Observer's guide
About Bubble Nebula
Bubble Nebula (C11) is catalogued as an emission nebula in Cassiopeia. Its J2000 position is RA 23:20:46, Dec +61:12:24, corresponding to 350.2012 degrees RA and 61.2017 degrees Dec. The local catalogue places it about 7,100 light-years away. Its referenced angular extent is approximately 41.67 by 41.67 arcminutes.
Observing tips
This is rated as a moderate target at magnitude 10. It is associated with summer observing, with midnight placement typically strongest around September. From 52 degrees north its theoretical meridian altitude is about 80.8 degrees; local horizons and the live altitude chart determine the practical window.
Because it is faint, use a larger aperture where possible, avoid bright Moon conditions, and use averted vision.
What to expect
The SIMBAD classification for the matched source is HII. The SIMBAD record currently connects it to 179 bibliographic references.
Its roughly 41.7 arcminute span suits a medium field of view. Use the listed 41.67 by 41.67 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.