[Aavso-photometry] ASAS 102522-1542.4 and ASAS 023322-1047.0 : update on data analysis

[Tonny Vanmunster]

Dear colleagues,

Over the past nights, additional CCD time-series observations have been
obtained for the newly discovered dwarf novae ASAS 102522-1542.4 and ASAS
023322-1047.0. Here's an update on the data analysis for both objects :

ASAS 102522-1542.4
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The initial outburst stage of this object was very well covered by CBA
observations from Tom Krajci, Lew Cook and myself. We collected 3
observation sets, with a total of 1236 observations, all characterised by
double-peaked "early superhumps" (or orbital humps). The duration of this
stage must have been pretty short : the discovery of ASAS 102522 was made on
Jan 26.2 UT (on Jan 25.2 UT, the variable was still below ASAS' detection
limit), and early superhumps lasted till Jan 28.5 UT. An analysis of this
initial part of the light curve yields early superhumps with a period Porb =
0.0615 +/- 0.0010 d, and with an amplitude of 0.04 mag (ANOVA method,
Peranso).

Starting Jan 29.0 UT, ASAS 102522 went into a different outburst stage,
characterised by the appearance of regular (full) superhumps. So far, we
have collected 5 observation sets (Tom Krajci, Pierre de Ponthiere, myself),
with a total of 2220 observations, covering this stage. The resulting light
curve clearly shows how superhumps have grown from an amplitude of less than
0.1 mag (Jan 29.0 UT) to over 0.25 mag (Jan 30.5 UT). Using the ANOVA
method, we find a superhump period Psh = 0.0637 +/- 0.0002 d.

The superhump period excess of ASAS 102522 thus becomes : (Psh - Porb) /
Porb = 3.58%, a value that is very well in line with expectations for a
system with an orbital period of about 1.5 hrs.

Both light curve segments, as well as the period analysis diagrams, are
published on my website http://www.cbabelgium.com


ASAS 023322-1047.0
------------------

Details on this dwarf nova have been published in my earlier email postings.
We recall that the (double-peaked) early superhumps had a period Porb =
0.05485 +/- 0.00026 d, and an amplitude of just below 0.05 mag.

The object entered its main outburst stage on Jan 28th, when full superhumps
started to dominate the scene. So far, we have collected 4 observation sets,
with a total of 952 observations, covering this stage. Using the ANOVA
method, we find a superhump period Psh = 0.05579 +/- 0.00027 d, and a
superhump amplitude of 0.3 mag. The superhump period excess value of ASAS
023322 thus becomes 1.7%.

Light curve segments and period analysis diagrams appear on my website.


With kind regards,
Tonny Vanmunster

Tonny Vanmunster
CBA Belgium Observatory
http://www.cbabelgium.com 
 
PERANSO : The Light Curve and Period Analysis Software
http://www.peranso.com

Attend the Peranso Workshop at the SAS 2006 Symposium on May 23, 2006
http://www.socastrosci.org/Files/home.htm