The Sapphire Diadem of Cassiopeia (SNR G126.2+01.6) and a new discovery

Image Title: The Sapphire Diadem of Cassiopeia (SNR G126.2+01.6) and a new discovery

Copyright: Julien De Winter, Jonathan Hill, Max Kuster, Joydeep Biswas, Jamie Moon, Nick Ambros

Date image was taken: November 26, 2025

Location: Starfront Observatory, Rockwood, TX

Data Acquisition Method: Remote Observatory (Commercial)

Description and Details: This image “The Sapphire Diadem of Cassiopeia” of SNR G126.2+01.6 represents over 1000 total hours of integration and was imaged from Starfront Observatories, Texas.

The primary subject is the SNR, which was discovered by Reich et al in 1979 with the 100m Effelsbery radio telescope.

In addition, there is at least one newly discovered object present - “Cassiopeia’s Opal” (BKDWMAH-1), a potenial new planetary nebula with strong OIII emissions and a weak Ha signal. There is also possibly a new Herbig-Haro object present, although this is subject to confirmation.

Imaging was primarily narrowband (over 1000H of OIII and Ha) with some additional LRGB data. In the end, 85% of the best data was retained, toaling 1020H of data)

Joydeep Biswas and Max Kuster began imaging in September 2025 and were then Joined by Julien De Winter who had started imaging in August 2025. Jamie Moon, Nick Ambrose and Jonathan Hill joined later, adding additional data to the project.

A multitude of equipment of varying focal lengths and sensor types was used, which created a processing challenge. Julien took the lead here, along with careful feedback from the group.

Name: Nick Ambrose

Website or Facebook Profile: https://app.astrobin.com/i/ndfht4