Our publication today is a trial on an object of very low surfacic magnitude (-16) but we wanted to try to image even thoug

h all the photos on the net are taken with instruments large and/or very open. The OIII brutes show a barely discernible signal and it was impossible to discern anything about the Ha... A stacking on 10 poses showed us that a signal was nevertheless visible, we tried to image the beautiful. So here's the result with a 315mm of Fd 8, it's below what we hoped but much better than we could have feared.

Abell 7 or PK215-30.1

The very discrete and ancient planetary nebula Abell 7 is about 1,800 light-years away, just south of Orion, in the constellation Lepus. Surrounded by stars from the Milky Way and angularly close to distant background galaxies, its spherical shape of some 8 light-years in diameter is sketched in this telescope image. Internal details are revealed through the use of filters. Hydrogen and nitrogen emissions appear in shades of red while oxygen emissions are blue-green. These nuances are absolutely imperceptible to human vision. The planetary nebula phase represents a very brief episode of the end-of-life of the stars that our own Sun will experience in 5 billion years, when it expels its outer layers. Abell 7 has an estimated age of 20,000 years, with its central star WD 0500-156 which is probably a double system with a dwarf companion located at 0.91 sec, which became a pale white dwarf after 10 billion years of intense radiation.
Pictured is the galaxy at the right is PGC 1611.