Instrument

Takahashi FSQ-106ED @ f/5.0 (530 mm F.L.) Captured at 2.1 arcsec/pixel.  Shown at 3.88 and 9.32 arcsec/pixel.

Mount

Losmandy G11 with Gemini L4 v1.0

Camera

SBIG STF-8300M Self Guiding Package w/ mono ST-i, using an AstroDon 5nm Ha and Baader RGB filters.

Acquisition Data

8/6/2015 to 9/17/2015 Chino Valley, AZ... with CCD Commander & CCDSoft.

Exposure

RGB ratios are 1.00, 1.21 & 1.41

Software & Processing Notes

• CCDSoft, CCDStack, PixInsight and Photoshop CS6.

• A standard image-train calibration was used for star color, as determined by eXcalibrator v4.30, and then adjusted for altitude extinction. My best guess for the nebula color in the mouse-over view.

• CCDStack to calibrate, register, normalize, data reject and mean combine the RGB sub exposures and creating the RGB image.

• PixInsight processing includes gradient repair, non-linear stretching with HistogramTransformation and HDRMultiscaleTransform.

• PhotoShop for creating the Ha:RGB image and adding the 30% RGB.

• Noiseware 5, a PhotoShop plug-in.

• Click here for the color-mapped NarrowBand images
  Click here for the Ha image.

Comment

North is to the top.

Sharpless 115 stands just north and west of Deneb, the alpha star of the constellation Cygnus, the Swan. Noted in the 1959 catalog by astronomer Stewart Sharpless (as Sh2-115) the emission nebula lies along the edge of one of the outer Milky Way's giant molecular clouds, about 7,500 light-years away. Hot stars in star cluster Berkeley 90 power the nebular glow. The cluster stars are likely only 100 million years old or so and are still embedded in Sharpless 115.
Source: NASA APOD

The small bight object, near the top, is Abell 71. The nebula is also cataloged as PK 085+04.1, PN G084.9+04.4 and Sh 2-116. Initially cataloged as a planetary nebula, the object is now recognized as an HII region.