Type II supernovae with normal spectra dominated by broad hydrogen lines that remain for the life of the decline are classified on the basis of their light curves.
32.
The two values are in fact the same distance apart from the hydrogen line the first ( 49.75kHz ) below and the second ( 49.85kHz ) above.
33.
The hydrogen line, 21 centimeter line or HI line refers to the electromagnetic radiation spectral line that is created by a change in the energy state of neutral hydrogen atoms.
34.
The same effect has been observed for other spectral lines such as the Ly-? hydrogen line and the C III ] ( ? 1909 ) line of twice ionised carbon.
35.
In addition, a small pin came loose in one engine and damaged liquid hydrogen lines in an engine nozzle, resulting in the shuttle going into a slightly lower than expected orbit.
36.
Early in Discovery's ascent, a rocket engine pressure sensor was rendered inactive by a small piece of test equipment that had been inadvertently left inside a narrow hydrogen line during ground operations.
37.
In 1972, Stirling Colgate, a professor at " Science " proposing salvaging MAR . He felt that after minor re-tuning it would make an excellent radio astronomy instrument for observing the hydrogen line.
38.
Forbidden lines of nitrogen ( [ N II ] at 654.8 and 658.4 21-cm hydrogen line is particularly important for radio astronomy as it allows very cold neutral hydrogen gas to be seen.
39.
However it is still in a core hydrogen burning phase and hydrogen lines are also visible in the spectrum, in contrast to WN stars without hydrogen which are older, less massive, and less luminous.
40.
At a cosmological redshift of z \ sim 6, Wouthuysen Field coupling is expected to raise the spin temperature of neutral hydrogen above that of the CMB, and produce emission in the hydrogen line.
