M35 is by far the most frequently observed cluster in Gemini. It is very nice with its prominent chains of stars, but with a telescope where the lowest magnification is 50 - 60x it is a bit too large to really stand out from the background milky way.
The background cluster, NGC2158, is a better object in big telescopes. Even with an 8-inch a few stars can be glimpsed in it, and with a 12-inch partial resolution is possible.
There are other fine open clusters in Gemini. A couple of degrees north of Epsilon lies NGC2266. Some magnification is recommended for this cluster, since an 8.5 magnitude star involved in the cluster tends to overpower the fainter ones at low power. 2266 can be observed in small telescopes, but an aperture of 8 inches or more is recommended for a really good view.
An even better cluster, even for very small telescopes is NGC2420. It is fairly large, but stands well out even at magnitudes in the 50 - 100x range. It is #1 in Herschel's sixth catalogue of compressed clusters.
Inge S
The background cluster, NGC2158, is a better object in big telescopes. Even with an 8-inch a few stars can be glimpsed in it, and with a 12-inch partial resolution is possible.
There are other fine open clusters in Gemini. A couple of degrees north of Epsilon lies NGC2266. Some magnification is recommended for this cluster, since an 8.5 magnitude star involved in the cluster tends to overpower the fainter ones at low power. 2266 can be observed in small telescopes, but an aperture of 8 inches or more is recommended for a really good view.
An even better cluster, even for very small telescopes is NGC2420. It is fairly large, but stands well out even at magnitudes in the 50 - 100x range. It is #1 in Herschel's sixth catalogue of compressed clusters.
Inge S
