[Aavso-photometry] NSV01485 - refined analysis of superhump period

[Tonny Vanmunster]

Dear colleagues,

Following my announcement this morning of the detection of superhumps in NSV
1485, I have now concluded a more detailed light curve and period analysis.
This yields an improved superhump period value of 0.076 +/- 0.001d, and an
amplitude of about 0.15 mag. 

Based on 6 nights of photometric observations between 2007, Aug 26th and
2007, Sep 07th, during quiescence of the variable, D. Denisenko (Space
Research Institute IKI) found an orbital period of either 0.0717d and
0.0771d (i.e., 14 and 13 revolutions per day). It was impossible to further
distinguish between these two aliases. My superhump period value clearly
favours the second orbital period alias.

I have published full details about my analysis, including LC, period window
and phase diagram on my website : www.cbabelgium.com.

Unfortunately, it's clouded over here tonight, so I can't follow up on NSV
1485. I would appreciate if someone could spend (at least) one other night
of CCD photometry on this target, to further refine the superhump period
value, and to maybe find other interesting signals in this system.

Best regards,
Tonny

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


-----Original Message-----
From: aavso-photometry-bounces at mira.aavso.org
[mailto:aavso-photometry-bounces at mira.aavso.org] On Behalf Of Tonny
Vanmunster
Sent: Thursday, September 20, 2007 5:17 AM
To: cba-news; Cba-Chat; cvnet-outburst at yahoogroups.com
Cc: aavso-photometry at mira.aavso.org
Subject: [Aavso-photometry] NSV01485 is an UGSU-type dwarf nova

Dear colleagues,

Patrick Schmeer today announced another outburst of NSV 1485, occuring only
a few days after the end of the previous one. I spent 3 nights of photometry
covering that outburst, which turned out to be a normal one. See
www.cbabelgium.com for a lightcurve.

The sky started to clear out around 0h30m UT tonight (2007, Sep 19/20), so I
initiated an unfiltered CCD photometry session on this target, using
telescope #1 at CBA Belgium Observatory (0.35-m f/6.3 SCT, ST-7XME CCD). A
preliminary analysis of the resulting lightcurve, based on a 2.5 hrs run,
clearly reveals the presence of superhumps, hence classifying NSV 1485 as a
new UGSU-type dwarf nova. A quick period scan, using Peranso's ANOVA method,
yields a value of 0.074 +/- 0.002d, and an amplitude of about 0.15 mag. 

It is most likely that superhumps will further grow over the next nights.
Given also the small baseline of my current observations, I strongly welcome
additional CCD photometry to refine the superhump period. Evidently, V455
And should remain a prime target for all of us (telescope #2 at my
observatory is working on that one), but if you have some CCD power left,
then ...

I will post my NSV 1485 lightcurve and period analysis results on my website
later this evening. I have to get some sleep now ...

Enjoy your CV observing !

Best regards,
Tonny


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

Aavso-photometry mailing list
Aavso-photometry at mira.aavso.org
http://www.aavso.org/mailman/listinfo/aavso-photometry


____________________________________________________________

Center for Backyard Astrophysics (CBA) mailing lists
http://cba.phys.columbia.edu/communications/mailing-lists/