COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 2601

                                  Konkoly Observatory
                                  Budapest
                                  12 October 1984

                                  HU ISSN 0374 - 0676




      A POSSIBLE BL HERCULIS VARIABLE IN CETUS



   The Maria Mitchell Observatory is conducting a search
for variables in the region of the South Galactic Pole.
Blinking pairs of plates revealed one definitive variable.
The coordinates are 00h 45m 04s, -18d 08' 51" (1900).
   The star appears on approximately 40 plates of the
Maria Mitchell collection spanning the years 1980 (when
the observatory began photographing the field) to 1984.
Using the data from these plates, a Lafler-Kinman (1965)
period search was run for the period range .25 day to 10
days. This revealed a period for the variable of 1.137695
-+ .000035 days. The mean error was determined by the method
of Belserene (1983). The epoch of maximum is JD2445593.72
The rising branch occupies 0.13 of the cycle.
   The range is 13.9 to 14.9, photographic, according to
provisional magnitudes for the sequence stars, which are
shown in the find.finding chart, Figure 1. The magnitudes are
based on a rather unsatisfactory photographic transfer from
photoelectric magnitudes in NGC288, which is 9d to the south.

                        Figure 1. Finding chart, 25' x 25',
                        with north up and east to the left.
      [FIGURE 1]
                        Star A is SAO 147459. Provisional
                        m_pg for a, b, and c are 14.1, 14.7,
                        and 15.4, respectively.

Both the high galactic latitude (-80d) and the large amplitude
imply that this may be a variable of the BL Herculis type.
Secondary humps, which are characteristic of these short
period Population II Cepheids (Kwee 1967) have, however,
not been observed.

   It would be interesting if observatories with plate
archives would study this star for the rapid period changes
which are expected in the BL Her stage of evolution. 
(Christianson 1984, Gingold 1976).
   I would like to thank Dr. Emilia P. Belserene for her
assistance and guidance. This work was funded by NSF AST
8320491, and I thank the National Science Foundation for
support.

                      JOAN FRANCES WAUGH
                   Maria Mitchell Observatory
                   Nantucket, Mass. 02554 U. S. A.





References:

Belserene, E.P. 1983, Microcomputers in Astronomy, R.M. Genet,
    ed., Fairborn Observatory, 229. [BIBCODE 1983mca..symp..229B ]
Christianson, J. 1984, Journ. Am.Assoc.Var.Star Observers 12,
    in press. [BIBCODE 1983JAVSO..12...54C ]
Gingold, R.A. 1976, Astrophys. Journ. 204, 116. [BIBCODE 1976ApJ...204..116G ]
Kwee, K.K. 1967, Bulletin of the Astronomical Institutes
    of the Netherlands 19, 260. [BIBCODE 1967BAN....19..260K ]
Lafler, J. and Kinman, T.D. 1965, Astrophys. Journ.Sup. 11, 216. [BIBCODE 1965ApJS...11..216L ]