COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 766

                                       Konkoly Observatory
                                       Budapest
                                       1973 February 8

      SUSPECTED LONG-PERIOD VARIABLE NEAR NGC 2368

The infrared object IRC-10162 (1950:7h18m37s-10d16.6') has
been suggested as a member of the loose open cluster NGC 2368
by Cohen (1971), who has published finding charts of the field.
Low dispersion (495 A mm^-1) near-infrared (6500-9000 A) image
tube spectra have recently been obtained of IRC-10162 with the
1 meter reflector at the Wise Observatory. Those observations
(summarized below) indicate that the star exhibits spectral
changes which might be expected of a long-period variable:


   U.T. Date         J.D.          Spectral Type
27 November 1972   2441649.5           M7
13 January  1973   2441696.4           M9


The spectral types were estimated from the strengths of the near-
infrared VO bands (heads at 7400 and 7900A). Standards used for
comparison were o Cet at minimum light (M9), RT Vir (M8), and Z Cnc (M6).
The IRC catalogue (Neugebauer et al. 1969) records three observations 
of IRC-10162 over an interval of approximately one year. During 
this time a DeltaI = 0.56m (effective wavelength of I = 8400A) was
observed. Both the spectroscopic and photometric observations 
indicate that IRC-10162 is a variable star. We suggest that it is
most likely a long-period variable.
The integrated magnitude of NGC 2368 is 11.8 (Collinder 1931).
According to Cohen (1971) there is no photometry, however, available 
for individual cluster members. From a cursory inspection  of
Cohen's finding charts, IRC-10162 appears to be among the brightest
stars of the cluster which is in accord with the hypothesis that
the alleged long-period variable is a cluster member. Because there
are so few long-period variables known to be members of clusters, we
urge that further observations be made of IRC-10162 to confirm type
variability as well as cluster membership.
   We acknowledge the wise observatory of Tel-Aviv University and
the Smithsonian Research Foundation Grant SFC-0-3005 for the use
of their facilities at Mitzpeh Ramon, Israel.


January 31, 1973    S. WYCKOFF and P. WEHINGER
                       Wise Observatory
                     Tel-Aviv University, Israel





References:

Cohen, M., 1971, Astrophys. Letters, 9, 95. [BIBCODE 1971ApL.....9...95C ]
Collinder, P., 1931, Annals Obs. Lund, 2. [BIBCODE 1931AnLun...2....1C ]
Neugebauer, G., and Leighton, R.B., 1969, Two Micron Sky Survey:
          A Preliminary Catalog (NASA, SP-3047). [BIBCODE 1969tmss.book.....N ]