COMMISSION 27 OF THE I.A.U.
                 INFORMATION BULLETIN ON VARIABLE STARS
                              Number 2947

                                                         Konkoly Observatory
                                                         Budapest
                                                         21 October 1986

                                                         HU ISSN 0374 - 0676


                     NEW DATA ON V503 SAGITTARII

The Lowell Observatory investigators commented concerning the newly-
discovered 
proper-motion star G154-12 (v= 0".32/yr, m_p = 15.2, color class +4)
that "the motion is somewhat uncertain, since the object assumed to be the
first-epoch image is 1.5 magnitudes fainter than the second-epoch images." One
of us (W.P.B.) has recently noted that the position of this object is nearly
identical with that of the apparently unstudied variable V503 Sgr discovered by
Shajn in 1933. She found it to be visible on only 6 out of 23 plates, with a
magnitude ranging from 13.3 to below 14.6 pg.
   During the course of discussion on this object, H.L.G. offered to try to
improve the proper-motion determination by obtaining a third-epoch plate with
an added 23 year epoch. Comparing a plate of G154-12 taken on September 5, 1986
with the first-epoch plate of June 1931, the brightness of the variable was
very similar on the two plates; but the proper motion, under these more
comparable conditions, was found to be only about one-third as large. The
published admonition that the motion originally found was "somewhat uncertain"
is correct; and it was probably due to the fact that the star was 1.5
magnitudes brighter on the second-epoch plates, and being so excessively red, a
large portion of the motion found was due to a radial color-magnitude
displacement.
   On a Burrell Schmidt infrared objective-prism plate the spectral type
appears to be M3 or M4.


     WILLIAM P. BIDELMAN                   HENRY L. GICLAS
     Warner & Swasey Observatory           Lowell Observatory
     Case Western Reserve University       Mars Hill Rd., 1400 W.
     Cleveland, Ohio 44106 U.S.A.          Flagstaff, Arizona 86001 U.S.A.



References :

Giclas, H. L., Burnham, R., and Thomas, N. G. 1964, Lowell Obs. Bull. 6, 109
     (No. 122). [BIBCODE 1964LowOB...6..103G  ]
Shajn, P. 1933, N.N.V.S. 4, 119.