COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 347


                                Konkoly Observatory
                                Budapest
                                1969 April 30


     A SEARCH FOR THE VARIABLE OPTICAL COMPONENT
                OF THE PULSAR NP0527

         The pulsar NP0527 is within about 1deg of the pulsar
NP0532 in the Crab Nebula and has a similar integrated
electron density.  As a result it has been suggested^1 that
NP0527 was ejected from the Crab Nebula. The optical
variation of NP0532 has been reported^2.
         A blink search for a high velocity object at the
position of NP0527 was made. Using a blue plate taken on
8 March 1969 on the 26" at Herstmonceux and a copy of the
blue POSS print, the search was complete down to about 18.5m,
and an area twice the radio error box covered. Since the
proposed proper motion is 4.8" per year, the motion of the
pulsar over the seventeen years would be easily detectable.
No such object was found. If the pulsar was ejected from
the Crab, its average luminosity must be less than this
limit.


                              A.J. PENNY


Royal Greenwich Observatory, 23rd April, 1969


1 Reifenstein, III, E.C., Brundage, W.D. and Staelin, D.H.,
  Phys. Rev. Lett., 22, 311, 1969 [BIBCODE 1969PhRvL..22..311R ]
2 Cocke, W.J., Disney, M.J. and Taylor, D.J., Nature, 221,
  525, 1969  [BIBCODE 1969Natur.221..525C ]