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IAUC 3535: 1980q; R Aqr

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                                                  Circular No. 3535
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM     Telephone 617-864-5758

     Rolf Meier, Ottawa, Ontario, reports the discovery of a comet
(0.4-m f/5 reflector, 56 x).  Representative observations follow:

     1980 UT          R. A. (1950) Decl.     m1     Observer
     Nov.  6.11111   18 06.2     +42 09     10.5    Meier
           7.00000   18 05.2     +41 38      9.8    Morris

R. Meier (Ottawa, Ontario).  Object diffuse with condensation.
C. S. Morris (Harvard, MA).  0.25-m reflector.

     G. H. Herbig, Lick Observatory, writes: "The arcs of emission
nebulosity extending to ~ 70" from the symbiotic long-period variable
R Aqr are, according to a 1944 note by Baade, in slow expansion
at a rate suggesting ejection from the star ~ 600 years before
that time.  There is also complex emission nebulosity within ~ 15"
of the star.  On Lick 3-m direct plates of 1960 and 1970 its brightest
features are two semistellar knots at separation 8", p.a. 23o
(Knot A) and 13", 22o (Knot B) and a remarkable loop of nebulosity
4" in diameter at ~ 8", 177o.  Plates taken last month, when the
variable was near minimum, show that a striking change has taken
place in this inner nebulosity since 1970: a brilliant emission jet
or spike [so called by Wallerstein and Greenstein (1980, P.A.S.P.
92, 275), who in 1977 saw what must be the same feature] now extends
from very near the star image to ~ 10" in p.a. 22o and has
obliterated Knot A.  In H-alpha the surface brightness of this spike is
now ~ 8 times that of Knot B, the next brightest point in the nebula.
In fact, the spike is quite conspicuous visually at the 3-m.
Lines of [O I], [N II), He I, [S II], [S III] and H-alpha in the spike
give a radial velocity of -64 to -75 km/s, depending on the ion,
while Knot B is at ~ -25 km/s, near the stellar velocity.  The
1960-1980 direct plates confirm the slow enlargement of the outer
structure.  Provisional measurements show that the loop and Knot B are
moving away from the star at 0".05 to 0".08 per year, corresponding
to cross velocities of 50 to 80 km/s at 200 pc.  At these velocities,
the loop and Knot B would have left the star about the year
1800.  The present position of the spike and its absence on the
1970 plate can be reconciled with uniform radial motion (rather
than by appearance in place) by assuming a more recent ejection,
but with a tangential velocity of at least 300 km/s."

1980 November 7                (3535)              Brian G. Marsden

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