High resolution: https://www.flickr.com/photos/astrocamera/36298670826/in/dateposted/
The Molecular Cloud Corona Australis is an extensive object across 4.5 degrees in the sky [1]. This measurement is equivalent to about nine full moons sequentially placed in the sky. Although extensive is an extremely tenuous object. This image show just one of the ends of the molecular cloud. An area of approximately 1 degree and 13 minutes.
At a distance of about 130 pc, the Corona Australis molecular cloud complex is one of the nearest regions with ongoing and/or recent star formation. It is a region with highly variable extinction of up to AV~45 mag, containing, at its core, the Coronet protostar cluster. There are now 55 known optically detected members, starting at late B spectral types. At the opposite end of the mass spectrum, there are two confirmed brown dwarf members and seven more candidate brown dwarfs.
The two bluish clouds are called reflection nebulae. They are clouds of dust and gas that reflect the light emitted by the hot stars. The brightest nebula, located just below, is cataloged as NGC 6726 and NGC 6727. The two stars immersed in the nebula are visual binary stars where the one on the right is a variable star of short period. Just below NGC 6727, there is a fan-shaped object. This object is cataloged as NGC 6729. In this location is the cluster of Coronet protostars. Protoestrelas are objects with intense gravitational contraction that possibly will become stars. The star at the fan's edge is cataloged as R Corona Australis (R CrA). It is an extremely young variable star that still presents dust disk resulting from its formation process. The magnitude of R CrA ranges approximately between 10 and 14. The other reflection nebula is cataloged as IC 4812. In this nebula are the double stars BrsO 14 [3].
The stellar cluster seen in the upper left corner, which from the perspective looks close, is very far from the nebula at about 30,000 light-years [4]. It is the globular cluster NGC 6723 with visual magnitude 6.8. In the image we can see blue stars in the cluster. These blue stars are known as Blue Stragglers.
Source:
[1] - http://oldweb.aao.gov.au/images/captions/uks037.html
[2] - https://arxiv.org/abs/0808.3374
[3] - http://oldweb.aao.gov.au/images/captions/aat073.html
[4] - http://oldweb.aao.gov.au/images/captions/uks037a.html
I registered this image at May, 27th 2017 in rural zone of Itajá - Goiás - Brazil. Bortle scale: 2
Technical data:
ISO 800, 3h35m of exposition (43 subs), darks (200), flats (~41) e bias (200).
Equipment:
- Equatorial Mount Orion Atlas EQ-G
- GSO Ritchey-Chretien Telescope 8" F8
- Canon DSLR 500D modded with Astrodon filter
- Focal reducer Astro-Physics 67 CCDT
- Guided with ASI120MM ZWO using OAG
Software
- Capture: BackyardEOS
- Processing: PixInsight 1.8 and Adobe Photoshop CS5
- Guiding: PHD2