Planetary Nebula Messier 27

The Dumbbell (or Apple Core) Nebula

 

Planetary nebula Messier 27 - a shell of fluorescing ionised hydrogen (red) and ionised oxygen ( green/blue) surrounds the remnants of a once active star - probably not unlike our own Sun. The white dwarf remnant star can be seen at the centre of the nebula.

 

The hard UV light from the white dwarf makes the surrounding ionised gases fluoresce in characteristic colours. The clouds of gas were probably shrugged off the star in the final phases of its life.

 

Deeper images show further shells of gas which are just hinted at here.

 

Size is 8.0 x 5.6 arcminutes

 

This is a combination of 2 sessions; one from 2020 with a modified Canon 80d and one from 2021 with a ZWO ASI2600 MC pro CMOS cooled camera. Both sessions were under full Moon.

 

Interestingly, both cameras have the same pixel size at 3.76 um and both have APS-C size chips.

 

Canon 80D: 13 x 5 minute subs at ISO 400

ASI2600MC 20 x 3 minute subs at gain 100, offset 50 at 0c.

Equinox ED 900mm f/7.5 scope x0.85 focal reducer.

IDAS P3 LPS 2"filter in focal reducer.

ZWO ASI2600MC Pro; Gain:100, Offset:50 @0c (2021).

SkyWatcher EQ6 pro mount with Rowan belt drives.

Guided by PHD2 via PrimaLuce 240mm f/4 guidescope.

 

50 flats (EL panel at 1/4 second)

50 darks at 0c

50 bias at 0c and 1/16000s

 

Polar Alignment:

QHY Polemaster alignment -

Error measured by PHD2= 1.8 arc minute.

RA drift + 2.07 arcsec/min

Dec drift +0.47 arcsec/min

 

Guiding:

PHD2 guiding with ZWO ASI290mm/PrimaLuce Lab 240/60mm guide scope.

RA RMS error 0.76 arcsec.

Dec RMS error 0.83 arcsec.

 

Astrometry:

Resolution ............... 0.986 arcsec/px

Focal distance ........... 786.27 mm

Pixel size ............... 3.76 um

Field of view ............ 36' 15.0" x 28' 53.1"

Image center ............. RA: 19 59 35.670 Dec: +22 43 59.87

Done