August EAA Targets

 Summary  Easy: M27 and M57; Intermediate: NGC7000 and IC5070; Difficult: IC1396a/LBN 452 and IC59 & IC63; Deep Southern: M16 and M17

 

Easy: M27 (Dumbbell Nebula) (20h 01m  / +22d 47') and M57 (Ring Nebula) (18h 55m  / +33d 03')  - Note: approximate JNOW co-ordinates.



M27 (Dumbbell Nebula)

The Dumbbell Nebula is a planetary nebula about 1,200 light years distant in Vulpecula. Its brightness and relatively large apparent size (for a planetary nebula) make it a favourite EAA  target. Deeper views show faint outer lobes of the nebula, while the central region contains many bright knots; the nebula is also very prominent in H-alpha. Here are a couple of views (unfortunately only in monochrome). First is a 3 minute monochrome capture with my C8 @ f/3.7, and an ASI290MM mini at 300 gain:

 


M27( Dumbbell Nebula, ASI290MM mini/C8); 18 x 10s


The second is a wide-field single 45sec H-alpha capture with a ST80 @ f/4.0, and LodestarX2 mono:

  


M27 (Dumbbell Nebula, H-alpha, Lodestar X2M / ST80); 1 x 45s


M57 (Ring Nebula)
At the small end of the apparent size scale is this bright and most famous of all planetary  nebulae, 2000 light years away in Lyra. The Ring Nebula has a white dwarf at its centre, that is the source for the material ejected into the nebula. The 16th magnitude central star as well as another star, are visible in this unfiltered and cropped quick 30 second mono view using the C8 set-up described above. Bonus points for capturing a satellite trail, as I did, or the challenging, but tiny, 16th magnitude galaxy IC1296, visible as a smudge 4' away at the 2 o'clock position towards the upper right:

 


M57(Ring Nebula, ASI290MM mini/C8); 6 x 5s





Intermediate: NGC7000 (North America Nebula) (21h 00m  / +44d 37') and IC5070 (Pelican Nebula) (20h 52m  / +44d 29')

 

NGC7000 (North America Nebula) and IC5070 (Pelican Nebula)

At the other extreme of the apparent size scale is this huge emission nebula complex in Cygnus, about 2600 light years away. The combined nebulae covers several degrees and is a challenge to capture in its entirety without a large sensor camera or short focal length scope. The North America Nebula and nearby associated Pelican Nebula (IC5070) are both H-II ionized gas regions that show up well in H-alpha views. I have tried EAA captures without a filter and been disappointed, but others may have more success. Here are a couple of older captures taken in H-alpha with a low resolution LodestarX2 mono and H-alpha filter. The first is a very wide-field view through a 135mm f/2.8 Chinon telephoto lens that captures both the North America and Pelican:

 


NGC7000, IC5070 (North America & Pelican Nebula, H-alpha, LodestarX2M/ Chinon ); 6 x 45s 





The second view is just The Cygnus Wall region of the North America Nebula (narrower, southern part of the nebula) in H-alpha with the ST80 @ f/4.0, LX2M camera and 7nm H-alpha filter:

 


NGC7000 (The Cygnus Wall region, H-alpha, LodestarX2M/ ST80); 16 x 45s





Difficult: IC1396a/ LBN452 (Elephant Trunk Nebula) (21h 37m / +57d 30') and IC59 & IC63 (The Ghost of Cassiopeia) (00h 59m / +61d 16' & 01h 01m / +61d 02')

 


IC1396a (Elephant Trunk Nebula)

The Elephant Trunk Nebula is a dark globule, a dark and dense gas cloud that is a region of star formation, about 45 arcmins in size and 2400 light years distant. It is part of the much larger (3 degrees in size) emission nebula IC1396 in Cepheus. Most of the gas in  IC1396 is ionized by a hot O type star, except for dark globules like the Elephant Trunk Nebula. The Elephant Trunk Nebula can be captured without a H-alpha filter using a mono camera  even with light pollution. However,  I have found it much more noticeable when using a H-alpha filter. It may be a challenge to see using a colour camera without a narrowband filter.

