Observer's guide
About NGC 2099
NGC 2099 (M37) is catalogued as an open cluster in Auriga. Its J2000 position is RA 05:52:18.35, Dec +32:33:10.8, corresponding to 88.0742 degrees RA and 32.545 degrees Dec. The local catalogue places it about 4,400 light-years away. Its referenced angular extent is approximately 19.3 by 19.3 arcminutes.
Observing tips
StarWatchr rates this as an easy target at magnitude 6.2. It is associated with winter observing, with midnight placement typically strongest around December. From 52 degrees north its theoretical meridian altitude is about 70.5 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 OpC. A published radial velocity value is 7.7 km/s. The SIMBAD record currently connects it to 442 bibliographic references.
At roughly 19.3 arcminutes across, it benefits from a narrower field and adequate image scale. Use the listed 19.3 by 19.3 arcminute extent to check framing, and treat catalogue magnitude as integrated brightness rather than a direct measure of visual contrast.