position is RA 15:18:33.75, Dec +02:04:57.7, corresponding to 229.6384 degrees RA and 2.081 degrees Dec. The local catalogue places it about 24,500 light-years away. Its referenced angular extent is approximately 17.4 by 17.4 arcminutes.
Observing tips
StarWatchr rates this as a very easy target at magnitude 5.6. It is associated with summer observing, with midnight placement typically strongest around May. From 52 degrees north its theoretical meridian altitude is about 40.1 degrees; local horizons and the live altitude chart determine the practical window.
Its brightness makes it a practical binocular or small-telescope candidate when it is well above the horizon.
What to expect
The SIMBAD classification for the matched source is GlC. A published radial velocity value is 53.8 km/s. The SIMBAD record currently connects it to 2109 bibliographic references.
At roughly 17.4 arcminutes across, it benefits from a narrower field and adequate image scale. Use the listed 17.4 by 17.4 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.