[vsnet-chat 113] Re: Bright variables in the LMC

[Mati Morel <morel@ozemail.com.au>]

At 10:07 PM 2/17/97 -0700, you wrote:
>     The apparent distance modulus of the LMC is nearly 19.0.  So the
>luminous Cepheids (absolute magnitudes something like -5 to -7) are quite
>bright, with V ~12-14.  The luminous M supergiants will have absolute
>magnitudes in V of about -4, so will appear at mag. or so.  These ranges
>are very much brighter than the stars being surveyed the MACHO group,
>who are looking down at mag. 17 and fainter.
>     The luminous hot stars have been pretty well surveyed in the Clouds
>by Stephenson and others, but I do not know about the bright cool stars.
>Someone like Mati Morel should know.
>
>\Brian Skiff  (bas@lowell.edu)
>
>
        M supergiants generally appear in large numbers at about V 12.5-13.
Some extreme examples may be as bright as 11.6V.  B-V indices are generally
around +1.9-2.2.
        Roberta M. Humphreys published a fine study of LMC M supergiants
in Astrophys. J. Suppl. 39,389-403 (1979).  Many of the stars observed by
her showed some  small-range variability (0.2 or 0.3 mag in V), and they
appear in the GCVS, vol. 5 in the list of LMC variables.
        B.E. Westerlund et al published extensive lists of M giants and
probable M supergiants in the LMC. See Astron. Astrophys. Suppl. Ser.
43, 267-295 (1981).  Case has also published surveys.
        Westerlund has also published lists of carbon stars in the LMC,
but these stars are at least a couple of mags. fainter in V than the
M supergiants.

Regards,
Mati Morel

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