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This image has been selected as APOD (Astronomy Picture Of The Day, NASA) on 09/20/2018.
This image has been displayed in the Hugo Giovannetti’s Facebook page “Space Learner” on September 23rd, 2018.
This is one of the most beautiful regions in the sky. It is also an interesting one, with different kinds of objects in it. It is due to the four very bright and blue stars, that we can see that there is dust in this region. Their light, reflected by the surrounding dust is dispersed and therefore color shifted to bluer shades. This makes this nebular complex aesthetically very attractive. But this image shows more than that.
The blue nebular complex consists of four catalogued objects: NGC 6726 (the left half of the reflection nebula on the right -Northwest-), NGC 6727 (the right half of the reflection nebula on the right), NGC 6729 (the upper portion of the nebula on the right) and IC 4812, the reflection nebula located on the left side of the picture (see annotated image below).
Additionally, being this region a starbirth site, we can see several Herbig Haro objects (up to thirteen in this image). The list would be (from left to right): HH101N, HH82, HH96, HH97 (not annotated here, because it lies just below HH96’s letters), HH101, HH731A, HH731B, HH100, HH98, HH104, HH735, HH99 and HH735A. Most of these HH objects are usually not (or just barely) seen in LRGB images. This image was taken also in LRGB, as well as with 8 hours with Halpha filter, in order to show them better.
Additionally, the cherry on top of the cake, the image also shows a distant (and beautiful) face-on galaxy, 2MASX J19002351-3712243. This 15.1 magnitude galaxy lies 355 Million light years away and it is far enough to show a (low, but measurable) redshift of 0.02565. It is located on the far left of the image center.
Name(s): NGC 6726, NGC 6727 and more…
Type: Reflection Nebula and HH objects
RA: 19h 01m 41s
Dec: -36º 51’ 56”
Constellation: Corona Australis
Size (arcmin): 20×10
Distance: 450 ly
Date: 2018-06-23 thru 2018-07-15
Location: iTelescope.net, SSO near Coonabarabran, NSW Australia
Size (arcmin): 35×27
Telescope: Planewave CDK 20” f/6.8
Camera: SBIG STX16803 (4096x4096pix)
Guiding: Astrodon MonsterMOAG off-axis guider
Total exposure: 18.5 hours (Ha: 8h; L: 3h45m; RGB: 6h45m)
Processing: CCDStack, Photoshop CC 2018