[vsnet-chat 5549] Re: [AAVSO-DIS] The curious case of BD+59 224

[DWest61506@aol.com]

Brian:
To try to shed some light on the confusion surrounding the nature of BD+59 224, I imaged the field last night with B,V, and Rc filters.  My purpose was not to provide highly accuracy photometry and astrometry (as you can see, my error bars are large) but to help resolve the spectral type question for BD+59 224.  I hope this helps.

Regards,
Doug West
http://hometown.aol.com/dwest61506/index.html

This URL goes to the field of BD+59 224 http://members.aol.com/dwest61506/page31.html .

Astrometry of field:
GSC 4030:591     01 17 26.82 +60 22 11.6
GSC 4030:149 = BD+59 224     01 17 19.08 +60 23 04.1
Positions based on 8 GSC 1.1 stars.  Estimated error 0.5".

Differential Photometry (without color transformation):
GSC 4030:591  V=10.28 +/-0.06, B-V=-0.06+/-0.15, V-Rc=0.23+/-0.07
BD+59 224  V=9.38+/-0.06, B-V=1.31+/-0.15, V-Rc=0.97+.-0.07

Comparison stars for photometry:
GSC 4030:427  B=11.57, V=10.48, Rc=9.88;  B&V from Tycho 1, Rc from conversion formula below.
SAO 11690 B=9.59, V=9.47, Rc=9.39, B&V from SIMBAD, Rc from conversion formula below.

V-Rc from B-V conversion formula http://members.aol.com/dwest61506/page32.html .
Equipment: 0.2 m SCT + ST-9E CCD + filters, three 30 second exposures per filter


In a message dated 9/27/2002 5:46:21 PM Central Standard Time, Brian.Skiff@lowell.edu writes:

    While cleaning up a spectral-survey catalogue file, I recently came
across the strange case of BD+59 224.  This red star has appeared in several
low-dispersion surveys with quite conflicting classifications.  Basic data are:

BD+59 224 = IRAS 01141+6007 = DO 24182 = BSD 8-747

1 17 19.12  +60 23 03.5 (J2000, Tycho-2)

     In the Bergedorf spectral survey, the star is described as "peculiar",
with the remarks saying that the spectrum appears composite of types F2 and
G5; at least one helium line is strong, while the CaI K line, H-delta, and
the G band are all weak; the intensity distribution is like that of an
unreddened G5 star.  The BSD, by the way, identifies the star erroneously
as BD+59 225, which is a neighboring (blue) star, and this typo persists in
later literature.  (The SIMBAD IDs for the two have been corrected.)
     About the same time (late 1930s), the Dearborn catalogue shows it simply
as type K5 without remarks.
     In 1960 Brodskaya (1960IzKry..24..160B) records it in her survey as
type O, also with no other remarks.
     Finally, Sjogren (1964ArA.....3..339S) gave BV photometry of V = 9.85
and B-V = 1.62, and remarks that the spectrum is like a planetary nebula
with many emission lines.
     All these descriptions are from relatively low-dispersion blue-light
objective-prism plates.  The IRAS fluxes are that of a typical 12-micron
source, indicating a luminous, cool star with silicate shell.  The Tycho-2
photometry corrected to the standard system gives V = 9.47 and B-V = 1.48;
the nominal errors are small, suggesting no marked variability.

     As best I can tell there is no recent study of the star.  Just as a
guess, this is probably a VV Cep-type massive binary involving a K- or M-type
supergiant and a B-type star (possibly Be or B[e]?) that gives rise to the
emission lines, which are possibyl transient/variable.  A similar massive
binary like epsilon or zeta Aurigae might better fit the Bergedorf spectrum
description.  A simple U-B color might decide the case, but a spectrum in
the standard blue MK wavelength range would be more diagnostic.

\Brian

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