3C461 (Cas A)

Instrument : Celestron 11 (D = 0.28 m) + LISA spectrograph (click here for technical informations) at R = 800 + Atik 314L+ CCD camera
Observatory : Castanet-Tolosan
Observer : Christian Buil
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3C461 (Cas A) is the faint remnant of supernova explosion observed by british astronomer John Flamsteed in 1680. It is the youngest know Galactic supernova remnant.
The spectrum is complex because the three-dimensional high velocities field and the knots structure with a high diversity spectral signature.

The spectrum show fast-moving knots (FKMs), up to 11000 km/s, and slow-moving knots (200 km/s max) also called "Quasi Stationary Flocculi", QSFs.

My spectra shows clearly bright [O III] FKMs, concerning also sulfur element. Nitrogen QSF are also detected (section "S2" - below). The Halpha line is nearly absent (very faint in scan "S2") :

Click here or in the image for enlarge.