[vsnet-chat 5500] Re: [vsnet-outburst 4497] V601 Sco: potential identificationproblem

["Berto Monard" <LAGMonar@csir.co.za>]

Hi interested readers,

Some of you might remember the case of AF Sco. That one and other
assumed CVs were later redefined as red LPVs thanks to the monitoring
eye of visual observers. 
Later, the same happened to V2323 Sgr. 

NSV 8383 (V877 Ara) was rediscoverd via outburst detections and found
to be at a different position from the published one.

I could be wrong but that's what I think:

1. that a number of those CVs (sometimes even reported as N: ) were not
properly followed up or astrometrically dated. Later efforts to rectify
that were not always successful.
Probably this is established knowledge..
but then:
2. under the assumption that this were (had to be?) CVs, a search for
blue stars around the vague positions must have been conducted and
(eureka!) the true counterparts were found. USNO catalogues are very
useful for this. In rich MW fields it is even a matter of which of those
blue objects might be the 'one'. 
3. this works well and the literature is enriched with those
finds....until such time that the 'CV' shows up again, in striking
colour: blue or.... red.

It's not a matter of putting blame, it is just a natural process and in
the case of V877 Ara I was actually the culprit pointing the 'new'
position at a blue 17th magnitude star (from USNO) after a visual
detection, while in fact the true V877 Ara later showed up (on mine and
other's CCD cameras) to be very close by but somewhat to the South of
that position, to a faint obscure star of magnitude 19.5 in quiescense.
At least it was blue in the active state.  

V601 Sco? 

who's next?


Regards,


Berto Monard
Pretoria


>>> Taichi Kato <tkato@kusastro.kyoto-u.ac.jp> 09/10/02 10:19AM >>>
V601 Sco: potential identification problem

   Regarding the recent detection of a brightening of V601 Sco by Rod
Stubbings, and rather negative CCD observation by Berto Monard:

   After a discussion with Rod Stubbings and Berto Monard, it has
become
evident that V601 Sco has not been yet unambiguously identified in the
past literature.  My comment follows.

===

    It is possible that Rod actually observed the "true" brightening
of
V601 Sco.  The identification on Downes CV atlas comes from Vogt and
Bateson,
who simply selected a "blue" object near the originally reported
position.
It is possible that the true V601 Sco is a red variable, which may be
now
rising.

    Please take a few snapshots (not necessarily nightly), Berto, with
short
exposure times to avoid saturation.  This observation could reveal the
true identity of V601 Sco.

Regards,
Taichi Kato

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