Space, science, and the human mind. Since 1995.
Deep Field
A Space Daily column

Deep Field

Astronomy and cosmology

Deep Field covers astronomy and cosmology. Telescopes and what they find, planets near and far, and the strange physics of the deep universe, traced back to the journal papers and observatory data behind the headlines.

Science

The middle star of Cassiopeia’s W has been known since 1975 to put out X-rays no star of its type should, later measured at around 150 million degrees and roughly forty times too bright, and a satellite orbiting 570 kilometres up has now measured the iron signatures in those X-rays shifting with the orbit of an unseen companion rather than with the star itself

Three XRISM pointings spread over 169 days caught the full swing of motion in the 203-day orbit and measured the iron fluorescence line of gamma Cassiopeiae shifting by 148 kilometres per second between its two quadrature pointings. The star itself, one of the two candidate sources, moved by seven, in the opposite direction.