New deeply eclipsing SU UMa star TmzV85!! = IY UMa

Superhump and eclipses, observations by the VSNET Collaboration team: Makoto Uemura, Taichi Kato, Katsura Matsumoto, Lasse Teist Jensen, Rudolf Novak, Denis Buczynski, Tonny Vanmunster, Marko Moilanen, Arto Oksanen, Timo Kinnunen, Jochen Pietz, Brian Martin, Lew Cook

Superhump and eclipses in detail

(vsnet-alert 4027)

TmzV85 (UG:)

TmzV85  20000108.463  176C  Scp
TmzV85  20000113.509  140C  Scp
TmzV85  20000114.512  140C  Scp
TmzV85  20000115.440  140C  Scp 
Sequence:   VSNet (V magnitudes) 
Instrument: IRO (0.5-m RCT + AP-8)
Only one previous outburst of this cataclysmic variable has been recorded (cf. vsnet-obs 18078 below).
USNO-A2.0 data for TmzV85:
R.A. 10h43m57.097s  Decl. +58o07'33.20" (J2000.0) r= 16.2, b= 16.4

Arne Henden's data:
R.A. 10h43m56.81s   Decl. +58o07'32.6"  (J2000.0) V= 17.906, B-V= +0.191

Time-resolved photometry and spectroscopy during the current outburst are very urgently required.



Subject: [vsnet-obs 18078] New Takamizawa variable (TmzV85)

New Takamizawa variable (TmzV85)

Kesao Takamizawa (Nagano, Japan) reports his discovery of a new variable star (TmzV85).

= USNO1425.07642945 104357.124 +580733.30 (2000.0) 16.3 16.9

   Takamizawa's comment:

The images were confirmed on two patrol films. I have checked known
minor planet.

If the USNO color is neutral, the star may be a UG-type with a range 
of 13.0-<15.3p. 

Photographic magnitude estimates by VSOLJ members

object         YYMMDD(UT)   mag  code
TmzV85         941111.792  <153p  Tmz.VSOLJ
TmzV85         950101.755  <153p  Tmz.VSOLJ
TmzV85         950207.704  <153p  Tmz.VSOLJ
TmzV85         950420.474  <153p  Tmz.VSOLJ
TmzV85         951118.781  <153p  Tmz.VSOLJ
TmzV85         960101.772  <149p  Tmz.VSOLJ
TmzV85         960407.480  <149p  Tmz.VSOLJ
TmzV85         970227.451  <144p  Tmz.VSOLJ
TmzV85         970330.490  <144p  Tmz.VSOLJ
TmzV85         970426.485  <142p  Tmz.VSOLJ
TmzV85         971026.719  <144p  Tmz.VSOLJ
TmzV85         971026.763  <149p  Tmz.VSOLJ
TmzV85         971101.753  <149p  Tmz.VSOLJ
TmzV85         971109.751  130p  Tmz.VSOLJ
TmzV85         971109.756  134p  Tmz.VSOLJ
TmzV85         980121.581  <149p  Tmz.VSOLJ
TmzV85         980322.550  <153p  Tmz.VSOLJ
TmzV85         980417.495  <149p  Tmz.VSOLJ
TmzV85         981024.812  <149p  Tmz.VSOLJ
TmzV85         981115.810  <149p  Tmz.VSOLJ

Observer's code:
  Tmz: K.Takamizawa (Saku-machi,Nagano,Japan)
       Inst.: 10cmR F4 twin patrol cameras  T-Max400 120
       Comparison stars mag.:GSC

(vsnet-alert 4035)

TmzV85 outburst confirmed

We started tonight observation on TmzV85, and confirmed the outburst. The current magnitude is 14.0, indicating that it is still in bright state (cf. vsnet-alert 4027 and 4028). We are planning 2-hour run on this object tonight.

Makoto Uemura and Taichi Kato

(vsnet-alert 4037)

TmzV85 eclipsing SU UMa-type dwarf nova in superoutburst!!!

From the data obtained last night ([vsnet-alert 4035]), we discovered that TmzV85 is SU UMa-type dwarf nova with eclipse. The light curve obtained last night clearly shows two superhumps and two eclipses. The eclipse is deep (1.3 mag), the duration of eclipse is about 15 min. The orbital period estimated from these two eclipses is 0.0736 day. The superhump amplitude is about 0.5 mag. This observarion confirms that TmzV85 belongs to a rare class of deeply eclipsing SU UMa-type dwarf novae.

We started tonight observation on TmzV85 at 10:00 (UT). We plan 10-hour observation tonight.

We will undertake an intensive observing campaign on this object, as we have had a very successful one in QY Per and DV UMa (in preparation for ongoing publications). Please post timely to vsnet-alert confirmatory observations, new findings, the progress of the outburst and observations.

Longer observations are strongly encouarged to precisely determine the physical parameters of the object. Collaborating observations should be sent (as usual) to We will set up a special page on TmzV85, as we have had on DV UMa and QY Per.

Makoto Uemura and Taichi Kato

VSNET light curve (requires Java)

Light curve

VSNET data search


TmzV85 identidfication
TmzV85 identidfication
Eclipse ephemeris
Orbital and superhump periods
Photometric sequence
TmzV85 astrometry
TmzV85 astrometry
TmzV85 identification

Masi's CCD image (FITS, in quiescence, south is up)

DV UMa (related system, 1999)

HT Cas (related system)

Representative light curve during post-superoutburst

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