Date: Fri, 4-Nov-83 03:47:00 EST
Posted: Fri Nov 4 03:47:00 1983
Date-Received: Tue, 8-Nov-83 21:37:00 EST
From: Ron Goldman
n054 1329 31 Oct 83
c. 1983 N.Y. Times News Service
In 1976 the Soviet Union's Crimean Astrophysical Observatory found
that the surface of the sun is heaving up and down every 160 minutes.
''The interpretation of this phenomenon,'' it reported, ''seems to
cause much theoretical difficulty.'' More recently, astronomers have
been puzzled by the enigmatic nature of an extremely powerful
celestial source of gamma rays called Geminga, which also have a
Now, George Isaak of the University of Birmingham in England has
proposed that Geminga causes the solar oscillations. Geminga is
believed to be the closest neutron star to the solar system. Isaak
argues that if, like many other stars, Geminga is in a tight orbit
around some companion body, the pair might radiate gravity waves
sufficiently powerful to jostle the core of the sun.
Einstein's general theory of relativity predicts the existence of
gravity waves, but they have never yet been convincingly detected.
The core of the sun, with a density of 30 tons per cubic foot, should
respond to such waves far more efficiently than the metal cylinders
used in earth-based detection efforts.
According to the October 20 issue of Nature, Philippe Delache of
France's Nice Observatory and his colleagues have examined five
months' worth of gamma ray emissions from Geminga, recorded by the
satellite COS-B over a seven-year period. They report a 160-minute
variation and also note that tiny earth tremors reach a maximum every
160 minutes, as though the earth were also responding to the gravity
As noted by Nature, however, there are several difficulties with
such proposed links. When two massive bodies are circling one another
every 160 minutes, as indicated by the gamma ray variations, gravity
waves should be emitted by each object. The pair would therefore
radiate one every 80 minutes.
A research group at the University of Rome, led by Eduardo Amaldi,
has used suspended bars of metal to record oscillations that could be
coming from the core of the Milky Way Galaxy, but they are not yet
persuaded the cause is gravitational. Evidence for gravity waves from
the galactic core was reported a number of years ago by Joseph Weber
of the University of Maryland, a pioneer in such observations, but
was never generally accepted.