COMMISSION 27 OF THE I. A. U.
                    INFORMATION BULLETIN ON VARIABLE STARS
                                 Number 2497

                                                        Konkoly Observatory
                                                        Budapest
                                                        23 March 1984

                                                        HU ISSN 0374-0676





        NEW LIGHT ELEMENTS AND TIMES OF MINIMUM FOR AO CAMELOPARDALIS


   AO Camelopardalis (BD+52d0826) is a Ursae Majoris type system which
was discovered by Hoffmeister (1966). Milone et al., (1982) conducted a
brief period study which was the first detailed work done on this system.
They obtained four times of minimum and a set of light elements.
   This star was observed on four nights during the winter of 1984 using the
42-cm reflector of the Morgan-Monroe Station of the Goethe Link Observatory.
The photometer employs a 1P21 photomultiplier tube cooled with dry ice, and
Johnson B and V filters. Differential measurements were made using BD+52d0835
as a comparison star and BD+52d0822 as a check against any variability in the
comparison star.
   The Hertzsprung method was used to determine times of minimum light
from the observations in each filter. These results were averaged and
are presented in Table I.

              TABLE I
HJD             Min.        (O-C)
2445732.6076    II         -0.0002
2445738.5463    II          0.0000
2445745.6402     I          0.0006
2445752.5676     I         -0.0004


   The residuals presented here were formed from a new set of light
elements which were derived from a linear least squares fit to these
observations. The new elements indicate a possible period change from
the period determined by Milone, and are:


        Min.I = 2445745.6396 + 0.0329921d E.
                         +-2         +-7

Complete light curves were obtained in both colors and the curves of normal
points are shown in Figure 1.


                               [FIGURE 1]


   A complete analysis of this system, including a period study and the
application of the Wilson-Devinney method of solution to this system will be
published elsewhere. The authors would like to express their appreciation to
Mr. Danny R. Faulkner and Dr. Stuart L. Mufson for their assistance on this
project.





                ERNEST E. EVANS III
                DANIEL H. GROSSOEHME
                EDWARD J. MOYER Jr.
                Astronomy Department
                Swain Hall West 319
                Indiana University
                Bloomington, IN 47405 U.S.A.



References:
Hoffmeister, C. 1966, Astronomishe Nachrichten, 289, 1. [BIBCODE 1966AN....289....1H ]
Milone, E.F., Piggott, D.H., and Morris, S.L. 1982, J.R.A.S.C., 76, 90. [BIBCODE 1982JRASC..76...90M ]