 

Here is a H-alpha view of the Elephant Trunk (silhouetted against part of the large  IC1396 emission nebula), using the ST80/LX2M set-up reduced to f/3.1:

 

 

 

IC1396a (Elephant Trunk Nebula, H-alpha, LodestarX2M/ ST80); 12 x 45s






IC1396a (Elephant Trunk Nebula, H-alpha, ASI290MM mini/ AT130EDT); 10 x 30s

Here is a deeper (and more recent) cropped H-alpha  capture of the Elephant Trunk, taken with an AT130EDT  and ultrafast afocal set-up (8mm CCTV and 25mm Plossl), yielding f/2.1. The 5 minute image was taken with an ASI290MM mini at 300 gain:



 











IC59 & IC63 (The Ghost of Cassiopeia)
Located in Cassiopeia, at a distance of about 600 light years, IC59 is mostly a reflection nebula with little H-alpha emission, so it appears much fainter in H-alpha than the neighbouring, but more prominent IC63, which is both a reflection and emission nebula. The intense radiation from nearby Gamma Cass on IC63, results in H-alpha emission from IC63, also known as the Ghost of Cassiopeia. In colour images IC59 appears bluer than IC63 as a result of its stronger reflection component. It's interesting that as IC63 is closer to Gamma Cass. , ionization of the clouds from Gamma Cass. and the resulting H-alpha emission is stronger in IC63 than IC59.


Gamma Cass is just outside the FOV at the lower right in this 3 minute H-alpha capture using an AT130EDT in a f/1.6 ultrafast afocal set-up (8mm CCTV and 40mm Plossl) with an ASI290MM mini at 300 gain:




IC59, IC63 (Ghost of Cassiopeia, H-alpha, ASI290MM mini/ AT130EDT); 12 x 15s




Deep Southern: M16 (Eagle Nebula) (18h 20m  / -13d 48') and M17 (Omega Nebula) (18h 22m  / -16d 10')


M16 (Eagle Nebula)
Although this bright summer emission nebula located in Serpens, and its nearby neighbour, M17, may not technically qualify as "deep" southern targets, they are at least south of the celestial equator and well placed for both northern and southern observers this month. M16 is about 6500 light years distant and includes NGC6611, a young star cluster, within its limits and the celebrated star forming region, known as the "Pillars of Creation", towards the southern end of the nebula. One challenge with this target is to see how far out you can trace wisps of nebulosity in  the wings of the Eagle. The wide field 7 minute exposure  below was taken with an AT72EDII reduced to f/4.4, ASI290MM mini mono at 300 gain 300 using an ancient Lumicon Deep Sky Filter:



M16 (Eagle Nebula, Deep Sky Filter, ASI290MM mini/AT72EDII); 48 x 10s

The dark, but cool, dust and gas clouds which compose the Pillars, collapse under gravity and give birth to new stars. The "Pillars of Creation" shows a little more prominently in this 12 minute H-alpha capture taken using a 7nm H-alpha  with an AT130EDT reduced to f/5.5 and ASI290MM mini at 300 gain:


M16 (Eagle Nebula, H-alpha, ASI290MM mini/AT130EDT); 24 x 30s


M17 (Omega Nebula)
Located about 5,500 light years away in Sagittarius, the Omega (or Swan) Nebula,  like the Eagle Nebula, is a very bright HII nebula, featuring very active star forming regions, and a young open cluster (NGC6618) embedded in the nebulosity.  

The HII emission nebulosity in the Omega Nebula is very bright, more so than similar regions in the Eagle Nebula. The nebulosity appears very prominent in this old 3+minute H-alpha capture taken using a 7nm H-alpha filter, with a venerable ST80 achromat reduced to f/4.0, and ASI290MM mini at 300 gain: 


M17 (Omega Nebula, H-alpha, ASI290MM mini/ST80); 13 x 15s










Have fun with these targets, everyone!

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