Popular Astronomy

August 2015

A busier month for Deep Sky section, with more hours of astronomical darkness prompting five section members to send in their observations.

Dale Holt made five drawings. Below left is NGC6327 (slightly left and below centre) plus NGC6329 upper right) and a third faint galaxy (far left).  NGC6327 is magnitude 15 and is in the constellation of Hercules. On the right, below, is PGC599984, a galaxy close to glogular cluster M92, also in Hercules.                 



                                                                                                                                                                                                  Dale's next sketches were of NGC7006, a globular cluster in Delphinus, (below left).  Also known as Caldwell 42, this globular is about 135,000 light years from the Earth. In this sketch there are a number of faint galaxies too.

Below right is a sketch of NGC7033 and NGC7034, a pair of elliptical galaxies in the constellation of Pegasus.


Dale's fifth sketch, right, is NGC7036, also in the constellation of Pegasus. This is an open cluster of stars, about 3,300 light years from the Earth. Again, a number of much more distant background galaxies appear in this sketch.

Dale used his 505mm f 3.5 Newtonian telescope with a cooled Watec120N video camera, drawing the live images as they appeared on the monitor screen.



Ian Papworth sent in a selection of images of M27, the "dumbbell" planetary nebula in the constellation of Vulpecula.  The first two, below left and right, are a monochrome image plus its negative version, highlighting the faint outer structure.                                                                                                     



The next images, show M27 imaged through a selection of filters:  left Hydrogen alpha, right OIII, bottom left H alpha combined with OIII, and bottom right RGB.




  Ian also imaged M15, a globular cluster in the constellation of Pegasus (below left), and M76 the "little dumbbell" planetary nebula in Perseus.  M15 is about 33,600 light years from the Earth, and is one of the most ancient globulars at 12 billion years old.  It is one of the most densly packed globular clusters, having experienced what is called "core collapse" such that half of its total mass is in a region of about one light year across at the centre, possibly surrounding a black hole. 



Ian used a Celestron 6SE f6.3 Schmidt Cassegrain telescope with a ZWO ASI 120MM camera plus filter wheel.

 Mike Wood sent in four drawings to the section this month, all of deep sky objects in the constellation of Aquila.  The first two are NGC6755, an open cluster (below left) and NGC6778, a planetary nebula. Mike used a Celestron 9.25 SCT;  the magnification employed is shown on each sketch.



The next two drawings are both of planetary nebulae, NGC6871 (below left) and NGC6804.


Toby Papworth observed and sketched M27, the "dumbbell"   planetary nebula, shown on the right.  Toby uses a 3" Celestron Newtonian telescope.

This was the first planetary nebula that Charles Messier discovered, in 1764.  With a visual magnitude of 7.3 and an angular size of 8 x 5 minutes of arc it is easily found in binoculars and small telescopes, and is a perenial favourite of amateur astronomers.  An OIII filter is helpful for visual observers.  



Graham Taylor sent in three images, the two below taken via the Bradford remote telescope.  Below left is NGC4565, an edge - on spiral galaxy in the constellation of Coma Berenices.  At the top left of this image is another galaxy, NGC4562.  Below right is NGC185 also known as Caldwell 18,, a dwarf spheroidal galaxy in the constellation of Cassiopeia.  This galaxy has an active nucleus and is the only known Seyfert galaxy in our local group.


Graham's final image was taken via a different remote telescope at the MicroObservatory Arizona, which goes by the name of "Donald";  one of several 6" reflecting telescopes at this site.  This of course is M81, also known as Bode's galaxy, in the constellation of Ursa Major.  This galaxy too has an active nucleus, and is the largest of a group of galaxies about 12 million light years from the Earth.


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