[vsnet-chat 1211] Re: V592 Her: examination of the 1986 outburst data (schmeer)

[Taichi Kato <tkato>]

Re: [vsnet-chat 1210] Re: V592 Her: examination of the 1986 outburst data (schmeer)

Dear Patrick,

> You must have had a very good sky. I can see mag 14.5 stars with my 20-cm
> telescope only under very good conditions (there are, however, quite a lot of
> streetlights around).

   No, these observations were done under bright citylight of Kyoto (even
neglecting the incresing light pollution in these 12 years).  I could
exceptionally rarely see the Mily Way.  The high magnification (I usually
used more than x100 for this 10-cm telescope) and the complete shielding
of stray lights greatly helped.  One of my friends, who also used a
10-cm reflector, could sometimes see 15-16th mag using x200.

> Then you should have been able to see EY Cyg at minimum (about mag 14.7).

   Ideally.  The EY Cyg field looks to crowded for this small telescope,
but I could occasionally perceive DO Dra at minimum (probably at brightest
points og fluctuations).  I recorded mag 15.0 for this field.  Quiscient
U Gem was the borderline.

   For those interested, I select some descrptions for "the Guide to CVs
Observations", written by me (1987-88) in Japanese, intended for telescopes
of 20-cm apertures:

  V792 Cyg: close to EY Cyg; conveniently situated for monitoring.  Outbursts
well within a 20-cm telescope.  Use high magnification to avoid confusion
with the 15.65 mag comparison.

  V868 Cyg: difficult to locate among stars of similar magnitudes.
A challenging, not so faint, object for 15 to 20-cm telescopes.  Carefully
identify the chart against the field.

  V1113 Cyg: short recurrence time confirmed.  Usual maxmimum around 15.0;
needs a rather high magnification to separate from the nearby 13.5-mag star.
Suitable target for a 20-cm telescope.

  V1404 Cyg: despite of the faint cataloged maximum magnitude, it is not
very difficult to catch outbursts using a 20-cm telescope; the pattern of
the nearby stars make identification easy.

  V1504 Cyg: outbursts detectable using a 20-cm telescope.

  V725 Aql (former ID): crowded field.  Comparison with the POSS-based chart
is recommended to identify the object.

  V794 Aql: always seen around 14.5

  V1290 Aql: visibile at mag 15-16.  Continuous monitoring for outbursts
is needed.

  BZ UMa: quiescence can be observed with a 15-cm telescope.  Outbursts
with amplitude of 1-2 mag are rarely observed contrary to litertures.

  CI UMa: the 1998 Jan. outburst looks like a superoutburst.
Minimum reachable?

  FO And: frequent outbursts; observable by 15-cm telescopes.  Minimum
looks brighter than catalogued, barely detected using 20-30 cm telescopes.

  FS And: detectable using 20-30 cm telescopes; nearby 15-mag star interferes.

  KW And: field very easy to locate, 15-16 mag stars rather easily seen
with a 20-cm telescope.

 ...

> Do you have more information about VX For (max/min brightness, outburst dates)? 

   12.5-(22p  Announced in IAUCs.

> V4338 Sgr = Nova Sgr 1990, isn't it? How probable is the DN classification?

   I'm not sure of the classfication, as once discussed in this list; the
object apparently faded below 20-th mag.

Regards,
Taichi Kato

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp