COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                    Number 2039

                                Konkoly Observatory
                                Budapest
                                1981 November 10

                                HU ISSN 0374-0676





       THE IDENTIFICATION OF OI 090.4 AND CSV 1180



The proximity of the BL Lacertae object OI 090.4 to the
suspected variable 1180 (=Ross 200 = Prager 512) has been
noted earlier by one of us (Baumert 1978). In fact,
Baumert suggested that the coordinates given by Ross (1927)
may be in error and that Ross actually observed a brightening
of OI 090.4 in 1915 and 1927.
The arguments for this hypothesis were 1) the difference
of only +1.9s in right ascension and +0.64' in declination
between CSV 1180 and OI 090.4; 2) the comment by Sandig
(1947) that he found no object at Ross' position that varied
by more than 0.15 mag; 3) the closest star to the position
cited by Ross was at best nearly 3 mag fainter than those
quote d by Ross; and 4) OI 090.4 was brighter than normal
in 1915 and 1927.
Ross' original plates have been searched in order to confirm
or deny the hypothesis. A careful inspection of the plates
reveals that the only object in the region that varies
significantly is OI 090.4, thus confirming the identity of
CSV 1180 and OI 090.4.

The magnitudes cited by Ross are also in error. Cudworth,
using the photometric sequence of Baumert (1978), determined
m_pg ~14.2 for 1915 March 12 and 15.5 for 1927 Jan. 5. The
error for each estimate is +-0.2 mag. These magnitudes are
consistent with those obtained by Baumert (1980) who 
determined a magnitude of 14.7 for 1915 Feb. 10, 15.3 for 1927
Jan. 7, 15.4 for 1927 March 1, and 15.6 for 1927 March 8.
In closing, it is noted that the labels A and B are reversed
in Figure 1 of Baumert (1978). They are labelled correctly
in Baumert (1980).





                     JOHN H. BAUMERT
                     Computer Sciences Corporation
                     Space Telescope Science Institute
                     Homewood Campus
                     Baltimore, Md.   21218   U.S.A.


                     KYLE CUDWORTH
                     Yerkes Observatory
                     Williams Bay, Wisconsin 53191
                     U.S.A.





References:
Baumert, J. H. 1978, Information Bulletin on Variable Stars No. 1410.
Baumert, J. H. 1980, Pub. Astron. Soc. Pacific 92, 156. [BIBCODE 1980PASP...92..156B ]
Ross, F. E. 1927, Astron. J. 37, No. 882, 155. [BIBCODE 1927AJ.....37..155R ]
Sandig, H.-U. 1947, A. N. 275, 37. [BIBCODE 1947AN....275...37S ]