Possible New Dwarf Nova in Cetus (ASAS023322)

[drclay]

UPDATED JAN. 30 - Some fading has begun...(see measurements below)

There is a fairly bright new star (dwarf nova) in the constellation of CETUS, low in southern skies at dark for northern latitude observers; it is presently about magnitude 13.5 which makes it a good target visually for an 8-inch telescope or via CCD with even smaller instruments.  It has held this brightness now for about two weeks since its discovery by Bogumil Pilecki, Warsaw University Astronomical Observatory on January 20 at magnitude 12.0.

Below is a Jan. 25.1 (UT) image composite (6, 10-sec images) of the new dwarf nova in Cetus from ASO.  In addition note the detailed astrometric (positional) and photometric (brightness) measurements as obtained by ASO-H45 via CCD and Guide8/Charon software.

The new object is located at:
RA: 02:33:21.398 +/- 0.07 Decl.: -10:47:04.55 +/- 0.07 (J2000)
and presently at near 13.3 to 13.4 mag (R) as measured Jan. 25-26 at ASO with some minor oscillations noted.
Announcements and further updates on this object can be found at the ALERT site of the American Association of Variable Star Observers (AAVSO) at:
http://www.aavso.org/publications/alerts/alert333.shtml

From the VS-net, astronomer Brian Skiff remarks:
"These observations confirm that the CV in outburst is indeed the
usually-faint star near the original position.  Here is a summary of available
astrometry.  USNO-B1.0 shows modest proper motion of -2, +26 mas/year in RA,Dec
respectively."


  RA   (J2000)   Dec       epoch   source
2 33 21.375 -10 47 05.90   1953.9  USNO-A2.0 (n=2)
2 33 21.357 -10 47 06.28   1953.9  SuperCOSMOS  (POSS-I red)
2 33 21.367 -10 47 05.84   1979.7  GSC-2.2 (n=4)
2 33 21.384 -10 47 05.33   1993.8  SuperCOSMOS  (UKS F)
2 33 21.361 -10 47 05.33   1994.9  SuperCOSMOS  (UKS J)
2 33 21.366 -10 47 04.93   1999.9  SuperCOSMOS  (UKS N)
2 33 21.362 -10 47 04.94   2000.0  USNO-B1.0 (n=5)
2 33 21.393 -10 47 04.37   2006.1  H45 (n=6)

Measurements of ASAS 023322 by ASO/ P. Clay Sherrod:
COD H45
CON [drclay@]
OBS P.C. Sherrod
MEA P.C. Sherrod
ACK ASO Observations
AC2 drclay@
TEL 0.41-m f/3.3 Schmidt-Cassegrain + CCD
COM Reduction done using Charon
COM Charon version Jan 08 2006 12:23:52
COM Report file created Tue Jan 24 19:51:37 2006
NET UCAC2

Astrometric (first line)
Photometric [R] (following line on each data:
    Equipment:  0.41m RC with CCD (Texas Instruments TC-237 / 656 x 480 pixels @
7.4 microns square )
Dwarf Nova (?)

JANUARY 25, 2006
              C2006 01 25.07608 02 33 21.39 -10 47 04.1          13.1 R      H45
              C2006 01 25.07608      2453760.576076              13.08R      H45
              C2006 01 25.07796 02 33 21.40 -10 47 04.3          13.1 R      H45
              C2006 01 25.07796      2453760.577963              13.05R      H45
              C2006 01 25.08003 02 33 21.41 -10 47 04.5          13.3 R      H45
              C2006 01 25.08003      2453760.580035              13.21R      H45
              C2006 01 25.08187 02 33 21.38 -10 47 04.3          13.3 R      H45
              C2006 01 25.08187      2453760.581875              13.21R      H45
              C2006 01 25.08727 02 33 21.38 -10 47 04.5          13.3 R      H45
              C2006 01 25.08727      2453760.587269              13.21R      H45
              C2006 01 25.08845 02 33 21.40 -10 47 04.5          13.2 R      H45
              C2006 01 25.08845      2453760.588449              13.13R      H45

JANUARY 26 2006
 C2006 01 26.05570 02 33 21.38 -10 47 04.4          13.4 R      H45
              C2006 01 26.05570      2453761.555700              13.33R      H45
              C2006 01 26.05859      2453761.558594              13.49R      H45
              C2006 01 26.05973      2453761.559728              13.35R      H45
              C2006 01 26.08517      2453761.585168              13.42R      H45
              C2006 01 26.08747      2453761.587471              13.34R      H45
              C2006 01 26.08931      2453761.589311              13.36R      H45
              C2006 01 26.10462      2453761.604624              13.31R      H45
              C2006 01 26.10570      2453761.605700              13.40R      H45
              C2006 01 26.10690      2453761.606904              13.35R      H45
              C2006 01 26.11011      2453761.610110              13.18R      H45
              C2006 01 26.11172      2453761.611719              13.36R      H45
              C2006 01 26.11319      2453761.613189              13.39R      H45

JANUARY 30, 2006
ASAS023322              C2006 01 30.01492 02 33 21.40 -10 47 04.5          13.7 R      H45
              C2006 01 30.01492      2453765.514919              13.66R      H45
              C2006 01 30.01553      2453765.515532              13.60R      H45
              C2006 01 30.01609      2453765.516088              13.56R      H45
              C2006 01 30.04505      2453765.545046              13.77R      H45
              C2006 01 30.04561      2453765.545613              13.63R      H45
              C2006 01 30.04679      2453765.546794              13.82R      H45
              C2006 01 30.04796      2453765.547963              13.73R      H45
              C2006 01 30.06062      2453765.560619              13.60R      H45
              C2006 01 30.06173      2453765.561730              13.69R      H45
              C2006 01 30.06234      2453765.562344              13.52R      H45
              C2006 01 30.07663      2453765.576626              13.54R      H45
              C2006 01 30.07715      2453765.577147              13.52R      H45
              C2006 01 30.07797      2453765.577969              13.46R      H45


Photo (below): Jan. 25.1 (UT) image composite (6, 10-sec images) of the
new dwarf nova in Cetus from ASO.