September 2018

As the longer, darker Autumn nights arrived, deep sky section activity began to increase as expected.

Five section members sent in their observations;  nineteen digital images and two sketches in total.

Michael Kinns produced the two sketches:   globular cluster M15 in the constellation of Pegasus and open cluster NGC 663 in Cassiopeia, using a 200mm Orion Optics f6 Newtonian reflector at 100 x magnification.

M15
NGC 663

Michael noted that NGC 663 is a rich cluster with a large number of stars between magnitude 8.8 (the two bright stars at the centre) and 11.5, with a background glow of unresolved magnitude 12 stars.

 

Mark Beveridge sent in eleven images four of which are planetary nebulae.  NGC 6781 and NGC 6804 are both in the constellation of Aquila:

NGC 6871
NGC 6804

Next, NGC 6894 is in Cygnus, and NGC 6818, the Little Gem nebula, lies in Sagittarius:

NGC 6894
NGC 6818

Mark also imaged M17, the Swan emission nebula (also known as the Omega nebula) in Sagittarius:

M17

Mark’s remaining six images are all of galaxies, three in the constellation of Pisces:  M74, NGC 488 and the NGC 507 group of galaxies:

M74
NGC 488
NGC 507 galaxy group

NGC 507 is to the right of and slightly below centre in this image.

The remaining three galaxy images are NGC 6946, in Cepheus, NGC 7015 in Equuleus and interacting galaxy pair NGC 672 and IC 1727 in Triangulum:

NGC 6946

NGC 6946 is called the Fireworks galaxy because it has had an uncommonly high number of supernovae over the last century – ten times the average number for our own milky way.

NGC 7015
NGC 672 (R) and IC1727 (L)

Mark used a Celestron Edge 200mm F10.4 SCT and an SXR-H814 mono camera plus red, green and blue filters.

 

David Davies imaged globular cluster M56 in the constellation of Lyra with an 8″ Richey Chretien f8.2 telescope, QSI 583 mono camera and red, green and blue filters:

M56

This globular orbits the centre of the milky way at a distance of about 30,000 light years, and does it in a retrograde direction, suggesting it was captured during the merger of a smaller galaxy with our own.

 

Paul Brierley sent in an image of the Wizard emission nebula NGC 7380, in the constellation of Cepheus.  Paul used an Altair Wave 115mm APO refractor and Atik 428EX colour camera:

NGC 7380

NGC 7380 is technically the open cluster within the nebulosity known as Sh2-142.  It is about 7000 light years from the Earth, and 100 light years across.  The stars in the cluster are about 5 million years old, quite young in astronomical terms.

 

Steve Norrie used a Celestron C 9.25 SCT and Starlight Xpress Trius 694 mono camera plus mainly narrow band filters filters to capture five deep sky images, switching to an ES 127 APO refractor for the sixth.

Four of Steve’s images are of emission nebulae:  NGC 7635 the Bubble nebula in the constellation of   Cassiopeia, IC 1396 the Elephant’s Trunk nebula in Cepheus, NGC 6888 the Crescent nebula in Cygnus and a wide angle shot of NGC 7635 taken with the refractor which also features open cluster M52:

NGC 7635
IC 1396
NGC 6888

NGC 6888 is also known as Caldwell 27, and Sh2-105.  It has been created by the powerful stellar wind of Wolf – Rayet star WR 136 ionising the material thrown from the star less than 500,000 years ago during its red supergiant phase.  It will end its life as a supernova, probably in just a few hundred thousand years.

NGC 7635 and M52

Steve’s final two images, in LRGB, are M27, the Dumbbell planetary nebula in Vulpecula and NGC 7023, the Iris reflection nebula in Cepheus.

M27
NGC 7023

Dave Finnigan