[vsnet-chat 7439] V358 Lyr analysis

[Gary Poyner]

----- Original Message ----- 
From: "Jeremy Shears" <bunburyobservatory at hotmail.com>
To: "CBA-chat" <cba-chat at cbastro.org>; "CVnet-discussion" 
<cvnet-discussion at yahoogroups.com>; <aavso-photometry at mira.aavso.org>; 
<baavss-alert at yahoogroups.com>
Sent: Wednesday, December 24, 2008 9:12 AM
Subject: [baavss-alert] V358 Lyr analysis



I have analysed photometry conducted by several members of CBA, AAVSO and 
BAA obtained during the outburst. This includes data from Tom Krajci, Bob 
Koff, Tut Campbell & George Roberts, David Boyd and Shawn Dvorak, either 
sent directly to me or downloaded from the AAVSO International Database. 
Many thanks to these observers who persevered with a challengingly faint 
target in a poor sky location!

The first conclusion is that, by visual inspection of the light curve, there 
is no obvious modulation such as superhumps - that we pretty much knew 
already and there have been several discussions on the user groups as to why 
this might be.

Period analysis using a variety of algorithms in Peranso gives the largest 
signal at 0.057 d (82 min). However, there are many other peaks in the power 
spectrum and this signal is not particularly strong. The False Alarm 
Probability given by Peranso is 1%, which is on the borderline between a 
secure period and a spurious one. On this basis I cannot claim this to be a 
significant period.

One way to rule this period in or out would be to include more data in the 
analysis, especially if this were obtained at other longitudes - one problem 
we have is that the runs were necessarily rather short due to the location 
of the star. Therefore if you do have further data on this star, I would be 
delighted if you could send it to me.

Jeremy Shears,
Cheshire UK