What highly ionised elements are found in the spectrum of WR 102c?
WR 102c WR 102c is a Wolf–Rayet star located in the constellation Sagittarius towards the galactic centre. It is only a few parsecs from the Quintuplet Cluster, within the Sickle Nebula.
SN 2005gj SN 2005gj was a supernova located approximately 864 million light years (265 million parsecs) away from Earth. It was discovered on September 29, 2005, by the Sloan Digital Sky Survey and the Nearby Supernova Factory. 2005gj was noted because it had qualities of both type Ia and type IIn supernovae, and because hydrogen emission lines were found in its spectrum (see hydrogen spectral series). These hydrogen lines, which were found on the spectrum at redshift z=0.0613, are thought to be indicative of interactions with a circumstellar medium (CSM; a donut-shaped, nebula-like ring of matter around a star) by the supernova's ejected matter or white dwarf progenitor. Such emission lines are extremely rare in Type Ia supernovae – only one other Type Ia, SN 2002ic, has been observed to exhibit the same properties. However, 2005jg's CSM interaction was much stronger and more clearly observed than 2002ic's. The mass-loss history 2005gj's hydrogen lines suggest has been cited as evidence that Luminous Blue Variable (LBV) hypergiants can be progenitors of thermonuclear supernovae.