7139 is a planetary nebula located in the constellation of Cepheus.
discovered by Hershel in 1787, but only in 1918 it was understood it is a
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.
Technical data 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,
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