[vsnet-id 712] Identity of QR Nor

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

QR Nor is listed in the GCVS as a Mira variable (range 13 -17p, spect. Me),
with a rough 1950 position which places it only 6 seconds of RA preceding SS
Nor (M, 12.-2 - <16p) and slightly north.  In the late 1980s I was working
on SS Nor, and I consulted Rob McNaught about QR Nor. He proposed a red star
just S of SS Nor as the best candidate. A precise 1950 position was
published in IBVS 4037 (1994), and SIMBAD adopts this position as (2000)
16h13m20.1s -59°47'30".
Lately, however, I have had doubts about this star. A check of all available
digitized sky survey images, and other available images, show _no_ variable
at this spot.  SS Nor, however, is quite obvious - variable from image to
image.  A check of the paper trail may help in solving this problem.
Luyten (1938) announced the variability of a star at (1900)
6h4m48s  -59°30', called HV 8848. For a long time it was listed as suspected
variable (CSV 2591).  In 1976 Stephen and Sanduleak reported the spectrum of
CSV 2591 as "Me". They gave the position as (1900) 16h4.8m -59°29'.  In 1978
it received the name QR Nor, Mira variable 13-17p (63rd Namelist of Variable
Stars, IBVS 1414).  There is a star whose Tycho-2 data is a good match for
this data.  GSC 8722_00719, position at equinox 1900 : 16h4m47.7s -59°28'5"
. According to Tycho-2,  V=11.32, and B-V = +1.53+/-0.30.  According to
color and position it is a plausible match for QR Nor.
GSC2.2 gives (2000) 16h13m16.720s  -59°43'38.56"    Mag (Bj) =13.34

Unfortunately a study of available digitized plates shows _no_ large
amplitude variations. It seems fairly steady. Has Luyten confused his
variable with nearby SS Nor?  [SS Nor = GSC 7861_01088 = HV3959, (2000)
16h13m21.888s -59°46'56.64",  position taken from IBVS 5298, but no mention
of QR Nor].

The position and spectrum/color data seem to point to GSC 8722_00719 as QR
Nor, but there is no Mira type variation,
unless someone can prove me wrong.  SS Nor is the only proven Mira type in
the vicinity.

Regards,
Mati

morel@ozemail.com.au

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