SP-168 EXPLORING SPACE WITH A CAMERA
During two hours of extravehicular activity on Gemini Xl,
Astronauts Conrad and Gordon photographed ultraviolet stellar spectra
in six regions of the sky. The camera was attached to the spacecraft
frame; Gordon stood up in the open hatch to operate it while Conrad
remained in his seat to control attitude and time the exposures.
Of the photograph of Canopus above, astronomer KARL G.
HENIZE of Northwestern University, who is now himself an astronaut,
"The numerous short horizontal lines are zero-order images
of background stars which are elongated due to a slight yaw motion of
the spacecraft. The vertical streak directly below this bright
zero-order image of Canopus is its spectrum. The lower portion of the
spectrum shows lines due mainly to the familiar Balmer series of
hydrogen. At the upper end appear several newly observed ultraviolet
absorption lines, the strongest of which is the ionized magnesium
doublet at 2800 A. Other features are clue to silicon and to neutral
and ionized iron.
"This photo was obtained with the 73-mm focal length,
f/3.3 lens of the Maurer camera, to which a 600 line/mm diffraction
grating was attached. The exposure time was 20 seconds.
"This spectrum is the first to show absorption lines in
the 2200- to 3000-A wavelength region of a star other than the Sun."
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