COMMISSIONS 27 AND 42 OF THE IAU 
             INFORMATION BULLETIN ON VARIABLE STARS 
                          Number 3787 
 
                                           Konkoly Observatory 
                                           Budapest 
                                           8 October 1992 
 
                                           HU ISSN 0374 - 0676 
 
 
                  ON THE GENUINE V2045 OPHIUCHI 
 
 A star at the 1950 position of 16h48m37.0s -6d9'39" was announced 
by Nassau et al. (1964) as a new Mira-type variable, on account of 
its objective-prism spectrum which indicated an M-type giant showing 
Hdelta in emission stronger than Hgamma. The only brightness value 
known up to now has been Nassau's mpg=12.1m from a Cleveland plate, 
and despite of this meagre data the object gained entry to the GCVS as 
V2045 Oph. 
 
 Because of our very fragmentary knowledge of the star we tried to 
investigate it on photovisual plates of the Sonneberg Sky Patrol 
(taken between 1963 and 1991 mainly by H. Huth and B. Fuhrmann), since 
it must be avoided that Nassau's observation one day will be taken for 
a single burst of some strange eruptive object. This danger proved to 
be even larger than we originally thought because the object indicated 
on the chart of Nassau et al. (l. c.) is neither red nor 
conspicuously variable on our plates. 
 
 However, it turned out that approximately 3.7' to the south of 
indicated star a typical Mira star exists. It is depicted just inside 
of Nassau's chart (22 mm apart from the eastern and 2 mm from the 
southern margin) and can also easily be identified by its red colour 
on the POSS O and E sheets, where it is obviously near minimum phase. 
We have hints for 7 maxima on our plates. Their dates yield a period 
of roughly 304d and a maximum brightness of 12.0m pv (roughly equal 
to the brightness of star A of our chart), the minimum being below the 
threshold fainter than about 13.5m pv. On our blue sensitive plates 
taken simultaneously with the photovisual ones the star appears in 
maximum slightly brighter than 14.0m. 
 
 Doubtless we have observed the genuine M5e Mira-type star, and the 
chart of Nassau et al. (l. c.) is wrong. Also the position given by 
these authors fits our object. It is very probable, therefore, that at 
JD 243 7111 they met the star during an extraordinarily bright 
maximum. On our chart the variable is indicated by its designation 
and the wrong star by two strokes. 


                            [FIGURE 1]

 
 We thank Mr. D. Bohme for directing the attention to this star. Part 
of the work has been supported by funds of the Bundesministerium fur 
Technologie under contract no. 05-5S0414. 
 
 
 
                          W. WENZEL 
                          Sternwarte O-6400 Sonneberg, FRG 
 
                          E. RUDOLPH 
                          O-6900 Jena, Jansonstrasse 17, FRG 
 
 
 
Reference: 
 
Nassau, J. J., Stephenson, C. B., Caprioli, G.: 1964, Astrophys. J. 
  139, 864  [BIBCODE 1964ApJ...139..864N ]