Instrument

Takahashi FSQ-106ED @ f/5.0 (530 mm F.L.) Captured at 2.1 arcsec/pixel.  Shown at 4.2 and 2.76  arcsec/pixel.

Mount

Paramount MyT

Camera

SBIG STF-8300M Self Guiding Package w/ mono ST-i, using AstroDon E-Series RGB, 5nm Ha and 3nm OIII filters.

Acquisition Data

2/3/2016 to 4/5/2016  Chino Valley, AZ with CCD Commander & CCDSoft. 

Exposure

 eXcalibrator RGB ratios are 1.00, 0.88, 0.85

Software

• CCDSoft, PixInsight & Photoshop CS6.

• eXcalibrator v4.36 for (g:r) color balancing, using 278 stars from the SDSS-DR9 database.

• PixInsight processing includes calibration, registering, stacking, RGB creation, gradient removal and non-linear stretching with HistogramTransformation.

• PhotoShop for adding the Ha and OIII to the RGB image and the final touch up.

• Noiseware 5, a PhotoShop plug-in.

Comment

North is to the top.

Sh2-290 (Abell 31) is a very old planetary nebula in the constellation Cancer, at a distance of about 2000 light years. As planetary nebulae expand, they gradually disperse into space. This, combined with the nebula's advanced age, probably accounts for the low surface brightness. Sh2-290 is moving through space at a high speed, creating a sharp bow shock on the southern side. The northern side is rather diffuse as the nebula disperses downwind.