M 46 is a rich open star cluster in Puppis constellation.
Inside the cluster it is visible a small planetary nebula, NGC 2438: but in reality this is only for a perspective effect, because M46 has a distance of 5400 light years, while NGC 2438 has a distance of 2900 light years.
On the image it is visible also another very faint planetary nebula, PK 231+4.1, with magnitude 14.4: you can see it as a little disk at about the half distance between NGC 2438 and the right side of the image.
Apo Refractor LT 130 - 910mm f/7
Mount 10Micron GM2000 HPSII
Camera Moravian G3-16200 with external filter wheel 7 positions
Filters Baader RGB 50.8 unmounted
Guiding system OAG Moravian M68 with guide camera Moravian G1-0301
Exposure details R 8x300" bin1 -20C
G 8x300" bin1 -20C
B 8x300" bin1 -20C
Total integration 2h
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5
Location Promiod (Aosta Valley, Italy), own remote observatory
Date 12 January 2018