COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                      NUMBER 563

                                Konkoly Observatory
                                Budapest
                                1971 June 26


         VARIABLE 14 IN THE GLOBULAR CLUSTER M5

      This note is to call attention to an interesting
feature of Variable 14 in the globular cluster M5 = NGC 5904
(Bailey, 1917). The period of this star has been given by
Coutts and Hogg (1969) as 0.49 days, a period characteristic
of an RR Lyrae variable. However, from the UBV colors
of the star obtained by Arp (1962, where it is star II-51)
its position in the H-R diagram of the cluster is not in
the region of the RR Lyrae variables but rather somewhat
redder and brighter, in the neighborhood of the Asymptotic
Branch. This has recently been confirmed by measurements
with the David Dunlap Observatory intermediate-band photometric 
system from which were determined an effective
temperature of the star of around 5200deg and a surface gravity 
of Log g = 0,8 in CGS units (Osborn, 1971). These data
would be more consistent with the star being a W Virginis
type variable, and in view of the comments concerning the
period by Coutts and Hogg (1969) and Bailey (1917) it is
possible that the period is in error. In any event, however
the unusual position in the H-R diagram makes the star an
interesting candidate for further study.
                               

Proyecto de Astrofisica         WAYNE OSBORN
Apartado 264
Merida, Edo. Merida
Venezuela


[References]

Arp, H. (1962) Astrophys. J. 135, 311. [BIBCODE 1962ApJ...135..311A ]
Bailey, S.I. (1917) Harvard Ann. 78, 99. [BIBCODE 1917AnHar..78...99B ]
Coutts, C.M. and Hogg, H.S. (1969) Publ. David Dunlap
      Observatory 3, 1. [BIBCODE 1969PDDO....3.....C ]
Osborn, W.H. (1971) Positions of Globular Cluster Stars in
      the Physical H-R Diagram. Ph.D. Thesis, Yale
      University. [BIBCODE 1971PhDT.........1O ]


                     [See IBVS 598]