COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                     Number 3113


                                      Konkoly Observatory
                                      Budapest
                                      27 November 1987

                                      HU ISSN 0374-0676



                A REMARK ON TV CYGNI

  My attention was drawn to this star by the two discordant spectral class
data given in the General Catalogues of Variable Stars 1963 and 1985: MO in
the main table (source not specified) and GO in the remarks (according to
Metik, 1960). A study of literature yielded the following results:

  1. The announcement of variability of BD +46 2970 = TV Cyg (Kohl, 1900)
is based on a misunderstanding. Kohl compared his visual impression with the
chart of Williams (1900), which had been drawn according to the photographic
(blue-sensitive) aspect and which naturally shows this reddish star much
fainter than it looks visually.

  2. A similar error is due to Metik (1960). In his table the wrong 
identification of star +46d2 of figure 16 (chart 9) with BD+46 2970 is excusable,
because on his photographic material the true BD +46 2970 - just visible
1.5 minutes of arc southwest of +46 2 near the edge of the reproduced area
- is distinctly fainter than the latter.

  3. Conclusion: As supposed also by several photometric observers BD+46 2970=
TV Cyg is not variable with high probability.
Vyssotsky and Balz (1958) gave the spectral type K2, while Gaposchkin (1939)
assigned a spectral type of M to this star.


                               W. WENZEL

                          Sternwarte Sonneberg
                      Zentralinstitut fur Astrophysik
                      der Akademie der Wissenschaften
                                der DDR



References:

Gaposchkin, S., 1939, Harvard Ann. 108, 6 [BIBCODE 1939AnHar.108....1G ]
Kohl, T., 1900, Astron. Nachr. 154, 13 [BIBCODE 1900AN....154...13K ]
Metik, L.P., 1960, Izv, Krymskoj Astrofiz. Obs. 23, 60 [BIBCODE 1960IzKry..23...60M ]
Vyssotsky, A.N., and Balz, A.G.A., 1958, Publ. Leander McCormick Obs. Virginia
       13, II, 118
Williams, A.S., 1900, Astron. Nachr. 152, 77 [BIBCODE 1900AN....152...77W ]