Bibcode
                                    
                            Simpson, Jordan; Jones, David; Wesson, Roger; García-Rojas, Jorge
    Referencia bibliográfica
                                    Research Notes of the American Astronomical Society
Fecha de publicación:
    
                        1
            
                        2022
            
  Número de citas
                                    7
                            Número de citas referidas
                                    6
                            Descripción
                                    A30 belongs to a class of planetary nebulae identified as "born-again", containing dense, hydrogen-poor ejecta with extreme abundance discrepancy factors (ADFs), likely associated with a central binary system. We present intermediate-dispersion spectroscopy of one such feature-the J4 equatorial knot. We confirm the apparent physical and chemical segregation of the polar and equatorial knots observed in previous studies, and place an upper limit on the ADF for O2+ of 35, significantly lower than that of the polar knots. These findings further reinforce the theory that the equatorial and polar knots originate from different events.