[vsnet-newvar 1501] Re: [vsnet-chat 5402] CGCS 2792

[jg <jg@jgws.freeisp.co.uk>]

Well, it's F0 in the PPM and SAO.

If I remember rightly these two catalogues get their spectral types from
the AGK astrometric catalogues, which then leads to the question of the
provenance(s) of the spectra in those.  (I don't think it's a HDE star).

A quick check suggests that this spectral type of F0 probably comes from
Boss's General Catalogue of the 1930's, again an astrometric compilation
and not a primary spectral type source: ie where'd Boss get it?

A spectral class F carbon star... ...circumstantial evidence for RCB
star.

This is of course another layer of potential confusion added from the
catalogue data.

Regular large amplitude variation, of the Mira kind, seems precluded by
the USNO NOFS plate archive blue and red images, temporarily available
via here:-

http://vsnet.nofs.navy.mil/tmp/fchaaaqFa_fch.html

Cheers

John

JG


Taichi Kato wrote:
> 
> Re: [vsnet-chat 5402] CGCS 2792
> 
> > In the April issue of Communique by the Southern CCD and Photometry Group,
> > there was a note on this carbon star.
> > Observations by Colin Henshaw and Albert Jones suggest this is a variable
> > star. Although the reported magnitudes (9.1-10.0) are far from the V
> > maeasures (V= 8.36, B-V= 4.04 from the GCPD and 8.35 from Tycho-2) and
> > remind me of the UY Centauri case, it is very important to keep track of
> > this carbon star since the probbilities of this being variable are high.
> > My first observation a couple of weeks ago gives 8.1 suggesting the star is
> > brighter than the catalogued 8.36 value.
> 
>    Identifications of CGCS 2792:
> 
> GSC8961.1219 103417.94 -624239.5 (2000.0)  7.56 6 N
> GSC8961.1219 103418.01 -624239.6 (2000.0)  8.17 6
> USNO0225.08847278 103417.982 -624239.59 (2000.0)  7.9 99.9
> IRAS10325-6227 103231.6 -622706 (1950.0)
>     F12=63.08  F25=19.05  F60=4.78  F100=20.89L
>     VAR= 0 LRS=45
>     blue, 11micron (SiC) emission, strength=5
>     VII: variable star with more evolved C-rich circumstellar shell
> 103417.6 -624243 (2000.0) CD-62.466 8.5
> 103417.7 -624236 (2000.0) CGCS_J1034-6242 (CGCS2792) 12.8 8.2 4.0 N(Thack49)
> 103417.7 -624237 (2000.0) CS2792 12.8 8.2 4.0 CD-62.466
> 103417.7 -624237 (2000.0) IRAS10325-6227 62.450 19.430 4.916 21.340L 0% 6(LRS)
> 103417.7 -624237 (2000.0) SSC10325-6227 62.450 19.430 4.916 21.340L
> 103417.9 -624238 (2000.0) SAO251015 99.9 8.6 F0
> 103418.0 -624239 (2000.0) MSX5C_G287.9294-03.9043 -28 141 71 57 29 19 V(%):-:1:2:1:0:3
> 103417.8 -624239 (2000.0) 830EVv TYC8961.1219.1 plx=4.3(12.8)
> 103417.8 -624239 (2000.0) 835 4.51 TYC2-8961.1219.1 (8.83 0.01) (14.13 0.49)
> 
> 103417.9 -624200 (2000.0) G0(V)(Buscombe) V=8.6 - -
> 103417.9 -624200 (2000.0) S(Buscombe) - - -
> 
>    It may be interesting to note that Buscombe gave discrepant spectroscopic
> classifications (S and G0V) to the apparently same star.

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