The number of gaseous nebulae (planetaries and diffuse) is surprisingly low. I have a total of four in my observing records, the most impressive one by far being the Eskimo nebula, NGC2392.
The second brightest nebula in Gemini must be peanut shaped NGC2371/2372. It isn't awfully hard to detect with an 8-inch telescope, and can probably be seen with a good 4-inch (less?). It is smaller and fainter than M76, and its interesting shape is best seen with a magnification of 100x or more. I have not seen its central star, but it should be detectable with a 12-inch.
The third of my recorded Gemini nebulae was a very nice surprise in my 12.5-inch. This is the large planetary, PK205+14.1 . It took some effort to find it. I used Lambda Geminorum as a guide to the cluster NGC2395 (which I didn't find very impressive - just an enrichment in the background star field). Just a degree to the south-east a faint haze could be seen without a filter. The O-III filter worked wonders on this planetary, also called the Medusa neubla. It has a very unusual shape, more like a crescent moon, large and much brighter than I would have expected for an object listed neither in the NGC nor the IC catalogue. I think it can be seen with a smaller aperture.
The last nebula in my records is the supernova remnant, IC443, located near the difficult double, Eta Geminorum. I'm positively unable to see anything without a filter. With an O-III an elongated, extremely faint haze can be made out. I would never have detected it if I didn't know its exact position. It is definitely the most difficult nebula in my observation records.
Inge S
The second brightest nebula in Gemini must be peanut shaped NGC2371/2372. It isn't awfully hard to detect with an 8-inch telescope, and can probably be seen with a good 4-inch (less?). It is smaller and fainter than M76, and its interesting shape is best seen with a magnification of 100x or more. I have not seen its central star, but it should be detectable with a 12-inch.
The third of my recorded Gemini nebulae was a very nice surprise in my 12.5-inch. This is the large planetary, PK205+14.1 . It took some effort to find it. I used Lambda Geminorum as a guide to the cluster NGC2395 (which I didn't find very impressive - just an enrichment in the background star field). Just a degree to the south-east a faint haze could be seen without a filter. The O-III filter worked wonders on this planetary, also called the Medusa neubla. It has a very unusual shape, more like a crescent moon, large and much brighter than I would have expected for an object listed neither in the NGC nor the IC catalogue. I think it can be seen with a smaller aperture.
The last nebula in my records is the supernova remnant, IC443, located near the difficult double, Eta Geminorum. I'm positively unable to see anything without a filter. With an O-III an elongated, extremely faint haze can be made out. I would never have detected it if I didn't know its exact position. It is definitely the most difficult nebula in my observation records.
Inge S
