NGC 7139 is a planetary nebula located in the constellation of Cepheus.
It was discovered by Hershel in 1787, but only in 1918 it was understood it is a planetary nebula.
Its diameter is 77” and its visual magnitude 13, while the central star has magnitude 18.72.
This nebula has a good emission in both Ha and OIII wavelenght and its structure is somewhat reminiscent of the more famous nebula M27: indeed it is characterized by the presence of two bright condensations while, on the perpendicular axis, two faint lobes are visible.
Optic GSO RC12 Truss - Aperture 304mm, focal lenght 2432mm, f/8
Mount 10Micron GM2000 HPSII
Camera Moravian G3-16200 with external filter wheel 7 positions
Filters Astrodon 50mm narrowband filters Ha 5nm and OIII 5nm
Guiding system OAG Moravian M68 with guide camera Moravian G1-0301
Exposure details Ha 67x300" bin2 -10C
OIII 67x300" bin2 -10C
Total integration 11,2h
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5
SQM-L 20.0 (images taken with the presence of Moon)
Location Promiod (Aosta Valley, Italy), own remote observatory
Date 31 July / 6-7 August 2020