seemed like an eternity--five and a half gravities of acceleration
held the men in their chairs almost as well as the straps of the
antiacceleration units that bound them. When a man weighs better than
half a ton, he doesn't feel like moving much.

Fuller whispered to Morey out of the corner of his sagging mouth. "What
on Earth--I mean, what in Space is that thing? We're within only a few
hundred miles, you said, so it must be pretty small. How could it pull
us around like this?"

"It's a dead white dwarf--a 'black dwarf', you might say," Morey
replied. "As the density of such matter increases, the volume of the
star depends less and less on its temperature. In a dwarf with the mass
of the sun, the temperature effect is negligible; it's the action of the
forces within the electron-nucleon gas which makes up the star that
reigns supreme.

"It's been shown that if a white dwarf--or a black one--is increased in
mass, it begins to decrease sharply in volume after a certain point is
reached. In fact, no _cold_ star can exist with a volume greater than
about one and a half times the mass of the sun--as the mass increases
and the pressure goes up, the star shrinks in volume because of the
degenerate matter in it. At a little better than 1.4 times the mass of
the sun--our sun, I mean: Old Sol--the star would theoretically collapse
to a point.

"That has almost happened in this case. The actual limit is when the
star has reached the density of a neutron, and this star hasn't
collapsed that far by a long shot.

"But that star is only forty kilometers--_or less than twenty-five
miles_ in diameter!"

It took nearly two hours of careful juggling to get an orbit which
Arcot considered reasonably circular.

And when they finally did, Wade looked at the sky above them and
shouted: "Say, look! What are all those streaks?"

Arcing up from the surface of the dull red plain below them and going
over the ship, were several dim streaks of light across the sky. One of
them was brighter than the rest, a bright white streak. The streaks
didn't move; they seemed to have been painted on the sky overhead,
glowing bands of unwavering light.

"Those," said Arcot, "are the nebulae. That wide streak is the one we
just left. The bright streak must be a nearby star.

"They look like streaks because we're moving so fast in so small an
orbit." He pointed to the red star beneath them. "We're less than twenty
miles from the center of that thing